Abstract
Background:
Older adults often struggle with accurate perception of rate-altered speech and have
difficulty understanding speech in noise. The acceptable noise level (ANL) quantifies
a listener’s willingness to listen to speech in background noise and has been found
to accurately predict hearing aid success. Based on the difficulty older adults experience
with rapid speech, we were interested in how older adults may change the amount of
background noise they willingly accept in a variety of speech rate conditions.
Purpose:
To determine the effects of age and speech rate on the ANL.
Research Design:
A quasi-experimental mixed design was employed.
Study Sample:
Fifteen young adults (19–27 yr) and fifteen older adults (55–73 yr) with audiometrically
normal hearing or hearing loss within age-normed limits served as participants.
Data Collection and Analysis:
Most comfortable listening levels (MCLs) and background noise levels (BNLs) were measured
using three different speech rates (slow, normal, and fast). The ANL was calculated
by subtracting BNL from MCL. Repeated measures analysis of variances were used to
analyze the effects of age and speech rate on ANL.
Results:
A significant main effect of speech rate was observed; however, a significant main
effect of age was not found. Results indicated that as speech rate increased the ANLs
increased. This suggests that participants became less accepting of background noise
as speech rates increased.
Conclusions:
The findings of the present study provide support for communication strategies that
recommend slowing an individual’s speaking rate and/or reducing background noise,
if possible. Participants in the present study were better able to cope with background
noise when the primary stimulus was presented at slow and normal speaking rates.
Key Words
acceptable noise level - background noise level - most comfortable listening level
- speech rate - temporal processing
