title: Sources of Variability in Consonant Perception and Implications for Speech Perception Modeling.
abstract: The present study investigated the influence of various sources of response variability in consonant perception. A distinction was made between source-induced variability and receiver-related variability. The former refers to perceptual differences induced by differences in the speech tokens and/or the masking noise tokens; the latter describes perceptual differences caused by within- and across-listener uncertainty. Consonant-vowel combinations (CVs) were presented to normal-hearing listeners in white noise at six different signal-to-noise ratios. The obtained responses were analyzed with respect to the considered sources of variability using a measure of the perceptual distance between responses. The largest effect was found across different CVs. For stimuli of the same phonetic identity, the speech-induced variability across and within talkers and the across-listener variability were substantial and of similar magnitude. Even time-shifts in the waveforms of white masking noise produced a significant effect, which was well above the within-listener variability (the smallest effect). Two auditory-inspired models in combination with a template-matching back end were considered to predict the perceptual data. In particular, an energy-based and a modulation-based approach were compared. The suitability of the two models was evaluated with respect to the source-induced perceptual distance and in terms of consonant recognition rates and consonant confusions. Both models captured the source-induced perceptual distance remarkably well. However, the modulation-based approach showed a better agreement with the data in terms of consonant recognition and confusions. The results indicate that low-frequency modulations up to 16 Hz play a crucial role in consonant perception.
authors.affiliation: Hearing Systems Group, Department of Electrical Engineering, Technical University of Denmark, ∅rsteds Plads Building 352, room 108, 2800, Kongens Lyngby, Denmark. jzaar@elektro.dtu.dk.
authors.forename: Johannes
authors.initials: J
authors.lastname: Zaar
authors.affiliation: Hearing Systems Group, Department of Electrical Engineering, Technical University of Denmark, ∅rsteds Plads Building 352, room 120, 2800, Kongens Lyngby, Denmark.
authors.forename: Torsten
authors.initials: T
authors.lastname: Dau
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D010700:Phonetics; D059629:Signal-To-Noise Ratio; D013067:Speech Perception / Q000502:physiology
keywords: Auditory modeling; Envelope domain; Internal noise; Listener effects; Microscopic; Modulation filters; Noise effects; Perceptual distance; Talker effects