Self-Fitting Hearing Aids: Effects of Starting Response and Field Experience

To determine the effects of changing from a prescribed to a generic starting response on self-fitting outcome and behavior before and after a brief field experience.

Twenty adult hearing-aid users with mild-to-moderate hearing loss used a smartphone interface to adjust level and spectral tilt of the output of a wearable master hearing aid while listening to prerecorded speech, presented at 65 dB SPL, in quiet. A prescribed starting response was based on the participant's own audiogram. A generic starting response was based on an audiogram for a typical mild-to-moderate hearing loss and was the same for all participants. Initial self-fittings from the two starting responses took place in the lab. After a brief field experience, involving conversation, self-hearing, and ambient noise, with readjustment as needed, self-fittings from the two starting responses were repeated in the lab. Starting responses, self-fitted responses, and adjustment steps were logged in the master hearing aid for subsequent evaluation of real-ear output spectra and for assessment of self-fitting behavior.

Neither starting response nor field experience had a significant effect on mean self-fitted output in the lab ( p = 0.506 and 0.149, respectively). However, the SD of individual starting-response effects on high-frequency self-fitted output fell by around 50% after the field experience ( p = 0.006). The effect of starting response on self-fitting behavior was limited to number of adjustment steps, which was higher for the generic start ( p = 0.014). The effect of field experience on self-fitting behavior was limited to a 50% reduction in self-fitting time ( p < 0.001). This reduction was attributable mainly to less time spent listening after each adjustment step ( p = 0.019).

The findings support the conclusion that, for a population with mild-to-moderate hearing loss, a generic starting response can be a viable option for over-the-counter self-fitting hearing aids. They highlight, however, the need for practice and experience with novel self-fitting hearing aids and the fact that self-fitting may not be suitable for all.