Jongman et al.: Context Effects in Fricative Perception 1 Journal of Speech, Language, and Hearing Research • Vol. 46 • ?–? • December 2003 • ©American Speech-Language-Hearing Association 1092-4388/03/4606-xxxx Allard Jongman University of Kansas, Lawrence Yue Wang* Brian H. Kim** Cornell University, Ithaca, NY Contributions of Semantic and Facial Information to Perception of Nonsibilant Fricatives Most studies have been unable to identify reliable acoustic cues for the recogni- tion of the English nonsibilant fricatives /f, v, T, D/. The present study was designed to test the extent to which the perception of these fricatives by normal-hearing adults is based on other sources of information, namely, linguistic context and visual information. In Experiment 1, target words beginning with /f/, /T/, /s/, or /S/ were preceded by either a semantically congruous or incongruous precursor sentence. Results showed an effect of linguistic context on the perception of the distinction between /f/ and /T/ and on the acoustically more robust distinction between /s/ and /S/. In Experiment 2, participants identified syllables consisting of the fricatives /f, v, T, D/ paired with the vowels /i, A, u/. Three conditions were contrasted: Stimuli were presented with (a) both auditory and visual information, (b) auditory information alone, or (c) visual information alone. When errors in terms of voicing were ignored in all 3 conditions, results indicated that perception of these fricatives is as good with visual information alone as with both auditory and visual information combined, and better than for auditory information alone. These findings suggest that accurate perception of nonsibilant fricatives derives from a combination of acoustic, linguistic, and visual information. KEY WORDS: perception, fricatives, semantic context, facial context M ost research on fricatives has not been able to identify consis- tent acoustic characteristics that may serve to distinguish the labiodental (/f, v/) and dental (/T, D/) fricatives. Neither spec- tral, temporal, nor amplitude properties of the frication noise have been shown to reliably distinguish /f/ from /T/ and /v/ from /D/. Results from perceptual experiments suggest that cues to the perception of labioden- tal and dental fricatives are located in the transition and vocalic portion of fricative-vowel syllables rather than the noise portion (e.g., Harris, 1958; LaRiviere, Winitz, & Herriman, 1975). However, stable acoustic differences between /f, v/ and /T, D/, in terms of vocalic attributes, remain to be documented. This difficulty in determining the defining acoustic properties has been mirrored at the perceptual level. Among fricatives, /f/ and /T/ and /v/ and /D/ are most easily confused (e.g., Balise & Diehl, 1994; Jongman & Wang, submitted). Given the reported difficulty in recognition of these fricatives, G. A. Miller and Nicely (1955) hypoth- esized that the distinction between /f/ and /T/ and between /v/ and /D/ may be based on nonacoustic information: *Currently at SUNY Buffalo, Buffalo, NY **Currently at Michigan State University, East Lansing AQ1 AQ2