PP505 - Age-Related Changes in sTFS Cues and Their Relationship to Multi-Talker Speech Intelligibility

Posters

Location: Halls 4EF

Lead Presenter(s)

Kimberly Yurasits (she/her/hers)

Student Researcher
University of Pittsburgh
University of Pittsburgh

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.

PDF Slides

Contributor(s)

LZ

Leslie Zhen, BA

Pre-Doctoral Research Fellow
University of Pittsburgh
Pittsburgh, Pennsylvania

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
SP

Satyabrata Parida

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
JK

Jennifer Klara, BS (she/her/hers)

University of Pittsburgh
University of Pittsburgh

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Jacie R. McHaney, BS (she/her/hers)

PhD Candidate
University of Pittsburgh
University of Pittsburgh

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
VC

Victoria Cancel, MA (she/her/hers)

Graduate Student
University of Pittsburgh
Durham, North Carolina

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Maggie Zink, BS, BA (she/her/hers)

PhD Student
University of Pittsburgh
University of Pittsburgh

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Claire Mitchell (she/her/hers)

Student Researcher
University of Pittsburgh
McMurray, Pennsylvania

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Bharath Chandrasekaran, PhD

Professor and Vice Chair for Research
University of Pittsburgh

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Aravind Parthasarathy, PhD

Assistant Professor
University of Pittsburgh

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.

Abstract:
Increasing evidence suggests that a normal audiogram is not sufficient to guarantee robust communication in everyday suprathreshold listening environments. Rapidly varying temporal fine structure (sTFS) stimulus cues are critical for listening in noisy environments. Thus, the neural encoding of sTFS cues may underlie individual variability in multi-talker speech intelligibility. Here, we use a cross-species approach to study: 1) The relationship between the age-related changes in the neural encoding of sTFS cues and multi-talker speech intelligibility in humans, and 2) the contributions of age-related cochlear synapse loss to changes in the neural representation of sTFS cues in an animal model.

Summary:

Aging is associated with declines in multi-talker speech intelligibility that persist despite normal audiometric thresholds. Prior research in young adults suggests that variability in sTFS coding may underlie multi-talker speech intelligibility. However, the neural mechanisms underlying variability in sTFS coding, and the effects of age on those mechanisms remain unclear. One hitherto understudied mechanism could be degraded processing of stimulus temporal fine structure (sTFS) cues, culminating in reduced neural representations of the input speech signal. Here, we use a cross-species approach to 1) test the changes in sTFS coding with age as well as its relationship to multi-talker speech intelligibility, and 2) test the effects of age related cochlear synaptopathy on the neural coding of sTFS cues using an animal model.

Young (18-35 years) and middle-aged (40-55 years) adults with normal audiometric thresholds completed a battery of behavioral and neurophysiological assessments of sTFS processing and multi-talker speech intelligibility. This battery included behavioral frequency modulation (FM) detection to measure sTFS processing, complemented by frequency modulation following responses (FMFRs), which are phased-locked neural responses to the FM stimulus from the peripheral auditory system; and a digits-comprehension task that assessed multi-talker speech intelligibility. In parallel, FMFRs under near-identical presentation and acquisition parameters were obtained from an age-graded series of Mongolian gerbils, an animal model with comparable low-frequency hearing where sTFS processing can be measured. These measurements were paired with anatomical assessment of cochlear elements including cochlear synapses and hair cell counts.

In humans, multi-talker speech intelligibility from the digits-comprehension task, was comparable between age groups, but showed significant individual variability. However, FM detection thresholds were slightly elevated with middle-age. Additionally, FMFRs were decreased with middle-age, suggesting a loss of neural coding of sTFS cues. Ongoing analyses are aimed at examining the relationships between FMFR amplitudes and behavioral task performance. In the animal model, robust FMFRs were measured to low frequency (500Hz) tones and demonstrated a gradual decrease in amplitude with age. Immunostaining of cochlear elements also revealed a progressive loss of synapses with age. Ongoing analyses are examining the relationship between cochlear synapse loss, and reduced TFS processing with age.

Collectively, the FMFR here provides an objective measure of neural sTFS coding, which decreases with age. The indices for sTFS coding examined here can provide a novel diagnostic marker that may relate to declines in multi-talker speech intelligibility with age, despite normal audiometric thresholds.

Learning Objectives:

Upon completion, participants will be able to assess the usefulness of stimulus temporal fine structure cues in analyzing the effect age has on multi-talker speech intelligibility.