Perceptual Learning under Ci Simulation

Adaptation to the acoustic world following cochlear implantation does not typically include formal training or extensive audiological rehabilitation. Can cochlear implant (CI) users benefit from formal training, and if so, what type of training is best? This study used a pre/post-test design to evaluate the efficacy and generalization of training in normal hearing subjects listening to CI simulations (8-channel sinewave vocoder). Subjects were trained with words (simple or complex), sentences (meaningful or anomalous), or environmental stimuli, and then were tested using an open-set identification task. Subjects were trained on only one type of material but were tested on all materials. All groups showed significant improvement as a result of training, which successfully generalized to some, but not all stimulus materials. For easier tasks, all types of training generalized equally well. For more difficult tasks, training specificity was observed. Training on speech did not generalize to the recognition of environmental signals; however, training on environmental signals successfully generalized to speech. These data demonstrate that the perceptual learning of degraded speech is highly context-dependent and that the specific stimulus materials that a subject experiences during training have a substantial impact on generalization to new materials.