Adaptation to novel foreign-accented speech and retention of benefit following training: Influence of aging and hearing loss

Abstract

Adaptation to speech with a foreign accent is possible through prior exposure to talkers with that same accent. For young listeners with normal hearing, short term, accent-independent adaptation to a novel foreign accent is also facilitated through exposure training with multiple foreign accents. In the present study, accent-independent adaptation is examined in younger and older listeners with normal hearing and older listeners with hearing loss. Retention of training benefit is additionally explored. Stimuli for testing and training were HINT sentences recorded by talkers with nine distinctly different accents. Following two training sessions, all listener groups showed a similar increase in speech perception for a novel foreign accent. While no group retained this benefit at one week post-training, results of a secondary reaction time task revealed a decrease in reaction time following training, suggesting reduced listening effort. Examination of listeners' cognitive skills reveals a positive relationship between working memory and speech recognition ability. The present findings indicate that, while this no-feedback training paradigm for foreign-accented English is successful in promoting short term adaptation for listeners, this paradigm is not sufficient in facilitation of perceptual learning with lasting benefits for younger or older listeners.

Figures

FIG. 1.

Speech recognition performance and standard errors across training and test lists for three listener groups. Solid vertical lines indicate separate visit days, and dashed lines indicate training sessions. Test conditions (Pre-test, midway, post-test, retention test) are circled. Error bars represent standard error of measurement.

FIG. 2.

Mean speech recognition performance and standard errors across test lists (Pre-test, midway, post-test, retention test) for three listener groups. Error bars represent standard error of measurement.

FIG. 3.

Mean normalized relative reaction times and standard errors across test lists (Pre-test, midway, post-test, retention test) for three listener groups. Error bars represent standard error of measurement.

FIG. 4.

Patterns of learning during training sessions, by listener group. Grey lines represent individual training curves; black lines represent the group mean. Training materials include identical lists spoken by talkers with different L1 accent.

FIG. 5.

Scatterplots showing the relationship between L-SPAN sores and speech recognition accuracy for participants in the three listener groups, measured at the four test intervals (top left panel: pre-test; top right panel: midway test; bottom left panel: post test; bottom right panel: retention test). The solid line in each plot represents the overall correlation with L-SPAN scores at each test condition.