Abstract
Background The effect of context on speech processing has been studied using different speech
materials and response criteria. The Repeat-Recall Test (RRT) evaluates listener performance
using high context (HC) and low context (LC) sentences; this may offer another platform
for studying context use (CU).
Objective This article aims to evaluate if the RRT may be used to study how different signal-to-noise
ratios (SNRs), hearing aid technologies (directional microphone and noise reduction),
and listener working memory capacities (WMCs) interact to affect CU on the different
measures of the RRT.
Design Double-blind, within-subject repeated measures design.
Study Sample Nineteen listeners with a mild-to-moderately severe hearing loss.
Data Collection The RRT was administered with participants wearing the study hearing aids under two
microphone (omnidirectional vs. directional) by two noise reduction (on vs. off) conditions.
Speech was presented from 0 degree at 75 dB sound pressure level and a continuous
speech-shaped noise from 180 degrees at SNRs of 0, 5, 10, and 15 dB. The order of
SNR and hearing aid conditions was counterbalanced across listeners. Each test condition
was completed twice in two 2-hour sessions separated by 1 month.
Results CU was calculated as the difference between HC and LC sentence scores for each outcome
measure (i.e., repeat, recall, listening effort, and tolerable time). For all outcome
measures, repeated measures analyses of variance revealed that CU was significantly
affected by the SNR of the test conditions. For repeat, recall, and listening effort
measures, these effects were qualified by significant two-way interactions between
SNR and microphone mode. In addition, the WMC group significantly affected CU during
recall and rating of listening effort, the latter of which was qualified by an interaction
between the WMC group and SNR. Listener WMC affected CU on estimates of tolerable
time as qualified by significant two-way interactions between SNR and microphone mode.
Conclusion The study supports use of the RRT as a tool for measuring how listeners use sentence
context to aid in speech processing. The degree to which context influenced scores
on each outcome measure of the RRT was found to depend on complex interactions between
the SNR of the listening environment, hearing aid features, and the WMC of the listeners.
Keywords
Repeat-Recall Test - semantic context use - directional microphone - realistic signal-to-noise
ratios
