Effects of Hearing Aid Amplification on the Ability of Individuals With Hearing Loss to Perceive Spectral Information

Individuals with sensorineural hearing loss often struggle to understand speech even with the use of hearing aids; simply making sounds louder is not enough. Listeners decode various speech sounds with the help of spectral information, but how hearing aid amplification affects individuals’ ability to perceive those cues is not currently well understood. Altering the way hearing aids are programmed to provide amplification can potentially improve the ability of listeners with sensorineural hearing loss to access spectral information. The purpose of this study was to quantify the effects that hearing aid amplification has on the perception of spectral cues. Outcomes could help clinicians select hearing aid prescriptions that improve the adult listener’s ability to perceive spectral cues in speech. Participants with sensorineural hearing loss (normal middle ear function) were tested in aided conditions including alteration of compression channels (4, 8, and 16). Psychophysical tuning curves were collected from each participant, with a target frequency of 2 kHz and a presentation level of 10 dB SL in reference to a threshold obtained in quiet conditions. Data were compared to psychophysical tuning curves collected from participants with normal hearing. We hypothesized that the 16-channel condition would produce psychophysical tuning curves that matched the normal hearing individuals’ psychophysical tuning curves most accurately; an increased number of compression channels would provide better audibility across all frequencies, thereby improving access to spectral information. Indeed, as the number of compression channels was increased, the low-frequency side of the psychophysical tuning curves showed improvement