Understanding Individual Differences in Acoustic-Phonetic and Contextual Cue Use In Aging - Project Summary/Abstract
Age-related hearing loss (ARHL) affects a large number of older adults (~50% of adults aged 75+), yet not all
individuals are equally impacted. Understanding why some older adults struggle more with ARHL is an
important first step in designing more effective treatment plans. This proposal explores the hypothesis that
individual differences in the use of contextual vs. acoustic-phonetic cues explains variation in speech
comprehension abilities beyond just hearing ability. Natural listening environments contain a variety of cues
that listeners can rely on to aid in speech comprehension. Despite the availability of many cues, recent work
with healthy younger adults and older adults (including pilot work for this proposal) has demonstrated that
some individuals tend to rely more on higher-level contextual information and others rely more on lower-level
acoustic-phonetic information to interpret ambiguities in speech. The goal of this project is to test the
hypothesis that these individual patterns of cue use will explain differences in speech comprehension (Aim 1)
and to examine at what point in processing these individual differences arise using neural data collected from
electroencephalography (EEG; Aim 2). One two-session experiment will be run testing younger and older
adults on an audiometry battery, a cognitive battery, a cue use task in which they listen to sentences that
contain ambiguous words, and a passive storybook listening task. EEG will be recorded during the cue use
task and the storybook listening. While controlling for hearing and cognitive abilities, the contribution of an
individual’s cue use will be tested in a model predicting speech comprehension (Aim 1). Neural data will then
be analyzed to test three potential mechanisms that could lead to behavioral differences in cue use: (1)
differences in early perceptual encoding of ambiguities in speech, (2) differences in later repair processes, and
(3) differences in overall predictive mechanisms. A combination of event-related potential (ERP) and temporal
response function (TRF) analyses will be performed to identify the locus of individual differences. Overall, this
proposal provides important insight into different profiles of ARHL, and insights from neural data will highlight
where in processing differences arise, potentially serving as a basis for designing effective treatments.
Additionally, studying patterns of cue use may potentially reveal individuals whose ARHL may initially go
undetected (those who tend to rely more on contextual cues). This proposal will prepare the applicant to lead
an independent line of work examining the neurobiology of speech comprehension from an individual
differences lens. Specifically, this proposal will give the applicant opportunities to engage with clinicians,
expand individual differences work in cue use into older adults, and gain expertise in multiple computationally
intensive analysis methods of EEG data.
