title: The effects of high presentation levels on consonant feature transmission.
abstract: The effect of high speech presentation levels on consonant recognition and feature transmission was assessed in eight participants with normal hearing. Consonant recognition in noise (0 dB signal-to-noise ratio) was measured at five overall speech levels ranging from 65 to 100 dB SPL. Consistent with the work of others, overall percent correct performance decreased as the presentation level of speech increased [e.g., G. A. Studebaker, R. L. Sherbecoe, D. M. McDaniel, and C. A. Gwaltney, J. Acoust. Soc. Am. 105(4), 2431-2444 (1999)]. Confusion matrices were analyzed in terms of relative percent information transmitted at each speech presentation level, as a function of feature. Six feature sets (voicing, place, nasality, duration, frication, and sonorance) were analyzed. Results showed the feature duration (long consonant duration fricatives) to be most affected by increases in level, while the voicing feature was relatively unaffected by increases in level. In addition, alveolar consonants were substantially affected by level, while palatal consonants were not. While the underlying mechanisms responsible for decreases in performance with level increases are unclear, an analysis of common error patterns at high levels suggests that saturation of the neural response and/or a loss of neural synchrony may play a role.
authors.affiliation: Dan Maddox Hearing Aid Research Laboratory, Vanderbilt Bill Wilkerson Center, 1215 21st Avenue South, Room 8310, Medical Center East, South Tower, Nashville, Tennessee 37232, USA. ben.hornsby@vanderbilt.edu
authors.forename: Benjamin W Y
authors.initials: BW
authors.lastname: Hornsby
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Trine
authors.forename: Ralph N
authors.initials: RN
authors.lastname: Ohde
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008144:Loudness Perception / Q000502:physiology*; D008297:Male; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking / Q000502:physiology*; D013063:Speech Discrimination Tests; D013067:Speech Perception / Q000502:physiology*