The Brain-Behavior Relationship: Age, Hearing, and Their Effects on Understanding Speech in Noise

Project Summary Approximately 37.5 million Americans have some problem hearing, and one of the chiefcomplaints of those with hearing impairment is difficulty communicating in background noise. Inaddition, many older individuals have difficulties understanding speech in background noisebeyond what would be expected based solely on their audiometric thresholds. There is afundamental need for improved diagnosis and treatment of speech understanding in noisedifficulties. This research program sets out to establish electrophysiological correlates ofspeech-in-noise understanding with the goal of supplementing speech-in-noise testing. Theassumption is that accurate perception in noise is dependent, in part, on the accuracy of neuralcoding of the auditory stimulus. By combining electrophysiological and behavioral informationwe can advance our understanding of perception-in-noise difficulties and predict outcomes indifficult-to-test individuals using physiological testing. The clinical significance of the research proposed is related directly to the ability topredict, more accurately diagnose, and more precisely treat perception-in-noise difficulties. Anelectrophysiological measure that predicts speech perception will allow for improvedassessment of difficult-to-test populations and provide information about the capacity of thatauditory system to encode certain stimuli. This will allow the clinician to tailor treatmentstrategies to the specific needs of the individual and to counsel patients more effectively interms of the expectations they should have and the benefit they should expect as a result ofspecific treatments. Therefore, to further our understanding of signal-in-noise perception andneural coding, we will use brainstem, cortical, and cognitive auditory evoked potentials andbehavioral speech understanding-in-noise measures with age and hearing impairment ascontinuous variables to characterize the effect sizes of various covariates and to improve ourunderstanding of the relationship between brain and behavioral measures.