Multidimensional perceptual scaling of musical timbre by hearing-impaired listeners

Abstract

We examine of the impact of hearing loss and hearing aid processing on the perception of musical timbre. Our objective is to identify significant timbre cues for hearing-impaired listeners, and to assess the impact of hearing aid signal processing on timbre perception. Hearing aids perform dynamic, level-dependent spectrum shaping that may influence listeners' perception of musical instrument timbres and their ability to discriminate among them. Grey (Grey, J. M. 1977. Multidimensional perceptual scaling of musical timbres. JASA 61: 1270) showed that sustaining instrument tones equalized for level, loudness, and duration, are distinguished primarily along three perceptual dimensions that are strongly-correlated with the acoustical dimensions of: 1) spectral energy distribution, 2) spectral fluctuation, and 3) precedent high-frequency, low-amplitude energy. Following the work of Grey, we ask listeners having mild to moderately-severe sensorineural hearing loss to rate pairs of synthetic musical instrument tones according to dissimilarity in aided and unaided conditions. We analyze the dissimilarity judgments to identify acoustical correlates for the significant dimensions of timbre discrimination. This analysis helps us to objectively estimate the impact of hearing aid signal processing on the ability of hearing-impaired listeners to discriminate among musical instruments, an important component of musical listening. © 2009 Acoustical Society of America.