Duration of frication noise required for identification of English fricatives.

Natural speech consonant-vowel (CV) syllables [( f, s, theta, s, v, z, ŏ] followed by [i, u, a]) were computer edited to include 20-70 ms of their frication noise in 10-ms steps as measured from their onset, as well as the entire frication noise. These stimuli, and the entire syllables, were presented to 12 subjects for consonant identification. Results show that the listener does not require the entire fricative-vowel syllable in order to correctly perceive a fricative. The required frication duration depends on the particular fricative, ranging from approximately 30 ms for [s, z] to 50 ms for [f, s, v], while [theta, ŏ] are identified with reasonable accuracy in only the full frication and syllable conditions. Analysis in terms of the linguistic features of voicing, place, and manner of articulation revealed that fricative identification in terms of place of articulation is much more affected by a decrease in frication duration than identification in terms of voicing and manner of articulation.