How Audiologists are Detecting Hearing Loss in Children Through Audiobooks
Melissa Polonenko (PhD) is an assistant professor in the Department of Speech-Language-Hearing Sciences. She runs the PoloLab, where they investigate new ways to assess hearing and vestibular ability to better support those with communication difficulties. This goal is translated into her current research, which aims to streamline hearing loss assessment processes for children or those who are unable to effectively communicate their experience in typical diagnostic assessments.
What brought you to UMN? What is your role here?
I came to UMN to join the Department of Speech-Language-Hearing Sciences as an assistant professor. Within this role I run a lab, teach courses related to hearing and balance, and perform service commitments to the department, college, university and my broader field.
My current research program improves diagnostic assessment of hearing loss, especially in children. The specific innovations from my lab tackle notorious and long-standing challenges in clinical audiology relating to the challenge of providing a thorough assessment within a limited time. At UMN I have the opportunity to mentor undergraduate, audiology professional doctoral, and research PhD doctoral students in my lab. They bring a richness of perspectives that is refreshing and exciting to work with.
My combined clinical and research background both lay the foundation for my teaching. I’ve taught the introductory audiology assessment course for the undergraduates, but most of my teaching experience is within the audiology doctoral program. Currently I regularly teach the courses on electrophysiology assessment, vestibular and balance assessment, pediatric assessment and childhood hearing disorders courses. I’m also very active in coordinating the audiology doctoral capstone projects.
I came to UMN because of its rich environment for growth on many levels. I already knew of some of the amazing hearing scientists that are here, but also learned about how collaborative people are and the many resources available to support our professional development. I also appreciate the array of questions that my colleagues each tackle in their research, which gives me a broader perspective of our work in communication.
On a personal level, I love the four seasons in Minnesota, including the winters! I’m Canadian and have lived in colder places and knew that I could thrive here. As a hockey fan, Minnesota is the place to be – and I love that we have an amazing women’s hockey team at UMN, as well as one of the first pro-hockey women’s teams.
How would you describe your current work?
My current work is assessing hearing function through neural responses to engaging stories.
This project is advancing our work in developing a neural test of hearing function using engaging stories — a stimulus that a child would be more engaged with and listen to for a long enough time to collect sufficient data, when compared to other sounds like syllables or brief tones. We are investigating what the optimal parameters are so that we can make the test as efficient yet accurate as possible.
This fits with my broader research, which involves creating innovative translational methods to assess hearing function in populations who cannot give a behavioral response about what they hear, including infants, young children, and those with developmental and behavioral conditions.
Creating these tools is critical to ensuring hearing difficulty is identified early, and timely decisions are made that impact the child’s developmental trajectory. They also enable a way to validate the treatments we provide (such as hearing aids) to young children — something that is lacking in our clinical repertoire. Currently, we must wait until the children are old enough to talk and perform complex behavioral tasks. My research bridges these testing time and population gaps by providing tests that can be done at any age and require minimal responses from the child, while providing key information about how the brain receives speech for language acquisition.
What does your research look like? What about your methods?
We use a few different methods in our lab. First, we collect behavioral responses from people by having them raise their hand, click a button or say their response to the different sounds we present to them.
Secondly, we use computational modeling to predict what our neural responses will look like to the audiobooks and other sounds we plan to use in an experiment, so that we can be more selective in the choices we make during our experiments.
Lastly, and most frequently, we use electroencephalography (EEG) to study the auditory system. This involves placing sensors (either stickers or small “donut hole”-like rings) on the surface of the head and on the earlobes, which pick up the naturally-occurring electrical activity that you are making in response to sound (your neural activity). We focus on the change in activity in response to the different sounds we play.
In this project we play audiobooks either on their own (“in quiet”) or in different listening conditions, like when you are listening to someone but there are others talking in the background. This will help us understand the mechanisms of how the auditory system processes speech in different listening conditions and whether this can be used as a biomarker, [like a check engine light would be in a car] for hearing dysfunction in folks who cannot tell us what they hear.
How did you become interested in your topic?
I worked for years as a pediatric audiologist before going back to do my PhD in neuroscience. I saw first-hand how we had some good tools but were limited in our ability to evaluate how well our young patients were doing, or those patients who had additional challenges that made it difficult for them to complete the behavioral testing to evaluate how they hear or how they are doing with the devices we gave them to hear.
For example, we could ensure we were fitting their hearing aids well, but didn’t really know how their brain was registering the sound while they were developing enough to talk and perform the behavioral testing that would allow us to know how much it was supporting their speech and language acquisition.
It was clear that some children struggled more than others, and caregivers would express how tired the school-aged children would be after a day of school and listening. I wanted to better understand auditory development in the context of more naturalistic stimuli, something that our clinical assessments were limited in their ability to do. That started me on a journey that keeps going, as there are always new questions to ask.
What’s next for you?
We’ve optimized the parameters to make the test more efficient, and evaluated different narrator characteristics to allow us to use a wide variety of audiobooks in our testing so that it’s more engaging to different people. There are so many questions that we can tackle.
Now we’re using this method to study how the auditory system encodes speech in the difficult listening environment of having background noise. Listening to someone speak (like an audiobook) while there is background noise is really difficult for many people, whether they have normal hearing sensitivity or a hearing loss.
Currently my students are conducting a study to see how your brain encodes speech when the difficulty and type of noise changes — when you are listening to a talker but there are two, four or even 12 different people talking at the same time (like in a coffee shop, for example), or if it’s just background noise (like a sleep machine). We also vary how loud those other talkers or noises are compared to the story you’re trying to listen to, making the listening more or less difficult.
We are also planning to extend this study to determine if how your brain responds differently to an audiobook in quiet or in background noise can predict your level of difficulty understanding speech in noise, and if this can be used as a “neural” screener of hearing difficulties for people who cannot do behavioral testing.
As a pilot study, we are partnering with the Center for Applied and Translational Sensory Science (CATSS), which now has a research/health mobile unit (bus) that we will take to the county and state fairs. We are interested to understand how the brain’s processing of speech in these different listening contexts changes across age, and this will be a pilot project to determine feasibility.
This story was edited by Rory Schaefer, an undergraduate student in CLA.
