Perceptual Learning of Spectrally Degraded Speech may be Impaired by Auditory Distraction in Adolescence04/09/2019
Adults must attend to spectrally degraded (noise-vocoded, NV) speech to learn to understand it but attention develops throughout childhood, and therefore this requirement may not be the same for older children and adolescents. The aim of this study was to evaluate the role of attention in adolescents’ learning to comprehend NV speech. Listeners aged 10-17 years were exposed to a series of 6-band NV sentences. All listeners completed a five-sentence pre-training test and a 20-sentence post-training test, during which they listened to the sentences and repeated them aloud. During the training phase, listeners were divided into three groups: two groups heard 15 NV sentences simultaneously with a series of amplitude-modulated noises. One of these groups was instructed to detect a target amongst the noises while another group repeated back the NV sentences. The third group served as control listeners and played a video game in silence. Preliminary data show that the adolescents who attended to the NV speech in training did not benefit from that experience, suggesting that the presence of irrelevant sounds may have prevented their learning. This outcome indicates that immature auditory attention may interfere with adolescents’ perceptual learning abilities. All three groups improved over the 20 sentences of the post-training test, indicating that learning was possible when the NV sentences were presented alone. If this preliminary result holds, it suggests that adolescent listeners adjusting to new hearing aids or cochlear implants may benefit most from listening to speech in environments with few distractions.