Steven Eliades, MD, PhD, Associate Professor of Head and Neck Surgery & Communication Sciences, joined Duke as faculty in 2022. We sat down with him to learn more about his research in vocal communication, and how he is getting settled in at Duke.
Q: What are the broader scientific questions that your research explores and tries to answer?
Our work broadly is looking at the processes of verbal communication. We have interests in the sensory processing side of things. How do we understand things? How does your brain process sound information and make sense of vocal communication?
We also look at the production side: how do you produce sounds and how do you use them? And a lot of our efforts are on the interface between those two. We ask questions like, how do you hear yourself when you talk? How do you process the sound of your own voice, but also how do you use that information to help you control the sound you produce?
Q: From a scientist’s perspective, then, how does our voice differ from the one we hear in our heads?
It’s a great question. The fact that everyone thinks their voicemail sounds different than how they hear themselves, or when they hear themselves on video, is important. There are two answers to that question, and they are both right to a certain degree.
The traditional answer is bone vibration. When you talk, the sound comes out your mouth, goes through the air, and comes back through your ears. At the same time, the soft tissues of your body shake very subtly, including your skull, and you can hear that. If you need proof of that, just plug your ears and talk, and you can still hear yourself reasonably well.
The other answer, though, has a lot to do with our work, which is the question of how your brain processes the sound of your own voice. It turns out that it is completely different than the way it processes every other sound that you hear.
In a sense, you are not listening to yourself, per se, you’re listening for when you deviate from the sound that you’re expected to be making. At the same time that the motor areas of your brain are sending a signal to have you make a sound, they send a separate copy of that to your auditory system that says, ‘This is what you’re supposed to sound like.’
Your auditory system, then, doesn’t just process the sound agnostically, but it asks if the sound we make is different than expected.
"We ask questions like, how do you hear yourself when you talk? How do you process the sound of your own voice, but also how do you use that information to help you control the sound you produce? "
Q: What was it that sparked an interest for you to study these aspects of communication and hearing?
It was a series of fortuitous accidents. A lot of this work started actually when I was an undergraduate, studying biomedical engineering. Originally, I was doing research with a professor who studied fluid mechanics. He ended up leaving the university, and as I was shopping around for another undergraduate research lab, it was suggested I go work with a young faculty member who was studying monkeys.
That led into this whole interest in hearing, speech, and the brain in more detail. We were doing some early basic research on the physiology of the auditory system of the animals. They put the animal in a sound booth, similar to how we test a patients’ hearing. We noticed on the video camera that every so often the animal moved its mouth, and we wondered why.
So, we put a microphone in, and lo and behold, every so often it was talking. Since we were paying attention to neurons, we saw that something funny was happening when the animal was talking, and then everything kind of followed from that.
So it was all an accident that I came across this.
As a surgeon–scientist, Dr. Eliades balances time in the clinic and time in the research lab. Learn more about Dr. Eliades’ care for patients in his Duke Health profile video.
Q: Fast forward to now, what are you working on in the lab?
We’re not quite up and running yet here at Duke, but we’re still working a lot of those same issues: the idea of self-monitoring and processing, the sound of your own voice.
One question is about this very abnormal processing activity going on in the brain. Is that activity actually necessary for your ability to control your voice? If you temporarily block it through a variety of means, do you lose some of your ability to compensate for errors you might hear?
If we put headphones on you, or on a monkey, and change the pitch of what you hear, you’ll make your voice go in the opposite direction. That’s just a reflex. The question is, if we block that brain processing, does that then block the reflect? That seems to be the case.
Q: What are the broader applications of this research?
We’re starting to ramp back up on some of the clinical and translational testing, testing patients and folks with communication disorders. There are certain communication disorders where we know that disrupting this process of listening to yourself is actually beneficial. One that we know best is for stuttering.
If you’ve seen the movie The King’s Speech, there’s a scene where the speech pathologist improved the king’s speech by making the king listen to loud music so he can’t hear himself. It’s possible that maybe you can get people to do the right thing by ignoring their hardwired reflexes.
We’re also starting to look at setting up some collaborations to extend the idea of self-monitoring to other clinical conditions. As it turns out, schizophrenia may be related to a dysfunction in the same process, and so we’re starting to talk to some folks about how can we test this explicitly.
"Monkey happens."
Q: What made you want to come to Duke to work on this research?
There were a couple of main reasons.
One is that I knew that the newly-formed department was trying to build its research portfolio, in particular to really push the clinician–scientist model, which while it had been popular at Duke and in Duke Surgery, hadn’t been a big part of Head and Neck surgery traditionally.
There’s also a lot of excellent collaborators here in neurobiology and biomedical engineering, many of whom I have actually known for many years.
Q: Do you have a funny lab story that you’d like to share?
I did have one situation where I was finishing up an experiment for the day, and I was putting a monkey back in its home, and it jumped passed my hand and ended up perching in the middle of my back where I couldn’t possibly reach it. I stood there for 15–20 seconds with a monkey between my shoulder blades not knowing what to do next, but thankfully it jumped back up to its home.
Monkeys do all sorts of the craziest things, so much so that many years ago we had t-shirts made, and all it says across it is, “Monkey Happens.”