CENTRAL FACTORS IN AUDITORY MASKING

点击翻译按钮获取中文摘要

The goal of this work is to gain a better understanding of the role of central factors in auditory masking in listeners with cochlear hearing loss. The work has theoretical significance for the study and remediation of hearing impairment by aiming to better understand the causes of the communication difficulties experienced by listeners with cochlear hearing loss. The proposal is based on a theory that identifies two types of masking that occur at different physiological levels. Peripheral or "energetic" masking occurs because of overlapping patterns of excitation in the cochlea and has been studied in detail for many years. Central or "informational" masking involves cognitive processes related to the perceptual organization of sound images and the analysis of sound patterns. Informational masking is not well understood, and occurs despite a robust representation of the signal in the auditory periphery. The purpose of this study is to extend the work on informational masking to listeners with hearing loss. This knowledge is critical because of the prevalence of auditory pathologies affecting the sensory mechanism and the extreme difficulty in communication such pathologies often cause, particularly in noisy listening conditions. Although it is clear that sensory pathology affects the spectral and temporal analyses performed at the periphery, there appears to be a significant component to masking that cannot be attributed purely to peripheral deficits. The plan is to test the hypothesis that listeners with sensorineural hearing loss experience abnormally large amounts of informational masking in certain conditions and make poor use of the cues that normally reduce informational masking. This hypothesis will be examined through a series of psychoacoustic experiments employing listeners with cochlear hearing loss. The goal is to relate the amount of informational masking to factors such as etiology and configuration of loss, auditory filter characteristics and processing efficiency, age and speech recognition in noise.