U of A researcher finds meaning helping people hear

Bill Hodgetts uses algorithms and AI to provide individualized treatment to patients with hearing loss who wear bone conduction devices.

Shirley Wilfong-Pritchard - 3 April 2024

Bill Hodgetts is a professor in the University of Alberta’s Faculty of Rehabilitation Medicine, Department of Communication Sciences and Disorders. He holds a joint appointment at the Institute for Reconstructive Sciences in Medicine (iRSM) at the Misericordia Hospital where he is the program director for audiology and bone-conduction amplification — the largest bone-conduction hearing program in Canada and one of the largest in the world. He also leads the Bone Conduction Amplification Laboratory, located at both the U of A and iRSM.

Hodgetts earned a BA in psychology and an MSc in audiology from the University of Western Ontario and a PhD in rehabilitation sciences from the U of A.

We caught up with Hodgetts to learn more about him and his research.

What is your area of research and why is it important?

My primary area of research involves treatment for people who cannot wear regular hearing aids or cochlear implants. For those who have chronic ear problems or infections or are born without an ear canal and can’t fit a hearing aid in their ear, we can insert a small titanium screw at the back of their head where we attach a hearing aid. Eventually the titanium and bone grow together. By connecting a bone conduction device to this implant, it bypasses the problem with the outer or middle ear and sends the signal directly to the inner ear so they can hear.

At the Bone Conduction Amplification Lab, we contributed to the development of a tool called a skull simulator that allows us to measure the amplification output of a hearing device. To determine the best output for each user, we collaborated with the University of Western Ontario to convert an air-conduction prescriptive algorithm (which is used to find the best output for people with air-conduction hearing aids) into a bone-conduction prescriptive algorithm for our clients.

We’ve been validating that prescription and using it clinically for the last five years and it’s working well. Most manufacturers of bone-conduction devices use our prescriptive algorithm and pay an ongoing licensing fee that helps fund our continued research. 

While the vast majority of our clients are hearing well and have no skin concerns, a few might develop a slight issue where their implant sticks out. In response, we’ve been working on training an algorithm using AI so that ultimately we will have a phone app where you just take a picture of the skin around the implant and the app will tell you whether that implant is “green” meaning no problems, “yellow” meaning keep an eye on it, or “red” meaning go see your doctor. This will minimize visits to ENT (ears, nose and throat) doctors and help clinicians and patients in remote locations make decisions without having to drive to a major centre.

For implants under the skin, we’re also developing a prototype for a really sensitive microphone that sits on the patient’s forehead while their hearing device is vibrating, allowing us to measure the output of that device. Children under the age of five are too young for a surgical implant because their skulls are still small and soft. Instead, we use an elastic headband to connect the device so they don’t miss out on those important years of language development. The prototype will allow us to measure them as well, conceivably. The prescription and verification will tell us output measurements that a baby can’t.

Another tool we have started to use in the lab is pupillometry. It can be used to gauge your interest, or effort while doing listening tasks. In this experiment, we’re tracking people’s pupils to see what happens when they miss hearing a word in a sentence and then have to use cognitive effort to figure it out. Our experimental hypothesis is that the better hearing you’re getting with our algorithm compared to other algorithms will lead to less cognitive effort, which will lead to lower pupil dilation. 

This will reveal a lot about the complaints we hear from people with hearing loss — that life with hearing loss can be exhausting and it’s often too much work to go out and have a conversation with friends anymore. And it will enlighten us about the influence of a well-fitted hearing aid.

What is the most rewarding aspect of your work?

Seeing patients in the clinic reminds me that we’re doing a good job, the algorithms are working and the research we’re investing our time in is beneficial to patients. But the best thing for me is when we have new clients come in and I put a demo device on their skull so they can hear by bone conduction for the first time. The life altering that happens in that moment! People often become very emotional because they realize that for all these years they’ve been missing so much and that there is hope for better hearing and communication. 

On the university side of my job, I love how research gives me the opportunity to shape, direct and guide students. 

What do you find the most challenging?

Trying to navigate research within a health-care context is really a struggle at times. There are more administrative steps and approvals than there are in a straight academic context and this can sometimes get in the way of doing the good work. That’s a frustration when all you really want to do is help the person in front of you.

What’s something your students or colleagues might be surprised to learn about you?

I took up hand-tool woodworking during the pandemic and I love it. I probably have bored all the students with this by now. 

What’s the No. 1 piece of advice you give your graduate students?

Uncertainty will follow you throughout an academic degree — grants, paper rejections, too much negative feedback or your experiment didn’t work out. But you learned from it. Become comfortable with uncertainty and trust yourself.