The majority of older adults with hearing loss, which is as large as one tenth of the U.S. population, have significant difficulty understanding speech in noisy environments. The potential consequences that can stem from this speech-in-noise problem include increased social isolation, cognitive decline, and psychological disturbance. While current amplification technology has not solved the speech-in-noise problem, new interventions have the potential to improve speech recognition in noise by engaging and enhancing perceptual cues, such as dynamic pitch. Dynamic pitch, as defined by the variation of fundamental frequency, aids speech recognition in noise for older adults with hearing loss. The variability, however, is substantial across individuals. To achieve the ultimate goal of enhancing dynamic pitch and improve speech recognition in noise, it is critical to understand the variability in older individuals? benefit from dynamic pitch cues. This proposal aims to identify the perceptual factors contributing to this variability in dynamic pitch benefit among older individuals with hearing loss. The first specific aim is to establish the contribution of spectral perception to the individual variability in dynamic pitch benefit among older individuals with hearing loss. Older individuals? ability to perceive static and dynamic spectral cues will be measured. It is hypothesized that poor performance in one or both of these two tasks will significantly contribute to an older individual? inability to benefit from dynamic pitch cues in noise. The second specific aim is to determine the role of dynamic pitch glimpsing ability in dynamic pitch benefit for speech recognition in noise among older individuals with hearing loss. Older individuals? dynamic pitch glimpsing ability will be characterized using a novel metric that simulates pitch perception in continuous speech. The dynamic pitch glimpsing ability is anticipated to be a significant factor that influences individuals? dynamic pitch benefit in fluctuating noise. Drawn upon auditory scene perception theory, the third specific aim is to identify the relationship between older individuals? ability to use pitch cues for stream segregation and dynamic pitch benefit in speech maskers. It is hypothesized that individuals with poor stream segregation ability are less capable of utilizing dynamic pitch cues to separate target speech from masker and in turn, benefit less from dynamic pitch in speech recognition. Older individuals? ability to use pitch cues for stream segregation will be measured with a multi-tone pattern segregation task. This measure will be used to predict individuals? dynamic pitch benefit in speech maskers. Research outcomes will provide a better understanding of the perceptual factors that contribute to the highly variable benefit from dynamic pitch in older individuals with hearing loss. This information will serve as the foundation for the development of different pitch enhancement strategies that target specific sources of difficulty within individuals.
The cohort of older adults with hearing loss, which is as large as one tenth of the U.S. population, are chronically challenged by the difficulty of understanding speech in noisy environments. While enhancing dynamic pitch cues has the potential to improve older individuals? speech recognition in noise, it is crucial to know why benefit from dynamic pitch varies substantially across individuals. In this proposal, we will identify the perceptual factors that contribute to this variability.
