Abstract
Background Adults and children with sensorineural hearing loss (SNHL) have trouble understanding
speech in rooms with reverberation when using hearing aid amplification. While the
use of amplitude compression signal processing in hearing aids may contribute to this
difficulty, there is conflicting evidence on the effects of amplitude compression
settings on speech recognition. Less clear is the effect of a fast release time for
adults and children with SNHL when using compression ratios derived from a prescriptive
procedure.
Purpose The aim of the study is to determine whether release time impacts speech recognition
in reverberation for children and adults with SNHL and to determine if these effects
of release time and reverberation can be predicted using indices of audibility or
temporal and spectral distortion.
Research Design This is a quasi-experimental cohort study. Participants used a hearing aid simulator
set to the Desired Sensation Level algorithm m[i/o] for three different amplitude
compression release times. Reverberation was simulated using three different reverberation
times.
Participants Participants were 20 children and 16 adults with SNHL.
Data Collection and Analyses Participants were seated in a sound-attenuating booth and then nonsense syllable
recognition was measured. Predictions of speech recognition were made using indices
of audibility, temporal distortion, and spectral distortion and the effects of release
time and reverberation were analyzed using linear mixed models.
Results While nonsense syllable recognition decreased in reverberation release time did not
significantly affect nonsense syllable recognition. Participants with lower audibility
were more susceptible to the negative effect of reverberation on nonsense syllable
recognition.
Conclusion We have extended previous work on the effects of reverberation on aided speech recognition
to children with SNHL. Variations in release time did not impact the understanding
of speech. An index of audibility best predicted nonsense syllable recognition in
reverberation and, clinically, these results suggest that patients with less audibility
are more susceptible to nonsense syllable recognition in reverberation.
Keywords
hearing loss - hearing aids - speech perception - adults and children