Hearing aid benefit in everyday environments.

Hearing aid benefit was measured for three matched groups of eleven hearing-impaired subjects, each serving in one typical listening environment. Benefit was quantified in terms of improvement in intelligibility score for the Connected Speech Test. Each subject was individually fitted with three hearing aids, differing in nominal frequency response slope by a total of 8 dB/octave. Research questions centered on the amount of benefit typically realized in everyday environments and the interactions of this benefit with frequency response and/or visual cues. Results revealed: (1) mean benefit in a living-room type setting was about 24% and significantly greater than in a reverberant setting (7%) and a noisy setting (-1%); (2) despite the relatively large mean difference in benefit between the reverberant and noisy environments, the difference was not statistically significant (p greater than 0.05); (3) the addition of visual cues did not change hearing aid benefit in any tested environment; (4) there was no significant overall trend for any of the three different frequency-response slopes to give superior benefit in any environment; (5) 76% of the subjects achieved significantly different benefit (p less than 0.05) in at least one hearing aid condition when data were considered on an individual basis; and (6) articulation indices in the aided conditions did not successfully predict the observed within-subject benefit differences. Benefit was significantly related to speech reception threshold in the living-room environment. However, in the less favorable environments, benefit and hearing loss were not related despite the fact that benefit varied considerably across subjects.