No differences in streaming efficiency were found between the perceptual dimensions linked to the F0 and the spectral envelope. For the normal hearing listeners without musical backgrounds, a greater difference on the perceptual dimension correlated to the temporal envelope is needed for stream segregation in CI users. The most efficient streaming cue for CI users was loudness. Regression between physical and perceptual cues then derived the minimal perceptual distance needed to segregate the melody. Multidimensional scaling analysis transformed the dissimilarity ratings into perceptual distances. In experiment 2, listeners were asked to rate the dissimilarity between melody patterns whose notes differed on the four physical properties simultaneously. Four physical properties of the distracter notes were changed. In experiment 1, participants rated the difficulty of segregating the melody from distracter notes. The melody segregation ability of 12 cochlear-implant recipients was tested using a new method to determine the perceptual distance needed to segregate a simple 4-note melody from a background of interleaved random-pitch distractor notes.
Brain plasticity induced by musical training can enhance the ability to segregate sound, leading to improvements in a variety of auditory abilities.
Our ability to listen selectively to single sound sources in complex auditory environments is termed “auditory stream segregation.”This ability is affected by peripheral disorders such as hearing loss, as well as plasticity in central processing such as occurs with musical training.