Background: Despite evidence suggesting inaccuracy in the default fittings provided by hearing
aid manufacturers, the use of probe-microphone measures for the verification of fitting
accuracy is routinely used by fewer than half of practicing audiologists.
Purpose: The present study examined whether self-perception of hearing aid benefit, as measured
through the Abbreviated Profile of Hearing Aid Benefit (APHAB; Cox and Alexander,
1995), differed as a function of hearing aid fitting method, specifically, manufacturer's
initial-fit approach versus a verified prescription. The prescriptive fit began at
NAL-NL1 targets, with adjustments based on participant request. Each of the two fittings
included probe-microphone measurement.
Research Design: A counterbalanced, cross-over, repeated-measures, single-blinded design was utilized
to address the research objectives.
Study Sample: Twenty-two experienced hearing aid users from the general Bay Pines VA Healthcare
System audiology clinic population were randomized into one of two intervention groups.
Intervention: At the first visit, half of the participants were fit with new hearing aids via the
manufacturer's initial fit while the second half were fit to a verified prescription
using probe-microphone measurement. After a wear period of 4–6 wk, the participants'
hearing aids were refit via the alternate method and worn for an additional 4–6 wk.
Participants were blinded to the method of fitting by utilizing probe-microphone measures
with both approaches.
Data Collection and Analysis: The APHAB was administered at baseline and at the end of each intervention trial.
At the end of the second trial period, the participants were asked to identify which
hearing aid fitting was “preferred.” The APHAB data were subjected to a general linear
model repeated-measures analysis of variance.
Results: For the three APHAB communication subscales (i.e., Ease of Communication, Reverberation,
and Background Noise) mean scores obtained with the verified prescription were higher
than those obtained with the initial-fit approach, indicating greater benefit with
the former. The main effect of hearing aid fitting method was statistically significant
[F (1, 21) = 4.69, p = 0.042] and accounted for 18% of the variance in the data (partial eta squared =
0.183). Although the mean benefit score for the APHAB Aversiveness subscale was also
better (i.e., lower) for the verified prescription than the initial-fit approach,
the difference was not statistically significant. Of the 22 participants, 7 preferred
their hearing aids programmed to initial-fit settings and 15 preferred their hearing
aids programmed to the verified prescription.
Conclusions: The data support the conclusion that hearing aids fit to experienced hearing aid
wearers using a verified prescription are more likely to yield better self-perceived
benefit as measured by the APHAB than if fit using the manufacturer's initial-fit
approach.
Key Words
Hearing aid - hearing impairment - patient outcome assessment - questionnaire - self-reports
