Approximately 36 million Americans report having some degree of hearing impairment. Hearing loss is associated with social isolation, depression, cognitive decline, and economic cost due to reduced work productivity. Understanding ways to optimize communication in listeners with hearing impairment is therefore a critical challenge for speech perception researchers. A hallmark of recent research has been the development of the concept of listening effort, which emphasizes the importance of cognitive processing during speech perception: Listeners with hearing impairment can often understand spoken language, but with increased cognitive effort, taking resources away from other processes such as attention and memory. Unfortunately, the specific cognitive processes that play a role in effortful listening remain poorly understood. The goal of the current research is to provide a more specific account of the neural and cognitive systems involved in effortful listening, and investigate how these factors affect speech comprehension. The studies are designed around a framework of lexical competition, which refers to how listeners select a correct target word from among the possible words they may have heard (Was that word cap or cat?). Lexical competition is influenced by properties of single words (words that sound similar to many others, like cat, are more difficult to process), the acoustic signal (poorer acoustic clarity makes correct identification more difficult), and individual differences in cognitive processing (lower inhibitory ability makes incorrect targets more likely to be perceived). Neuroanatomically, these processes are supported by dissociable regions of temporal and frontal cortex, consistent with a large-scale cortical network that supports speech comprehension. Importantly, individual differences in both hearing impairment and cognitive ability interact with the type of speech being processed to determine the level of success a listener will have in understanding speech. The current research will involve collecting measures of hearing and cognition in all participants to investigate how individual differences in these measures impact speech perception. Converging evidence from behavioral studies, eyetracking, and functional magnetic resonance imaging (fMRI) will be used to explore the cognitive and neural basis of speech perception.
Aim 1 evaluates the relationship between lexical competition and listening effort during speech perception.
Aim 2 characterizes multiple cognitive processes involved in processing degraded speech.
Aim 3 assesses how individual differences in hearing and cognition predict speech perception, relying on a framework of lexical competition to inform theoretical interpretation. These studies will show a relationship between lexical competition and the cognitive processes engaged when processing degraded speech, providing a theoretically-motivated framework to better explain the challenges faced by both normal-hearing and hearing-impaired listeners.

Public Health Relevance

Hearing impaired listeners are often able to successfully understand spoken language, despite the reduced quality of the acoustic signal, through increased perceptual effort. However, this increased effort comes at a cognitive cost that can interfere with other processes, such as attention and memory. The current studies use a combination of behavioral and brain-imaging techniques to explore the neural systems supporting speech perception in challenging listening situations, the results of which will help us to better understand and treat speech comprehension difficulty in people with hearing impairment.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC014281-02
Application #
9103070
Study Section
Language and Communication Study Section (LCOM)
Program Officer
Donahue, Amy
Project Start
2015-07-01
Project End
2020-06-30
Budget Start
2016-07-01
Budget End
2017-06-30
Support Year
2
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Washington University
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Peelle, Jonathan E (2017) Listening Effort: How the Cognitive Consequences of Acoustic Challenge Are Reflected in Brain and Behavior. Ear Hear :
Peelle, Jonathan E; Wingfield, Arthur (2016) The Neural Consequences of Age-Related Hearing Loss. Trends Neurosci 39:486-97