Differential sensitivity to tonal frequency and to the rate of modulation of broad-band noise by hearing-impaired listeners

This dissertation examined whether a hearing impairment of the auditory end-organ has the same or a differential effect on the place and periodicity processes. Differential sensitivities for four normally hearing listeners and for both ears of five patients with unilateral Meniere’s disease were measured for tonal frequency and rate of sinusoidally amplitude-modulated noise at common frequencies and rates of the stimulus.

Frequency responses of hearing aids and their effects on the speech perception of eight hard-of-hearing subjects

This dissertation examines the relationship between frequency response and word-discrimination performance of hearing-impaired persons. Three questions are addressed: does the restoration of the normal field-to-eardrum transfer function improve word discrimination; is the restoration of the normal shape of the audibility curve (uniform hearing level at all frequencies) beneficial to hearing-impaired listeners; and can speech discrimination be improved by an extension of the present narrow-band response in hearing aids.