Transcript
VINCE LARA: Hi, and welcome to another edition of A Few Minutes With, the podcast that showcases Illinois College of Applied Health Sciences. I’m Vince Lara, and today I’m speaking with Justin Aronoff, an assistant professor in the Department of Speech and Hearing Science, about his research on the binaural auditory system as it relates to cochlear implants.
All right, Dr. Aronoff, thank you for joining me on this edition of the podcast. And commonly, I ask guests of the podcast about their inspirations for their research. So what made you look into auditory research? And you do primarily cochlear implants. So what made you look into that kind of research?
JUSTIN ARONOFF: So I kind of fell into this area. I was actually– I was having a bad experience at a postdoc. And there was another research position at the institute that I was at. And it was a hearing aid lab, primarily, that happened to have one cochlear implant project.
And I ended up on that project. So it’s a complete chance I ended up working a cochlear implant users at all. And I just fell in love with this field. I fell in love with the work. And it’s so rewarding to work with cochlear implant users.
One of the unique things about working with this patient population is that you tend to be individuals who come back to lab, you know, sometimes month after month for years. We’ll see them, and so we build up these relationships. It becomes very rewarding.
And it’s also a population that really values the research. So we do what is not necessarily the most exciting experiments to be in. We have people listen to beeps for five hours sometimes, which sounds very thrilling, I know. And I do sometimes ask them, look, I really appreciate that you’re coming in here and doing these incredibly boring experiments. I got to ask why, though. I appreciate it, but why are you doing it?
And what they often respond is they say, well, you know, I realize that what this device has done for me is a miracle. And I realize that the reason that it does what it does for me is because 20 years ago, there was someone sitting in a chair like this, listening to beeps for hours on end. And I really want to pay it forward. I really want to give to the next generation. And that type of sentiment is really kind of motivating to me, kept me really interested in continuing and working in this field.
VINCE LARA: Yeah, you kind of answered my next question, but I’ll ask it anyway. So you did your undergrad work in teaching, in the teaching of Spanish.
JUSTIN ARONOFF: Yes.
VINCE LARA: So then you followed with a masters in linguistics, which makes sense, right? You had these two– you had a pattern here. And then that led to Speech and Hearing Science. And that’s primarily because of how you felt about the population within that demographic, if you will?
JUSTIN ARONOFF: Well, I didn’t find cochlear implants until my postdoc.
VINCE LARA: OK.
JUSTIN ARONOFF: So my path was definitely fortuitous, to say the least. So when I was an undergrad here at U of I, in teaching Spanish, I did study abroad in Spain. And I took a linguistics course. And that got me very interested in linguistics.
And when I came back to campus, the only linguistics course that fit into my schedule was a neurolinguistic course by Molly Mack. And that really got me interested in the brain, and language, language acquisition. And so I went on and did my master’s in linguistics.
I was actually in the PhD program in linguistics at the University of Southern California. And as I got more and more interested into the neuro side of it, it felt like it didn’t quite fit into just the narrow range of neurologistics. I was interested in broader issues in neuroscience. And so I actually changed over into the neuroscience program to finish up my PhD.
And as I was doing that, I had the naive idea that, hey the auditory system seems like a fairly easy system to work with and to understand. But I was definitely a little naive at the time. And so that got me interested in working auditory work, and led to working at the House Ear Institute, and then eventually into doing postdoc there.
VINCE LARA: Mmhmm, now, Dr. Aronoff, for you listeners, recently received a seven-figure grant for a project that examines how the binary– binaural auditory system works. And so I’m curious, so the binaural system, for those of you who are uninitiated in this, is how the brain combines signals from our two ears. But I’m curious, why is that important?
JUSTIN ARONOFF: So having the ability to combine information from two ears can help in a lot of different situations. One of the big benefits is noisy environments. So typically, when you’re in a noisy environment– let’s say you’re at a restaurant– you’ve got the person you’re listening to is right in front of you but you’ve got all this background noise. You might have a table to side where those people are talking, you’re trying to tune them out.
The ability to basically attend to and separate out these spatially distinct sources of sound is dependent on the fact that you have two ears and that you can combine that information so it allows you to better focus on the person that you want to attend to, depending on wherever they are in space.
It’s also really important for localizing. So when you only have one ear, you really can’t tell if a sound is coming from the left or the right, especially if you don’t know what the volume is. There are some tricks you can use. But in general, most people are just very, very bad at being able to even tell the side that a sound is on when they only have one ear. Having two ears allows you to localize where the sound is.
You know, and also, patients also describe that having two ears makes the world seem fuller. It’s just this kind of qualitative sense to the world with two ears that you also don’t get having one ear alone.
VINCE LARA: Hmm. Your research is primarily focused on the importance of the study relative to cochlear implants. And–
JUSTIN ARONOFF: Yeah.
VINCE LARA: –the study states that you plan to maximize binaural benefits. And I wonder how you propose to do that.
JUSTIN ARONOFF: So one of the things that we found, my lab and other labs in this field, is that one of the big detriments in terms of getting those benefits from having two ears is when the information that you’re getting from the left and the right ear are mismatched.
And this can happen in a number of different ways. But the way that we see it happening with cochlear implants has to do with where the cochlear implant array is sitting, within the left or right cochlear, within the left and right ear, as well as what neurons are actually surviving in those two ears.
So it turns out that if you do not stimulate the same places, the same relative neurons in the left or the right ear, your ability to localize or ability to use these binaural cues and these cues that you get from having two ears decreases quite a lot.
Now, we know that there are potentially some mechanisms that can help you with that. There’s some ability to adapt. And our lab and other labs have looked at the ability to adapt to this mismatch between the two ears. It’s not clear how limited that is. We know you can do it in terms of the perception of what sounds like the same pitch in the two ears. Whether or not that translates to other things or not is not clear yet.
And really, what we’re trying to understand is how does that adaptation affect your ability? How do we need to change how we program these devices? When do we need to change? So if adaptation can handle a lot, maybe we can wait. If adaptation cannot handle a lot, then we need to start reprogramming very early on when you first get these devices.
And so we’re trying to look at kind of how do you manipulate where the stimulation is, how do you manipulate how similar the stimulation is in the two ears in order to improve those binaural benefits.
VINCE LARA: You helped develop a test that measures spectral resolution. And I’m wondering– two questions– what’s spectral resolution? And what’s the test?
JUSTIN ARONOFF: So spectral resolution is basically your ability to tell that two notes that you’re playing on the piano are not the same note. So people who have poor spectral resolution basically are not going to be able to tell that two notes that are roughly two notes apart are actually not the same note. And this is a common problem that we see with cochlear implant users.
And the reason that this is important is because it turns out that your ability to understand speech in a noisy environment really relates, in part, to your spectral resolution. And that’s something that we know that is a problem for cochlear implant users, as well as other patient populations.
So this is a test that I co-developed with David Landsberger when we were both at the House Ear Institute. And basically, this is a spectral-temporally modulated ripple test, or the SMRT. We’ve since modified it to create a version that can be used in the clinics as well, that’s the SMRT Lite for computeRless Measurement or SLRM. And basically what these measures are, they sound a lot like 1980s arcade sounds.
VINCE LARA: Hmm.
JUSTIN ARONOFF: And basically, it’s a fairly easy test. You just need to tell which sound is different, all right? And so you’ll hear three sounds that kind of sound– it’s kind of Space Invaders-y sound. And you’re trying to tell what’s [? different. ?] We’re manipulating, and there is some of the spectral properties, basically how close together these little ripples that we have across the spectrum, how close together they are and whether you can tell that one of them is closer than the other two.
VINCE LARA: Hmm.
JUSTIN ARONOFF: So it’s a fairly easy test for people to do. We’re not asking them to do anything but tell which one is different. And what’s nice about it is it turns out that it correlates well with speech perception in quiet as well as in noise. We’ve found that other labs around the world have found that as well.
So it turns out to be a nice kind of proxy test. Why the clinics have gotten interested in this is because one of the big problems that a lot of clinics have– I work with UIC in Chicago, for instance– is that they’ll often have patient populations that speak a wide range of languages, where English is not the native language. And when English is not your native language, testing someone on speech perception in English can be problematic because you don’t know if the problem is an auditory problem or if it’s a language problem.
VINCE LARA: Mmhmm.
JUSTIN ARONOFF: And so what’s nice about this test is that it’s a non-linguistic test. It doesn’t depend on languages. These are, like I said, kind of arcade-type sounds. There’s no linguistic content. But it does predict language performance.
VINCE LARA: Using your master’s in linguistics there, I would imagine.
JUSTIN ARONOFF: Yeah.
VINCE LARA: Yes. You know, you’re at an R1 university. And with that, your time is often dominated by research here at the University of Illinois. But teaching is a part of your responsibilities as well. And so I’m wondering what’s your favorite course to teach?
JUSTIN ARONOFF: That is a hard question. It’s hard to choose one, for sure. I really do enjoy teaching. And obviously, I got my degree in teaching. And I’m a licensed teacher in the state of Illinois. I come from a family of teachers. So it’s something I’m very passionate about.
If pressed, I would have to say it’s probably SHS280, Communication Neuroscience. It’s something that’s in that area where I got my PhD. I’m definitely very passionate about neuroscience. I really liked the large undergrad classes. I like those classes where this might be their first exposure to the area and you can really see the growth and the coming in really knowing next to nothing about the topic area, and then leaving. You can see kind of the growth of balance that they come out with.
So it’s a really rewarding class. And it’s just a fun class.
VINCE LARA: My thanks to Justin Aronoff. For more podcasts on Illinois College of Applied Health Sciences, search A Few Minutes With on iTunes, Spotify, iHeart Radio, radio.com, and other places you get your podcasts fix Thanks for listening, and see you next time.
