Threshold Improvement and Acoustic Gain with Hearing Aids

Abstract

Aided speech reception thresholds were obtained from 20 hearing-impaired listeners with three hearing aids adjusted to comfort settings, and with the aids adjusted to deliver 40 dB of acoustic gain. The aided speech reception threshold under each condition was subtracted from the unaided speech reception threshold to yield a measure of threshold improvement. Threshold improvement and acoustic gain comparisons revealed that, at comfort settings, these two measures were quite similar. However, at the 40-dB gain setting, acoustic gain exceeded threshold improvement by an average of 5.6 dB. For the high-gain condition, it appeared that the threshold improvement obtained by subjects with relatively good unaided sensitivity was limited by the ambient noise in the test chamber

Key Words:

• Hearing aids
• Unaided speech reception threshold
• Aided speech reception threshold
• Acoustic gain
• Threshold improvement