The Effect of Timbre and Loudness on Melody Segregation

Abstract

The aim of this study was to examine the effects of three acoustic parameters on the difficulty of segregating a simple 4-note melody from a background of interleaved distractor notes. Melody segregation difficulty ratings were recorded while three acoustic parameters of the distractor notes were varied separately: intensity, temporal envelope, and spectral envelope. Statistical analyses revealed a significant effect of music training on difficulty rating judgments. For participants with music training, loudness was the most efficient perceptual cue, and no difference was found between the dimensions of timbre influenced by temporal and spectral envelope. For the group of listeners with less music training, both loudness and spectral envelope were the most efficient cues. We speculate that the difference between musicians and nonmusicians may be due to differences in processing the stimuli: musicians may process harmonic sound sequences using brain networks specialized for music, whereas nonmusicians may use speech networks.