Abstract
Background:
Previous research in cochlear implant (CI) recipients with bilateral severe-to-profound
sensorineural hearing loss showed improvements in speech recognition in noise using
remote wireless microphone systems. However, to our knowledge, no previous studies
have addressed the benefit of these systems in CI recipients with single-sided deafness.
Purpose:
The objective of this study was to evaluate the potential improvement in speech recognition
in noise for distant speakers in single-sided deaf (SSD) CI recipients obtained using
the digital remote wireless microphone system, Roger. In addition, we evaluated the
potential benefit in normal hearing (NH) participants gained by applying this system.
Research Design:
Speech recognition in noise for a distant speaker in different conditions with and
without Roger was evaluated with a two-way repeated-measures design in each group,
SSD CI recipients, and NH participants. Post hoc analyses were conducted using pairwise
comparison t-tests with Bonferroni correction.
Study Sample:
Eleven adult SSD participants aided with CIs and eleven adult NH participants were
included in this study.
Data Collection and Analysis:
All participants were assessed in 15 test conditions (5 listening conditions × 3 noise
levels) each. The listening conditions for SSD CI recipients included the following:
(I) only NH ear and CI turned off, (II) NH ear and CI (turned on), (III) NH ear and
CI with Roger 14, (IV) NH ear with Roger Focus and CI, and (V) NH ear with Roger Focus
and CI with Roger 14. For the NH participants, five corresponding listening conditions
were chosen: (I) only better ear and weaker ear masked, (II) both ears, (III) better
ear and weaker ear with Roger Focus, (IV) better ear with Roger Focus and weaker ear,
and (V) both ears with Roger Focus. The speech level was fixed at 65 dB(A) at 1 meter
from the speech-presenting loudspeaker, yielding a speech level of 56.5 dB(A) at the
recipient's head. Noise levels were 55, 65, and 75 dB(A). Digitally altered noise
recorded in school classrooms was used as competing noise. Speech recognition was
measured in percent correct using the Oldenburg sentence test.
Results:
In SSD CI recipients, a significant improvement in speech recognition was found for
all listening conditions with Roger (III, IV, and V) versus all no-Roger conditions
(I and II) at the higher noise levels (65 and 75 dB[A]). NH participants significantly
benefited from the application of Roger in noise for higher levels, too. In both groups,
no significant difference was detected between any of the different listening conditions
at 55 dB(A) competing noise. There was also no significant difference between any
of the Roger conditions III, IV, and V across all noise levels.
Conclusions:
The application of the advanced remote wireless microphone system, Roger, in SSD CI
recipients provided significant benefits in speech recognition for distant speakers
at higher noise levels. In NH participants, the application of Roger also produced
a significant benefit in speech recognition in noise.
Key Words
cochlear implant - remote wireless microphone system - single-sided deafness - speech
recognition in noise
