A psychoacoustic method for studying the necessary and sufficient perceptual cues of American English fricative consonants in noise

In a previous study on plosives, the 3-Dimensional Deep Search (3DDS) method for the exploration of the necessary and sufficient cues for speech perception was introduced (Li , (2010). J. Acoust. Soc. Am. 127(4), 2599-2610). Here, this method is used to isolate the spectral cue regions for perception of the American English fricatives /integral, , s, z, f, v, theta, (sic)/ in time, frequency, and intensity. The fricatives are analyzed in the context of consonant-vowel utterances, using the vowel /alpha/. The necessary cues were found to be contained in the frication noise for /integral, (sic), (sic), z, f, v/. 3DDS analysis isolated the cue regions of /s, z/ between 3.6 and 8 [kHz] and /integral, (sic)/ between 1.4 and 4.2 [kHz]. Some utterances were found to contain acoustic components that were unnecessary for correct perception, but caused listeners to hear non-target consonants when the primary cue region was removed; such acoustic components are labeled conflicting cue regions. The amplitude modulation of the high-frequency frication region by the fundamental F0 was found to be a sufficient cue for voicing. Overall, the 3DDS method allows one to analyze the effects of natural speech components without initial assumptions about where perceptual cues lie in time-frequency space or which elements of production they correspond to. (C) 2012 Acoustical Society of America. [http://dx.doi.org/10.1121/1.4747008]