Efficacy of a Coupler-based Fitting Approach for Experienced Users Receiving Replacement Hearing Aids

In the VA system, hearing loss is the second-most common service-connected condition
affecting 933,182 Veterans, exceeded only by tinnitus which affects 1,121,709 Veterans (data
from Veterans Benefit Report for Fiscal Year 2016). In FY 2016, the VA dispensed 750,075
hearing aids at a net procurement of nearly $270 million (report generated from VA Denver
Acquisition and Logistics Center [DALC] Remote Order Entry System [ROES]). Half of the
hearing aids dispensed were to experienced hearing aid users receiving replacement hearing
aids (Dennis, 2014). VA Audiology caseload is significant and Veterans can experience long
wait-times for fitting appointments to obtain new hearing aids (Office of the Inspector
General, 2014).

The purpose of the fitting appointment is to program and verify the hearing aids and orient
the patient to hearing aid use/care. For patients obtaining replacement hearing aids, the
orientation typically is unnecessary, and the programming is simplified; consisting mainly of
matching the individual's real-ear aided response (REAR) and hearing aid output to
appropriate target values. In contrast to adults, REAR measurements are not well-tolerated by
children due to the requirement for placement of a probe tube in the ear canal. Therefore, a
hearing aid fitting procedure that circumvents the need for in situ REAR measurements (real
ear coupler difference or RECD) is the standard-of-care (SoC) for children. Considerable
research clearly has shown the equivalency of in situ REAR and RECD fitting procedures (e.g.,
Moodie et al., 1994). RECD fitting procedures rarely are used with adults; however, such an
approach could preclude the need for direct physical contact with the patient at the time of
the hearing aid fitting. Three experiments are proposed. The purpose of the first study is to
evaluate coupler-based fitting approach for groups of experienced users obtaining replacement
hearing aids and compare the accuracy of those fittings to the prescription and their
outcomes to norms. The second study aims to develop correction factors for venting of
open-fit hearing aids. The third study will focus on comparing coupler-based fittings of
open-fit hearing aids (using correction factors developed from study two results) to an SoC
(active control) group who will have their open-fit hearing aids fitted in face-to-face
appointment via standard in situ REAR procedures. In Study 1 and 3, both groups will return
for in situ REARs and self-report outcomes assessment one month after the hearing-aid
fitting. The results of this study should determine the efficacy of a RECD-based, hearing-aid
fitting approach for experienced hearing-aid users who are receiving replacement hearing aids
consisting of a variety of styles. If the approaches are equivalent, then this study will
provide an evidence-based, RECD fitting approach that should result in greater patient
satisfaction and reduced costs.

Inclusion Criteria:

Study 1 and 3

- experienced hearing-aid users who are obtaining replacement VA-issued hearing aids of
the same style and manufacturer as their current hearing aids

- no more than a moderate sensorineural hearing loss (defined as < 60 dB HL pure-tone
average at 500, 1000, and 2000 Hz AU)

- symmetrical hearing between the ears as defined as no more than a 20 dB difference in
pure-tone thresholds at two consecutive frequencies

- 50% word-recognition abilities in quiet as measured during the diagnostic audiologic
evaluation

- An education-adjusted score of >21 on the Montreal Cognitive Assessment

- ability to read and write in English

Study 2 Veterans aged 18-85 years with sensorineural hearing loss

Exclusion Criteria:

Study 1 and 3

- outer or middle ear pathology as determined by otoscopy, immittance, and/or
audiometric testing (e.g., conductive or mixed losses)

- a significant change in hearing on audiogram obtained during the current study and
that obtained when fitted with the current (to-be replaced) hearing aids as defined by
a 10 dB decline in thresholds at three consecutive frequencies in either ear

- lack of phone or non-use of the phone

- unwilling or unable to be mailed hearing aids

- co-morbid condition that would preclude their participation

Study 2

- co-morbid condition that would preclude their participation

- outer or middle ear pathology as determined by otoscopy, immittance, and/or
audiometric testing (e.g., conductive or mixed losses)