Understanding Variability in Individual Response to Hearing Aid Signal Processing in Wearable Hearing Aids.

Forty-nine older adults were enrolled, but two withdrew before fitting, five withdrew shortly after first fitting, two were excluded for insufficient wear, and five had data for only one fitting; 35 had data for both fittings. Two participants were misfit in the strong condition, so their strong-condition outcome scores were removed. The audiologist knew the fitting order, although participants and outcome experimenters were blinded. Noise reduction, feedback management, directional microphones, push buttons and volume controls were disabled, so the fittings were not typical clinical settings. The compression speed and frequency compression values were chosen to mimic laboratory signal modification ranges, not clinically typical values. The purpose was not to mimic a clinical scenario, and the trial was designed as a proof of concept rather than a clinical efficacy test. Four of 49 enrolled participants rejected the hearing aids for sound quality, a rejection rate of 8%.

The article is listed as NIH extramural supported, and the manufacturer provided an experimental version of the fitting software. No author conflict declaration is given.

Do not conclude that fast compression and frequency compression improve speech recognition in older adults. The strong setting changed the speech signal more than the mild setting, and the parameters were chosen to mimic laboratory signal modification rather than typical clinical values.