EPISODE 29

[INTRODUCTION]

[00:00:00] ANNOUNCER: Do you enjoy listening to On The Ear, but wish you could earn ASHA CEUs for it? Start today. Speechtherapypd.com has over 175 hours of audio courses on-demand, with an average of 19 new audio courses released each month. Here's the best part, each episode earns you ASHA Continuing Ed Credits. Oh, no wait. This is the best part. As a listener of On The Ear, you can receive $20 off in annual subscription when you use code Ear21. Just head to speechtherapypd.com to sign up and use code Ear21, E-A-R-2-1 for $20 off your annual subscription.

[00:00:48] DS: You're listening to On The Ear, an audiology podcast sponsored by speechtherapypd.com. I'm your host, Dr. Dakota Sharp, Au.D, CCC-A, audiologist, clinical professor and lifelong learner.

While I primarily work with pediatric cochlear implants and hearing aids, I am absolutely intrigued by the many areas of audiology and communication in general. This podcast aims to explore the science of hearing, balance and communication with a variety of experts in hopes of equipping you to better serve your patients, colleagues and students. Let's go. We are live and On the Ear, brought to you by speechtherapypd.com.

[INTERVIEW]

[00:01:35] DS: Our understanding of the listening needs of children with hearing loss has drastically evolved over the past decade thanks to the collaborative efforts of clinicians and researchers like the Outcomes of Children with Hearing Loss study. This multidisciplinary team of professionals from the University of Iowa, Boys Town National Research Hospital, and the University of North Carolina in the fields of audiology, speech language, psychology, linguistics, biostatistics, they all focused on examining the impact of newborn hearing screening, early intervention and advances in hearing technology on a wide range of developmental outcomes for children who are hard of hearing. Their research continues but has shifted and evolved itself and today's guest is going to provide a close up look at their groundbreaking results.

Dr. Ryan McCreery is the Vice President of Research at Boys Town National Research Hospital in Omaha, Nebraska, where he provides strategic leadership to the 42 laboratories across research groups in audiology, language, neuroscience, and behavioral psychology. In his own laboratory within the Center for Hearing Research, Ryan studies how to optimize hearing aid fitting for infants and young children who are hard of hearing. Ryan received the 2013 early career contributions to research award from ASHA and received recognition as an ASHA fellow in 2020.

He gave the 2021 Marion Downs Lecture in Pediatric Audiology for the American Academy of Audiology. Just a few financial disclosures. I'm a paid employee of the University of South Carolina and receive compensation for hosting On The Ear from speechtherapypd.com. And Dr. Ryan McCreery is a paid employee of Boys Town, a consultant for the British Columbia Hearing Program and receives funding from the NIH. He received compensation from speechtherapypd.com for this presentation.

Ryan, I got to say, you're one of my audiology heroes. It's so cool to have you on the podcast. The work you all are doing is so important and directly impacts my clinical practice regularly. And the resources on your website are so awesome. So, I can't thank you enough for joining me.

[00:03:20] RM: Well, thank you, Dakota, this is fantastic. I'm a big fan of the podcast as well. And so, it's really a huge honor for me to be here and to have the opportunity to talk about our results with you, where you saying that the work has an impact on you as a clinician is probably one of the biggest compliments that we can receive.

[00:03:37] DS: Yeah, well, you listening is about the biggest compliment I should receive. So, right back at you. Thank you so much. Okay, so just to help me, I want to kind of get into your backstory a little bit too, because I think I don't have the entire backstory. But I'm pretty sure you started clinically and now you're in this like major research role, and I'm so curious about that. But before I do, so there's the OCHL, the Outcomes of Children with Hearing Loss, and now there's also the OSACHH, which study are you guys on now? Because I know you've got a lot of teams working together, you have a lot of subjects going on here. What's the best way to describe what you're currently working on?

[00:04:16] RM: So, the study that most people are familiar with, that I was involved in is the Outcomes of Children with Hearing Loss study that you mentioned at the sort of beginning of the podcast. And that was a study that was led by Mary Pat Moeller and Bruce Tomblin, and Melody Harrison, and those amazing scientists started that project in 2009, with the goal of recruiting a large sample of kids who are deaf and hard of hearing, particularly kids who wore hearing aids, to look at their language outcomes. In the process of that, I got involved. I had just finished my PhD and they were interested in bringing someone onto the team who had some expertise in hearing aids.

So, I got involved in the OCHL project sort of as a junior investigator. But when we went back to the NIH to try to extend the project for another five years, and I said, “Yeah, we'll let you do that. But we're going to hold you to a much smaller budget limit that you had the first time”, which is completely reasonable, because the original budget was part of a special pot of money that the NIH had. So, we had to get really creative and one of the things they wanted us to do was to break apart the speech and language and hearing research. And we had Mary Pat Moeller and Bruce as the PIs of the speech language and academic grant. And that's the OSACHH grant or Outcomes of School Aged Children Who Are Hard of Hearing, that you mentioned. And then the audiology sort of complement to that grant was called the Complex Listening Skills in School Age Hard of Hearing Children. So, we just call that one complex listening.

[00:05:57] DS: Got it.

[00:05:58] RM: We had two grants, that ended in 2019. And since then, I've renewed the complex listening grant, and then we have another project that I'm excited to talk with you about called Fast Track, which is focused on children with mild bilateral hearing loss specifically.

[00:06:14] DS: That's great. That's a really helpful picture. Because I know, I see some of the wording on the website refers to things in the past tense, but I still see you all as a group, publishing studies. So, I'm like, “Are they using data that's been collected over time? Or are they working on something totally new?” So, that's really helpful and I'm really excited to talk about that, too. I've got a few mild bilateral kids on my caseload. I'm curious what kind of information you've got for us there.

So, before we get into that, though, how about you tell us a little bit about how you got into more of a research role? And what was your primary interest in hearing aids before that?

[00:06:46] RM: So, I started out as a pediatric audiologist. I did my Master's in Audiology at the University of Nebraska Lincoln, and I had considered going straight through to finish my PhD right after my Master's. At the time, I just didn't feel like I was ready to get a PhD. And every one of my professors said, “Don't go and get a job, or you'll never come back for your PhD.” I thought, “Well, if that's the case, I'll know that that's the right thing to do.” And I was a clinical audiologist for 10 years. But during that time, I had the opportunity to work with Pat Stelmachowicz. Pat was the Director of Audiology at Boys Town, and she was my boss when I was a pediatric audiologist in the clinic. And we would have conversations about research because Pat had her own funding and she studied how to optimize hearing aid fitting for kids with hearing loss. 

At the time, she was one of the only people that was funded by the National Institutes of Health to do pediatric hearing aid research. So, as I would ask Pat questions, she would say to me, “You should go back and get a PhD.” And I was like, “I've heard this before, from my professors in my master's program.” And so, Pat was really the catalyst who encouraged me and I started out just working as a research audiologist in Pat's lab. But then I got hooked on research and really became very interested in pediatric amplification and realized how many interesting questions that were that we just didn't have answers to.

I was able to do my PhD in Pat’s lab through the University of Nebraska Lincoln. And my PhD is actually in human sciences, because of the courses that I took in sort of experimental psychology and statistics. It's been a great experience, because I have the audiology background. But I also got really diverse background and other topics when I did my PhD. So, I joined Boys Town, as a scientist in 2011 and I started my own laboratory and then started writing my own grants. And then Pat retired from her position as director of audiology, and they were looking for a new director of audiology, and I thought, “Well, I'll put my hat in the ring, even though I'm kind of new.” And then I became director of audiology. And then the same thing happened with the director of research.

I had established the lab and had written some grants, and they had been looking for a director of research, and I thought it would be a good time for me to sort of take the next step and do something a little bit different. Because the audiology program at Boys Town is is amazing and has great leadership and I was really ready to try something a little bit different. So, that's how I ended up in this director of research role, but my heart is still in the audiology department. I still bother our audiologist all the time with questions about how things are impacting them or what ideas they have. So, it's a great place to be because I have a role over research, but I also still get to interact with my colleagues in audiology, which I love.

[00:09:54] DS: That's awesome. That's awesome. It's great. I know we're going to talk about Fast Track later but it sounds like you've got, like a career fast track. You just jumped up a lot of places. But it's clear that your work is really impactful. I know just in that short amount of time, some of the data that's come out from the studies you all have published has just like drastically changed clinical practice for pediatric amplification, and just been really, really important. So, I'm curious. I mean, I know you kind of came into the project a little bit after it was established. But if you have any insights into how the OCHL study was kind of established where those initial research questions came from. And maybe, how those questions evolved a bit over time?

[00:10:35] RM: Yeah, so there's a really interesting supplement to the Journal Ear and Hearing that came out in I think, 2006 or 2007. But it was a consensus conference that was hosted by the National Institutes of Health, and the National Institutes on Deafness and Communication Disorders that funds a lot of research in hearing and speech and language. And it involves people like Mary Pat Moeller and Bruce Tomblin, who eventually would lead the OCHL study, but it also included some really amazing people like Susan Joerger, who everyone knows Susan Joerger’s husband, Jim, as sort of the godfather of audiology. But Susan Joerger will always hold a special place in my heart because she has contributed substantially to the field of pediatric audiology throughout her career.

She published some interesting work there and those papers that came out of that consensus statement from that special issue of ear and hearing, really laid the groundwork for the OCHL study. And in fact, if you read those consensus documents, and then you go and read the supplement that describes the results from ear and hearing, from the OCHL project from 2015, you'll see that there's a lot of parallels there that was really inspired by that consensus conference, and that that really had a huge impact on the development of the project.

It started out really focused on the speech and language outcomes for these kids, because that was a big goal of the conference. But fortunately, there were a lot of people who were involved in the project early on, like Pat Roush from the University of North Carolina, and Melody Harrison from UNC, as well as Pat Stelmachowicz, Ruth Bentler, Lenore Holte, all of these amazing pediatric audiologists who really pushed for looking at that relationship between amplification and language outcomes. So, not just looking at sort of older questions like if you fit the child early, do they have a better outcome? And those are really interesting questions before newborn hearing screening was fully implemented.

But now that such a large percentage of kids are identified through newborn hearing screening, we really need to know and understand what are the factors that create that individual variability for kids that were identified very early and that was sort of the wonderful foresight. So, even though that was sort of established before I was in the meeting, and in the team, it was very well set up by those people who were part of the project. They did my career such a huge favor, because I now have the opportunity to look at this wonderful data set that includes details about amplification that were never available in previous studies.

[00:13:20] DS: Wow. So, I, from what I understand, it's just the way you said it, it's picking apart some of those factors. Because even though we did have a dramatic increase in early identification in newborns, there were still a lot of variability in speech and language outcomes in children with hearing loss who wear hearing aids. So, I guess those were the questions, right? Is like picking apart which factors had the biggest impacts. So, as that study progressed, was there anything that looking back now to you was really surprising, or really, I mean, I know a lot of the information and a lot of the published research is really interesting, but anything that really sticks out to you are like a take home message like to give to people?

[00:14:01] RM: Yeah, so this is going to sound weird because of my area of interest in my own research, but I guess I had always underestimated the impact of the hearing aids on the outcome. I view the early intervention process for children who are deaf and hard of hearing as this very comprehensive sort of list of factors. So, things like how early they get an intervention, what type of intervention that they have, the family systems dynamics. There are all kinds of awesome research going on out there into all these factors. 

And I guess, even though, I was an audiologist, and I fit hearing aids on infants and young children and saw the huge benefit about that and counseled families about how important it was for them to use their hearing aids, I guess I had always downplayed. I always viewed the hearing aid is like a little piece of that puzzle, but what we're finding is that along with the language environment that the child experiences, which is obviously extremely important that that hearing aid use and how well the hearing aids are fitted is such a huge part of the outcomes. And that to me, the relationship wasn't surprising. I always viewed it as part of it. But what was surprising was just how dominant that has been.

[00:15:20] DS: Yeah, that's really interesting and I know a lot of your research as well is focused on audibility as a big factor, in terms of when it comes to the fitting, focusing on that audibility and incorporating the speech intelligibility index a bit more. What led you to look into that as a factor of the hearing aid fitting? Or you know what I mean? Kind of what led you down that road to explore those questions a little bit more deeply?

[00:15:46] RM: Yeah, that's a really interesting question. I think the first component of that was that my mentor, Pat Stelmachowicz, who was involved in the development of the study, even her research around 2000, 2001, was really focused on this concept, that if spoken language is the goal for a specific child who's deaf or hard of hearing that children are only going to develop sounds that they can hear. So, she and Mary Pat Moeller did some research studies where they looked at children who are early identified with hearing loss. And what was interesting was, they did better than the children who were later identified, obviously. But they were still falling behind their peers with normal hearing in terms of specific types of speech sounds. And when they looked specifically at what speech sounds, the kids were missing in their phonetic inventory, it was fricative sounds.

Sure enough, they looked at the fact that the hearing aids didn't have the bandwidth to encode those S and SH, and F and V sounds. So, it wasn't surprising that these kids weren't developing these sounds because they couldn't hear them. That was really the first sort of step into audibility that I think the field had. I was obviously heavily influenced by the research of those two wonderful people. Where we started to incorporate the speech intelligibility index, was when we started to notice that we were seeing kids that had sort of the same audiogram, but they were giving us really different outcomes. You hear that from pediatric audiologists like all the time. You say that to a group of pediatric audiologists and they're like, “Yeah, that's my life”.

But we were thinking, well, what's the factor here that's predicting it? We found that the audibility, through the hearing aids is a really potent predictor of language development, and specific areas of language like morphosyntactic development, where you need to have those fine-grained cues to learn those morpheme endings to words and things. So, it's just grown from there with each sort of different research question and each experiment. People get tired of me talking about audibility, but it's just such a huge component of the process, and the other beautiful thing about it, is that it's something that we as pediatric audiologists can influence.

So, the audibility is really determined by the degree of hearing loss, which there's nothing that we can do about, and how well we fit the hearing aid, which is absolutely something that's within our control. There's something very appealing to me about the idea that a pediatric audiologist is having this amazing and profound impact on the language development of these kids by following best practices and doing hearing aid verification. That's been really something that's driven me to continue to explore audibility.

[00:18:42] DS: Yeah, that's really cool. I like that picture a lot of the difference between the two of what's in our control and what's out of our control. I also love it. I mean, I don't get tired of listening and talking about audibility. I also love it just because like, it's like a numerical value. It's like when you hear someone say, like, “I've got a 50% hearing loss”, an audiologist all like groan, they're like, “What are you talking about?” But with SII, like, no, there is a number, like I can look at this number and compare it to another number. It's really helpful in that way. It's not always a perfect picture. But I do appreciate how some of the research that you guys are doing is giving us a little bit more of like concrete, objective comparisons between things, where historically it's felt like a little bit more up in the air always on a case-by-case basis.

So, I do appreciate that research, for sure. Maybe this is just sort of like a question about big longitudinal studies in general, which I have very little experience with. But when it comes to like how these research questions change, as you guys get more information, what leads you all to start a new study with a new research question that's all enveloped within one multicenter study? I know this is like a really — that was a really long, complicated way to ask that question. Do you get what I'm asking there?

[00:19:58] RM: Yeah. It's a great question. I would say the process usually begins long before we plan to implement the study and we try to be really transparent from the beginning about our goals and expectations for the study, because as you may know, from just being a consumer of science and your interest in research, there's a big emphasis right now on open and transparent research. So, when we start a research study, we really try our best to set up our expectations and our hypotheses ahead of time at a big picture level, meaning that we were defining things and we've even started to pre-register some of our studies where we publish the method that we're going to use ahead of time so that people can go back when we publish the actual work and say, “Yes, they did what they said they were going to do, and there's no sort of statistical malfeasance here, or that they're not trying to gain the statistics to get a specific outcome.”

But with that being said, there's a lot of interesting questions that just arise sort of opportunistically. So, you can't possibly plan out every interesting thing that comes up. And we found relationships with, you know, for example, that relationship that I mentioned between audibility and children's morphosyntactic ability, that was not a planned part of the original analysis. And looking back, it's like, “Well, we should have put that in the grant.” But you don't necessarily know when you're designing the study, or designing the grant what your opportunities are going to be. So, I think, we try to define it as well as we can, so that we have a good plan, and we're getting good data.

But I think some of these questions that have come up, have really come up out of opportunities or conversations with clinicians about, or questions from clinicians. If we go to a meeting and present, we get awesome questions. And sometimes those questions inspire us to go and look at something that we hadn't even thought of. So, we try to keep it structured, but you also don't want to close the door on potential, sort of what we call exploratory experiments that weren't part of the original plan, but are very interesting and often have really important clinical implications.

[00:22:22] DS: That's great. That's a really helpful insight into that process. I'm also curious how you all just like — I mean, this is probably something that researchers deal with all the time. But as a clinician, I never have to think about. Just like managing data across sites across the country and different time zones. Do you all just have a Google Doc that you keep going? Or I'm guessing, there's probably people who are hired to manage your data. But I'm just curious how that communication is maintained across such a wide distance?

[00:22:51] RM: That's a really awesome question and a good insight, because it is so challenging when you're doing a multicenter study. So, it starts really with training the people who are collecting the data. And fortunately, in our multicenter studies, we have amazing audiologists, and speech language pathologists who help us to collect the data and the fidelity of their efforts is so strong, and they have monthly meetings where they talk about challenges to the data collection process.

So, these are just such dedicated, amazing people. It really starts with the fidelity of the data collection. And then we do currently sort of a cloud-based data approach using a system that was developed at Vanderbilt called REDCap. And REDCap allows you to build sort of data entry forms, that really constrain the values that can be entered, so that you know that what you're getting is plausible and there's also ways to sort of do data reliability.

So, the examiners at each site, in addition to just being fantastic clinicians, also then either pass along to a research assistant or themselves, enter the data into REDCap, which then goes through some quality checks to make sure that everything like you're saying with timing and the appointments, lines up, and it's a really nice system. Because if you're doing a longitudinal study, and let's say you want to see a child back in a year, you can create additional appointment reminders, essentially, in REDCap, that will tell you, “Yeah, you need to bring this group of kids back because you said you were going to.” So, it's a really great way to manage a longitudinal study, because it's interesting, but at least at the stage that we're in right now, that data collection and data entry is so much more critical than the — I mean, the experimental design is important, but once that's set into motion, it's really about the data collection and data management and you're absolutely right. We have amazing people whose job is entirely to help us manage the data, and that's such an important role.

[00:25:03] DS: Yeah, I can't imagine with all of the different outcomes, you guys are measuring across so many different professionals, it's got to be a lot, and a lot of different lingo and different kinds of examinations and scores. I just cannot imagine the amount of data. But as a researcher, I'm sure, you're like, “Hey, it's, it's all opportunity of numbers to look at and consider.” So, as you all transitioned, this is out of curiosity, from the OCHL study to the OSACHH, as you transition from those two, is it the same pool of subjects who are just growing up into school age? Or did you all find a new set of subjects to begin this kind of stage of the research? Just curious how that process changed over time.

[00:25:45] RM: Yeah, so we use kind of both strategies in both complex listening, and OSACHH where we have this wonderful group of kids that participated in our studies that were so well characterized in terms of their early auditory experience and their intervention. So, we've absolutely continued to follow some of those kids. My colleague, Beth Walker, at the University of Iowa, currently is doing a study on language and literacy outcomes for these kids. Some of the children that she's following in her literacy study are teenagers that started out in this study as young children.

We've got almost over a decade of data on some of these kids. But there's also a challenge when you have a longitudinal cohort that you've been following for as long as we've been following these kids, and that the numbers sort of dwindle over time. So, in our more recent grants, what we've tried to do is incorporate cross-sectional questions and longitudinal questions, so that if we get new volunteers to participate in the research, we can incorporate them into the experiments as well. But then we've also got this beautiful, longitudinal cohort, and we tried to do both, because one of the things that we learned early in the OCHL study was that the longitudinal questions are very interesting and great. But if you do a longitudinal study, and you don't plan any interim cross-sectional analyses, you don't have any research papers published at the end of the grant.

[00:27:20] DS: Oh, gotcha.

[00:27:21] RM: And NIH says, “That's bad.” You can't just save it all for the end, and you're not going to get the grant renewed. So, in our subsequent grants, we've really tried to include both cross sectional and longitudinal analyses, to allow for those continuing subjects, but also to give opportunities for other children and families to participate in the study. Because it's become quite a — the families that participate, love it, and they’re so dedicated to this work. It's just awesome.

[00:27:52] DS: That's cool that you're just with them through their life. I don't know if you've seen the movie Boyhood, but it's like a movie that filmed him a few years at a time over the course of his life and you guys get to see that. I mean, it's similar to what a clinician has that relationship with a patient, as a pediatric audiologist, if you're there at diagnosis, and you can follow them all the way through when they age out, it's just cool to see that from a research perspective, too. I'm sure because there's so many professionals involved, some of the researchers I've worked with, a lot of times it's like, a day long thing for this participant where they come in, and they see audiology, and they see all these other people for the data collection. And it's like, going to camp for the day, and then you guys build a lot of relationships, I'm sure.

[00:28:29] RM: Yeah, I mean, I feel like we've known — I mean, you really have gone through these family’s lives and clinicians experienced the same thing. I remember, towards the end of my tenure as a clinician, I was getting invited to high school graduations. When you follow kids for a long time, you get to know them, you get to be part of the family. I worked with audiologists who've worked for 30 or 40 years and get invited to weddings, and then see — and the OCHL group is a lot like that too, where we know those families, and they're our biggest resource and have really made the study successful, because without them, we wouldn't be able to do any of the work.

[00:29:10] DS: Gotcha. That's awesome. That's such a cool part of your job, I'm sure. I'm also curious, so I know the OCHL study, some of the big things you're looking at are those factors that are impacting speech and language outcomes when it comes to children who are deaf and hard of hearing. But I'm curious how — I don't know as much about the OSACHH study in the complex listening study. So, what are specifically those to looking at?

[00:29:32] RM: So that's a great question. It has to do with the sort of ages of the children that were in those two studies. So obviously, with the OCHL study, we were starting out with infants in many cases. And we use an accelerated longitudinal design so that at the beginning of the study, we didn't just recruit babies. We recruited kids across a range of ages from six months of age to six years, because we knew that we only had five years of funding. So, we wanted to characterize a much broader range. We followed all those kids, and what we found at the end of OCHL was that we were really interested to see how these kids were doing in school.

So, OSACHH really focused on things like reading and writing and literacy, specifically, and how language abilities sort of set the table for those important academic skills. Whereas complex listening really focused more on classroom acoustics, listening in noise and reverberation. So, school aged listening activities that we really didn't have a lot of information about. I mean, I know a lot of audiologists will appreciate that reverberation is generally not a positive factor for classroom listening. But there have been so few studies of how amplification affects listening and reverberation despite the fact that nearly all of the kids that we follow in the clinic or in our research studies have to listen to noise and reverberation. So, we really changed the focus from like early childhood language, to more academically based outcomes for both audiology and the speech and language group, as well as the psychology group. It was like the studies grew up with the kids.

[00:31:18] DS: That's awesome. That's really awesome. And what a cool way to think to conduct the study too, just to have that ongoing relationship. Are you all also providing interventions? Or is this purely like we're checking in, either once a year or a few times a year, and then is it also looking at like intervention outcomes kind of thing? I know there are some studies that do that as well.

[00:31:42] RM: Yeah, so that's a great point, because we, as part of the study, tried really hard not to provide intervention. So, we would document the intervention that the children were receiving. But the children that we followed weren't just patients at Boys Town, or the University of Iowa, or the University of North Carolina. They were recruited from 17 US states, and they were seen by a wide range of audiologists and early intervention providers. One of the challenges with that is that we saw a lot of children in the study whose hearing aids were poorly fitted. We had a real, ethical concern about that, because we didn't feel good about letting kids walk around with amplification that was poorly fitted. But by the same token, if we had fixed all the poorly fitted hearing aids that came through the clinic, that really wasn't within the purview of our role as researchers to sort of modify their intervention, and it would have changed the study. That's not what we set out to do.

But as a pediatric audiologist, I was having heartburn, seeing some of these kids walk into the, to the research study visit with such poorly fitted hearing aids. And so, we kind of came up with a compromise, where we weren't going to change their intervention. But if we saw a child whose hearing aid was poorly fitted, we would send the audiologist a letter and the parents a letter and say, “Hey, we saw them for research and their hearing aids are not well fitted.” Unfortunately, the situation that created the poor fitting in the first place, meant that oftentimes those professionals wouldn't modify the hearing, even when we notified them about it. So, it was a challenging situation, but we definitely did not want to provide intervention, because that's not what we set out to do in the study and that wasn't what our research questions were. But the clinician part of me was often very distraught at what we were seeing. But now we're trying to use that information to show the audiologist that the kids who were well fitted and had the best outcomes, and so the work that we do is so important for that.

[00:33:46] DS: Yes. I mean, that's crazy. I'm really glad that you shared that. That's a really helpful insight into kind of the research process, because I can't imagine not fixing any problem that arises. But you're totally right. That's not how research works, we'd never be able to answer questions if it was just constantly intervening. But yeah, I can't imagine having to navigate that as a clinician who has seen so many patients before. And also, you're doing research that's looking at the impacts, and you're seeing the impacts in a way that you know how badly they need this. I mean, that's got to be so hard.

Actually, that's a pretty good question. So, again, the team, I guess, it's a multidisciplinary group or team the project has put out so much research. I'm just curious. I mean, this is usually a part of most people who go through audiology training is understanding research methods and how to integrate research into your clinical practice. But do you have — I know you do a lot of presentations for audiologists like all over the world. So, I'm curious, do you ever get questions about like, “Hey, this is a great study. I think this information is awesome. How do I integrate this into what I'm doing right now?” And if you get a question like that, what do you say to that clinician?

[00:34:56] RM: Well, I think one of the things that we're really trying to do, and I mean, I would love feedback from clinicians on how we can do this better, because to me, it's where the rubber really meets the road, is what we try to do (and again, the clinicians would be the ones have to tell us if we're successful), but we really try to think about the clinical process and how the factors that we are identifying fit into that clinical process. There's lots and lots of examples of that related to hearing aid verification, or I know some of my colleagues who are speech language pathologists will often talk about the strategies that are best for sort of optimizing language intervention for families and things like that. But it can be really hard when you're sitting there from the research side of things.

So, we just really try to listen to what the clinicians are telling us. And instead of trying to go and say, “Well, this is what we found, and this is what you need to do”, talking with them about, well, if you are going to increase hearing aid use in your patients, what do you feel like have been the strategies that have worked best for you clinically? Because as a researcher, I can look at the data and say, “Yes, we need to increase hearing aid using kids.” But it's a bit presumptuous for me to go into a clinic and tell someone, “Well, this is how you should do it.” So, it really is a partnership, and I think that stems from the fact that so many of us who were involved in the project had careers as clinicians prior to the study, that we really — we feel like that's influenced us pretty considerably in terms of how we approach that question.

[00:36:31] DS: Yeah, that's a great insight into that process and I think it's really helpful. I think, I'm fortunate that I'm in a university setting, and I'm around researchers all the time. But I have to imagine that a lot of clinical audiologists don't have a really close up look at how research is conducted. And so, there's sometimes can feel like, that disconnect between what I'm doing every day clinically, versus what they're doing in a lab kind of basis. So, I think it's awesome that you guys approach it that way. I'm so appreciative that your team puts out the resources as like posters. Is that the best way to describe those that are on your website?

[00:37:09] RM: Yeah, we call those infographics. I don't know that that's even the right terminology for them. But we really feel like presenting the research that way is making it accessible to different audiences. So, you'll notice we have some for parents, we have some for audiologists, we have some for early intervention providers, and that's great feedback for us. Because that's definitely our goal.

[00:37:34] DS: Yeah, it's extremely helpful to be able to show that to a family or to show that to a clinician. it's short and it’s sweet and it's got great visuals. I'm just very grateful for those. I don't know too many studies that like, put out like a simplified infographic of the results. It's a really, really great concept and I'm very appreciative. I hope you guys keep doing that.

So, when you think of the OCHL study, the OSACHH study, and the complex listening study, compared to when you were practicing clinically, what do you feel like have been some of the biggest revelations or biggest shifts in your clinical thinking or clinical understanding that have come with each of those? I know that's kind of a big question, because I'm asking for like, the three different studies. But if you've got a couple from OCHL, or OSACHH, or complex listening.

[00:38:21] RM: Yeah, I think the biggest one from OCHL was just how important amplification is for kids with milder degrees of hearing loss. I think when I started out, as a clinician, there was a lot of what we call in the research world “clinical equipoise”, about fitting kids with mild bilateral hearing loss with hearing aids. I was just absolutely blown away by how these children who had mild bilateral hearing loss were experiencing, in some cases, deficits that were greater than the children with moderate degrees of loss. That was very surprising to me, and a finding that extended from the earliest outcomes that we looked at all the way into the academic outcomes for the kids. And that really was a huge sea change for me, because I think I sort of had this sort of ambivalence about mild hearing loss as a clinician, and now I'm like a crusader against mild hearing loss.

The other thing that I think that really shifted my thought process is we don't often think about the importance of hearing aids in all kinds of different listening situations. And we really consistently found that I think maybe it comes from the adult hearing aid research where we are trained not to tell people that hearing aids are going to help them to hearing background noise. But what's interesting is if you look at the kids who do really well in background noise, they’re the kids who have the best audibility through their hearing aids. So, I think we don't want to overstate the fact that kids who are deaf and hard of hearing who use hearing aids are still going to have difficulty in background noise relative to their peers with normal hearing, like that is still true.

But if you want to give that child who's deaf or hard of hearing the best possible outcome that they can, you want to fit those hearing aids to have the best audibility possible, and give that child the best chance that they have, because there are children who are performing extremely well in background noise with their hearing aids, and the common theme is that they all have good access through their hearing aids. That's something that for whatever reason, as a clinician, to me, I always remember, “Oh, they're just not going to perform as well as their peers with normal hearing.” But if you look at the kids who are performing the best, they have the best access. It makes sense, but I think, for some reason, I always got hung up on that old statement that hearing aids aren't going to help as much background noise, and we need to focus on remote microphones.

I still believe that. But I do think we need to maybe change how we talk to families about it. Because there are definitely situations where remote microphone is not a plausible communication option, and we want to give kids the best access we can and get the best audibility is the way to do that.

[00:41:16] DS: Yeah, that's a really, really valuable insight. Correct me if I'm wrong, I feel like I might have read a study that was looking at early intervention with hearing aids as a predictor for performance in background noise. It was something about like — because I think it makes sense that the earlier that we can stimulate whatever pathways our brain is doing to perform better in noise, rather than being fit later with hearing aids with mild bilateral hearing loss, does that make any sense? Do you know the study I'm talking about? Or am I just making this up? 

[00:41:45] RM: What you just described is there are several studies now including studies that we ourselves have been involved in that show this pattern. So, the way that I think about this is that having good audibility through your hearing aid is really important so that you can hear what you're trying to listen to. We call that sort of the instantaneous effect of audibility. But the underrated factor, and the one that came out of the Outcomes of Children with Hearing Loss study and the subsequent studies is that wearing your hearing aid consistently and getting good audibility, also has a cumulative effect on the cognitive and linguistic skills that help you to listen and background noise.

So, in addition to getting a benefit to just being able to hear better, you also are developing the working memory, executive function and language skills that listeners use when they're listening to degraded speech. So, another way to look at it is if you're a child who has limited auditory access, you're not only going to struggle in your environments, but the compensatory skills that you're going to have, are also going to be affected. That's been a fascinating effect, because I think we've understood the instantaneous effect of good audibility for a long time. But that we haven't always been able to put our finger on this cumulative effect and that's what a lot of our most recent research is focused on.

[00:43:11] DS: Wow, wow. Okay, so yeah, thank you for making me not feel crazy, but I swear I'd read something about that. So then, with the OSACHH study, is there any particular finding that really struck you as maybe something you didn't expect? Or maybe you did expect it, but it was really cool to see the data support that hypothesis?

[00:43:29] RM: Yeah, I mean, I think the coolest thing is that hearing aids help with academic outcomes, as well. So, when we looked at things like writing and math, I had always thought, you know, we're doing a lot to help these kids in terms of their language ability, but to see the downstream impact on academic topics was just like, very important for me. It pulled the whole thing together, and now that I've worked with all these really smart language scientists, I understand the mechanism behind that. But I guess, as an audiologist, I didn't really put two and two together in terms of how the language piece really informs the academics and the hearing aid ties in with that, and being able to make that link has been very cool.

[00:44:18] DS: That's awesome. That's awesome. And yeah, just to have that direct evidence that support something like that, too, is really helpful. I love the crossover, too, and the education that you guys must be doing. I'm curious how, I mean, I guess the OCHL study probably had a little bit of educator involvement, but by the time you get to the OSACHH study, I mean, are you guys directly involved with teachers of some of these children? How was that shaped? Because there's a lot more professionals in their lives by the time they hit elementary school age.

[00:44:46] RM: Yeah, absolutely. We love having teachers involved in our research, and we tried to get them involved whenever we possibly can. There are some school districts that really really limit the ability for their faculty or staff to be involved in research outside of the school. And part of the reason is that schools just get inundated with research requests from everywhere.

So, we really tried to incentivize participation from the teachers. But we ended up going into over 100 classrooms and had the support of the schools to do that, and measure classroom acoustics for the kids who were in our study. We wouldn't have been able to do that without support from the teachers and their perspectives are really interesting. Often, they're used to seeing these kids in very different listening environments than the parents, and that doesn't mean that it's more valuable than the parent’s perspective, because I still believe that parents have the best sort of impression of their child's ability to hear.

But teachers see them in social situations that are very interesting, as well as like very poor acoustics. So, on some level, the teacher’s experiences are very, very unique. And I think an important thing to characterize for kids who are spending sometimes more time in school than they are at home awake. So, I think, having that perspective is really important and I commend the teachers that collaborated with us because we wouldn't have been able to do this work without them.

[00:46:18] DS: That's really cool. My wife's a first-grade teacher, and I was like, “I don't think she's ever involved in any research before.” But at school, you guys had to establish the system to do it. I totally agree, I think it makes total sense, you have to understand what their listening is like in those environments to really get a sense of the impact of their hearing loss. So, that's, that's a really cool insight into that too. And to have so many involved, that's crazy. I mean, that's probably really helpful. But I can't imagine — again, my mind keeps going back to how much data you all have collected over these years. And I'm like, “I literally can't picture this spreadsheet, like it makes my brain hurt.”

[00:46:51] RM: It makes my brain hurt too, if that makes you feel better.

[00:46:53] DS: And you can actually see it.

[00:46:54] RM: Yes.

[00:46:55] DS: Okay. And then how about the complex listening study? Anything that particularly jumps out at you from that one?

[00:47:01] RM: Yeah, I think, so complex listening is still ongoing now. And one of the things that we're really trying to establish is why we continue to use sort of one prescriptive approach for every child. So, as I mentioned earlier, as audiologists are fond of saying, “Well, we don't expect kids who have the same audiogram to always have the same outcomes.” And yet, when we go to fit the hearing aid, we put their audiogram into the system and give specific prescriptive targets that are based on the audiogram and don't vary across individuals. So, one of the new directions that we're taking in the complex listening grant is trying to figure out what are the different factors that create individual differences in responses to hearing aids? And might there be a way for us to better customize a child's amplification characteristics to the specific type of hearing loss that they have, or to their cognitive and linguistic abilities?

So, the complex listening grant has really evolved from sort of documenting these outcomes to a more experimental phase, and we're finding some really interesting individual differences in terms of how children are using a listening strategy that differs from their peers, and how we might be able to incorporate that into amplification. I think that's just really cool, because I'm hoping it will eventually lead to the ability to sort of do a test with a child, with their hearing aid on, where you could then make modifications that would improve their perception individually, which I think would be really cool.

[00:48:37] DS: I mean, this sounds extremely interesting. I also work with cochlear implants. I'm picturing like how some researches has looked at rate changes in cochlear implant mapping per patient to see whether it's speech and noise understanding or just word recognition. When you say making changes in programming, do you mean like on like a gain level or more like on a, like sound processing level? Or what kind of changes do you mean there?

[00:49:04] RM: That analogy about cochlear implant processing is so appropriate, I think, because when you go to map a cochlear implant, you don't just take into account their NRT responses and set them with the same responses for everybody. You really do a lot of individual tuning. But with hearing aids, we don't do that. I think part of it is that in cochlear implants, you realize that there's so many variables related to how the implants interfacing with the cochlea and how the neural survival is there. There's just a lot of really great data out there on that, that we don't presently have for kids who wear hearing aids, and so some of the ideas that we have or that you can change the frequency response.

So, we're doing these experiments right now looking at what are called band importance functions, which are the sole basis of the speech intelligibility index. But if you look at an individual band importance function for a child, different kids are going to put different amounts of weighting on different frequencies. If you have a child who isn't putting a lot of weighting into a specific frequency band, just like in cochlear implants, where if you have a child who's not responding to a specific electrode, you might modify the frequency response of that hearing aid fitting in response to that piece of information.

The other thing that I think we can modify is things like amplitude compression, and compression speed, to help, if we know that children, for example, have difficulties with spectral resolution, we might not fit them with a very aggressive compression scheme that is known to distort spectral cues, for example. So, there's just I think, a lot of uncharted territory here in terms of how we might individualize amplification for kids to sort of better suit their listening needs.

[00:50:56] DS: Absolutely. I mean, I feel like it's crazy to me. I don't know if this kind of research has been done with adults, but I haven't heard of approaching hearing aids in this way before. I think it's really cool, from a cochlear implant perspective, it has always been kind of crazy to me that I can see my pediatric patient, I can run an RCD, we can do real ear and it's like, “You're good to go.” We’ll check and make sure your outcomes are going well.

But when it comes to a cochlear implant mapping, there's a billion different factors I have to include in that programming session. And I do think, hearing aids having a lot of complexity in the technology that we oftentimes don't manipulate in any way, and it's because I don't know what it would change. So, I think this research is going to be really, really cool. That's awesome that these are some of the things you're exploring.

[00:51:40] RM: Yeah, thanks. I mean, I think there are a lot of people thinking in this way about hearing aids, but like you said, it's complicated. I think cochlear implants have ended up there, essentially, by necessity, because your cochlear implant patients wouldn't use the device, if we use a very standardized approach, right? They wouldn't be able to wear it. But I think there's lots and lots of interesting things that we can do with the frequency response. And that's what the complex listening grant is really trying to dig into right now is, what can we do and what factors are important? And what factors can we just say, “We don't need to deal with that”, because sometimes knowing what doesn't affect it is just as useful for clinicians, because then you don't have to worry about doing a task, for example, that doesn't give you additional information.

[00:52:27] DS: Sure. So, is the complex listening — I'm assuming so that doesn't sound like it's the same thing as Fast Track, which is looking at mild bilateral, sensory neural hearing loss specifically?

[00:52:38] RM: Yes. So, the Fast Track project grew out of both OCHL and the OSACHH studies, because we were finding that these kids with mild bilateral hearing loss were falling way behind their peers with even greater degrees of hearing loss across the board and language, academic outcomes and a lot of different things. So, we developed Fast Track because NIH has a special funding mechanism that allows you to develop clinical tools. So, sometimes you get a research grant, and you're just asking very basic science questions. But with Fast Track, we wanted to develop tests that clinicians could use, that would allow us to better characterize mild bilateral hearing loss. So, one of the big challenges with diagnosing mild hearing loss during childhood is that when we identify these children as babies, we take these tiny insert earphones and put them in their ear canals. And those insert earphones are calibrated in a 2cc coupler, which has a much larger volume than that baby's ear canal.

So, we put the sound in there, and it's a lot louder than it is in the 2cc coupler. And what that means is that that little baby is getting a huge advantage on their hearing tests that will go away as they get older and their ear canal grows, and that coupling with that insert earphone changes. What happens with kids with mild bilateral hearing loss is they might look like they have normal hearing early on if we don't take into account their ear canal acoustics. So, the first step of the Fast Track project is to basically figure out a way to calibrate audiometric testing to the ear canal the same way that we do for otoacoustic emissions. So, we already have a method of doing this, but we just have never applied it to the hearing test side of things and Fast Track is trying to do that as well.

The other thing that when you put a microphone in the ear canal to measure the response during the test, you can also measure the child's self-generated noise level. So, we also know that kids with mild bilateral hearing loss can sometimes cover up their own thresholds by just making noise during the test and all children that we test do this. It's just sort of an intentional thing. And pediatric audiologists are well aware of it. But the problem is, when you're an audiologist, you don't really always know if the sound that you're presenting your threshold is being covered up by the noise that the child is making.

So, the other aspect of Fast Track that we're taking advantage of by having that microphone in the ear canal is to know what the noise level is in ear canal while we're testing the child's audiogram. We think both of those two things together are going to drastically improve the sort of sensitivity and diagnosis of mild bilateral hearing loss, because you're taking into account the ear canal acoustics, as well as the fact that this child might be masking their own thresholds. We think that those two things are going to hopefully improve the diagnosis of mild bilateral hearing loss and give audiologists a better sense of when a child has mild bilateral hearing loss and when they might just not be paying attention during a hearing test.

[00:55:46] DS: I mean, that's amazing. That sounds totally necessary. I've never even thought about that coupler difference when doing a test with inserts. I mean, that's crazy. I also love that you're going to have some kind of a measure for their self-noise as well. This is really cool. I'm assuming you all are in the early stages of this project, if you don't have any cool things to share with us just yet.

[00:56:11] RM: Yeah, so we have been working on Fast Track now for about 18 months. It was funded in the summer of 2020, which was like, potentially the worst time to start a research grant, during the pandemic. But I'll tell you, we spent that first year before we could start collecting data, really refining the hardware, and really trying to figure out what's something that we can do, that will be accurate, and that will — and so we spent a lot of time in software development and hardware development with our engineers that we have on the project. I think in some ways, it was really beneficial, because we didn't have a lot of opportunity to start collecting data, which we would normally be in a huge hurry to do. And it forced us to really nail down and dial in the signal processing and the hardware, and now, I think we have a better product.

So, we've been collecting data since this summer and we're excited to report that having that characterized ear canal is really important even for — we're starting this testing with four- and five-year-olds, and we're seeing big differences. So, it does seem to matter and it does seem to be clinically significant. It's always blown me away that as audiologists, we care so much about making sure that the hearing aid output in the child's ear canal isn't over amplifying them because we know that their ear canals are smaller. But we don't often extend that thinking to when we test their thresholds with inserts, even though the real ear to coupler difference for those two situations is the same.

Susan Scully and Richard Seewald published a paper 20 years ago that highlighted this problem. The only issue is we didn't have a great way to sort of correct the audiogram. And now, we have the unaided speech intelligibility index that allows us to look at not only the ear canal acoustics, but then how much are those thresholds can impact the child's access to speech, which is sort of a critical missing component.

So, just really exciting times, hoping that this will help to improve diagnosis, but we're going to actually put it to the test, because the second half of this Fast Track grant actually involves sending the tests that we've developed out into clinical settings to get tested by real audiologists. So, you can have really awesome ideas as a researcher, but if the audiologist tells us that this is a terrible idea, then we will find a different way to do it. But it's cool, because you were really going to be put to the test by the clinical partners that we have on that grant.

[00:58:50] DS: That's awesome. I'm so, so excited to see what comes out of this study. I think this is going to be just like all of the work you all have been doing. It's just like, it seems like every piece of data that's published is just like really impacting the way that we practice. I'm really grateful for your work.

I asked a previous guest who was a research audiologist this question, I'm just curious to kind of close this out here. I mean, it sounds like you get to work on projects that you're really passionate about. But if you had like an endless budget, answer this kind of research question project that you could work on, is there something out there that you're hoping one day that you could really hone in your research on? Or do you feel like you're kind of already getting there with what's happening with Fast Track?

[00:59:33] RM: Oh, no. I have lots of ideas. But if I had to put my finger on one that would be technically challenging, but would also be so worthwhile, it would be to do a research study similar to the OCHL study, but where we were able to recruit children who had additional disabilities, as well as children from linguistically diverse and underrepresented backgrounds. 

So, as you probably know, the OCHL study was awesome and it was a landmark study. But that group of kids that participated in that study were not at all like the kids that you see in your clinic. Many of the children that we see in audiology clinics have additional disabilities, many of them come from culturally and linguistically diverse backgrounds, and all of the kids in OCHL came from homes where English was the primary spoken language.

What would what I would love to do is do a study like that, but like, bring in experts in linguistic diversity in sort of neurodiversity, and really try to do the same kind of work, but looking at children from these groups that don't typically get represented in research studies. I just think if you gave me an unlimited budget, I would get in an RV and go drive around the US and meet these families where they are, and really try to look at this because I think that group is totally underserved in our research, and what that means is then clinicians who see these kids every day, have questions about how they can help them and I don't know that we're moving towards answers. I'd really like to do something like that. I think if you were going to make me pick one, that would be it.

[01:01:23] DS: That's great. I think that that's — I know that funding is not an easy process. But I think that's a really fantastic idea. And I can see that it would take a lot of professionals to complete something like that. But I think that's really valuable. Maybe there's some random Angel research investor out there listening to this right now, and they're going to have to contact you. But if not, I'm really hoping that you know that that becomes a reality one day because that would be extremely, extremely valuable research and information for clinicians in a lot of different disciplines. So, I really hope that we can make that happen for you. I want to thank you. This has been awesome. This is a dream come true to be able to interview you here. I'm curious if people wanted to reach out, if they have questions about your study or about Fast Track, or they want to get their hands on some of those resources, what's the best way to reach you?

[01:02:10] RM: So, I am all over the place on the internet. You can go to — my Twitter handle is @ryanwmccreery and I am active on Twitter. I also have a website that's just ryan-mccreery.org, that includes all of our publications and research for anyone to access. The beauty of having NIH funding is that the expectation is that we make our research available to anyone who's interested. So that's a good website. 

And then my lab has a Facebook page where we often post announcements about participating in research or the latest study that we published, and the lab is called the Audibility Perception and Cognition Laboratory or the APC lab, at Boys Town and you can find us on Facebook and hopefully stay up to date depending on whatever your preferred social media channel is. So, we haven't started into TikTok or YouTube yet.

[01:03:04] DS: It's only a matter of time.

[01:03:07] RM: I know. I'm not a good dancer. So, TikTok might be off the table. But…

[01:03:12] DS: If you guys can start disseminating your infographics into TikToks, I am there.

[01:03:17] RM: Okay. Challenge accepted. We’ll see what we can do. If it's terrible, we just won't make too many TikToks. How does that sound?

[01:03:24] DS: Yeah, there's enough content out there. It'll get lost in the shuffle. Awesome. Well, Ryan, thank you again so much for joining me. This has been great. We'd be happy to have you any time in the future. If you guys have some major new stuff to share, we'd be happy to talk again. But thank you so much again for joining me.

[01:03:38] RM: Thank you, Dakota. This has been awesome.

[END OF INTERVIEW]

[01:03:42] DS: That's all for today. Thank you so much for listening, subscribing, and rating. This podcast is part of an audio course offered for continuing education, through speech therapy PD. Check out the website if you'd like to learn more about the CEU opportunities available for this episode, as well as archived episodes. Just head to speechtherapypd.com/ear. That’s speechtherapypd.com/ear.

[END]
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