Varsha Mysore Athreya on Age Effects on Auditory Temporal Processing and it's Relationship to Speech Perception in Noise

Normally our auditory system magically hears out the voice to which we want to attend, even in a noisy cocktail party. But as we age we lose this ability, and current hearing aids don't help. What is the cause, and how can we diagnose these changes in our auditory system?

Our auditory system represents information with spikes. One spike doesn’t say very much, especially since its precise timing is rather random. But in concert with thousands of other spiking channels, we get a faithful representation of sound that lets us hear out one voice in a cacophony, and to recognize a myriad of languages. The problem is that we lose these channels and lose our ability to represent the fine time structure. This is critical for us to understand complicated audio environments

Varsha Mysore Athreya studied this issue at Purdue, recently moved to the Bay Area, and will do a better job of telling the story than I can. And she will address how these issues affect our ability to recognize speech in noise, something that is critically important to all of us.

Who: Varsha Mysore Athreya
What: Age Effects on Auditory Temporal Processing and it's Relationship to Speech Perception in Noise
When: Friday February 16th at 10:30AM
Where: CCRMA Seminar Room
Why: Representing information is critical to our perception

Come to CCRMA and we’ll discuss how we represent time, how we diagnose differences, and how this affects speech perception.


Age Effects on Auditory Temporal Processing and it's Relationship to Speech Perception in Noise

Abstract:
Individuals with normal audiometric sensitivity have variable speech perception in noise capabilities, which can worsen with age. Temporal processing plays a vital role in speech perception, especially in adverse listening conditions. Auditory decline due to aging manifests both as peripheral pathology and central auditory system changes, leading to altered temporal processing. To understand the relative contributions of these changes, we measure within-(frequency)-channel and cross-channel temporal processing in normal-hearing individuals across a wide age range. Robust perception of within-channel temporal cues requires precise coding both at peripheral and central levels of the auditory pathways. However, cross-channel processing is supported by central mechanisms. In this talk, I will present our results from a battery of behavioral and electrophysiological measures of within- and cross-channel temporal processing. Age effects on cross-channel temporal-coherence processing appear to be larger than within-channel alterations. Furthermore, our metrics of individual cross-channel temporal-coherence processing are stronger predictors of speech-in-noise outcomes, especially when tasks emphasize streaming and selective attention. Taken together, our results underscore the importance of central auditory changes in aging as a key contributor to age-related perceptual deficits.

Bio:
Varsha began her academic journey with a BS in Speech and Hearing at All India Institute of Speech and Hearing (AIISH) in Mysuru, India. In 2018, she obtained a Master’s degree in Audiology with a thesis focusing on temporal processing and speech perception in noisy environments. Her research interests stem from her master's thesis, along with six years of clinical experience and internships in government hospitals across India. In January 2020, she started her PhD with Dr. Bharadwaj, investigating age-related effects on temporal processing and its relationship to speech perception in adverse listening conditions, especially for individuals with normal audiograms. With Dr. Heinz, she is exploring the effects of peripheral hearing damage on cortical auditory responses, utilizing a novel non-invasive mini-EEG cap in chinchillas. Beyond academia, she enjoys dancing, doodling, hiking, and traveling.

These are a couple of review articles that will orient people to these research questions:

Alain, C., Dyson, B. J., & Snyder, J. S. (2006). Aging and the perceptual organization of sounds: A change of scene. Handbook of models for human aging, 759-769.

Frisina, D. R., Frisina Jr, R. D., Snell, K. B., Burkard, R., Walton, J. P., & Ison, J. R. (2001). Auditory temporal processing during aging. In Functional neurobiology of aging (pp. 565-579). Academic Press.

The novel stimulus design used in this study:

Bharadwaj, H., Mamashli, F., Khan, S., Singh, R., Joseph, R. M., Losh, A., ... & Kenet, T. (2022). Cortical signatures of auditory object binding in children with autism spectrum disorder are anomalous in concordance with behavior and diagnosis. PLoS Biology, 20(2), e3001541.