title: Information-bearing acoustic change outperforms duration in predicting intelligibility of full-spectrum and noise-vocoded sentences.
abstract: Recent research has demonstrated a strong relationship between information-bearing acoustic changes in the speech signal and speech intelligibility. The availability of information-bearing acoustic changes reliably predicts intelligibility of full-spectrum [Stilp and Kluender (2010). Proc. Natl. Acad. Sci. U.S.A. 107(27), 12387-12392] and noise-vocoded sentences amid noise interruption [Stilp et al. (2013). J. Acoust. Soc. Am. 133(2), EL136-EL141]. However, other research reports that proportion of signal duration preserved also predicts intelligibility of noise-interrupted speech. These factors have only ever been investigated independently, obscuring whether one better explains speech perception. The present experiments manipulated both factors to answer this question. A broad range of sentence durations (160-480 ms) containing high or low information-bearing acoustic changes were replaced by speech-shaped noise in noise-vocoded (Experiment 1) and full-spectrum sentences (Experiment 2). Sentence intelligibility worsened with increasing noise replacement, but in both experiments, information-bearing acoustic change was a statistically superior predictor of performance. Perception relied more heavily on information-bearing acoustic changes in poorer listening conditions (in spectrally degraded sentences and amid increasing noise replacement). Highly linear relationships between measures of information and performance suggest that exploiting information-bearing acoustic change is a shared principle underlying perception of acoustically rich and degraded speech. Results demonstrate the explanatory power of information-theoretic approaches for speech perception.
authors.affiliation: Department of Psychological and Brain Sciences, University of Louisville, Louisville, Kentucky 40292.
authors.forename: Christian E
authors.initials: CE
authors.lastname: Stilp
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000704:Analysis of Variance; D001302:Audiometry, Speech; D003463:Cues; D006801:Humans; D007257:Information Theory; D016014:Linear Models; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D013018:Sound Spectrography; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013067:Speech Perception; D013997:Time Factors; D014833:Voice Quality