Background: Despite the recognition that the directional microphone hearing aid (DMHA) is an
important intervention aimed at helping older hearing-impaired adults understand speech
in noisy environments, there is little evidence that older listeners can actually
benefit from directional processing.
Purpose: The objective of this study was to determine if older and younger adults can obtain
and perceive comparable benefit afforded by DMHAs.
Study Sample: Twenty-four hearing-impaired adults aged 36 through 79 yr were fit with switchable-microphone
hearing aids and tested in the laboratory and the field.
Data Collection and Analysis: In the laboratory, the listeners’ directional benefit and preferences for microphone
modes (directional vs. omnidirectional) were assessed using various speech-recognition-in-noise
tests. In the four-week field trial, a paired-comparison technique and paper-and-pencil
journals were used to determine the benefit provided by directional processing. The
effects of age on directional benefit/preference were analyzed using generalized linear
models with controlling for the effect of hearing loss.
Results: The results revealed that age did not have a significant effect on directional benefit
and preference as measured in the laboratory. However, the field data showed that
older age was significantly associated with a lower preference for the directional
mode.
Conclusion: These results indicate that although listeners of different ages may obtain and perceive
comparable benefit from DMHAs in laboratory testing, older users tend to perceive
less benefit than do younger users in the real world. The implications of these findings
are discussed.
Key Words
Aging - directional - hearing aids
