Discrimination of intensity differences carried on formant transitions varying in extent and duration

Dorman (1974) found that small-intensity differences carried on the initial portions of consonantvowel syllables were not discriminable. Similar differences carried on steady-state vowels and on isolated formant transitions, however, were readily discriminable. He interpreted the difference between the first and latter conditions as a phonetic effect. Yet Pastore, Ahroon, Wolz, Puleo, and Berger (1975) found similar results using sine-wave analogs to Dorman's stimuli. They concluded that the effect is not phonetic, and that it is attributable to simple backward masking. The present studies observed the discriminability of intensity differences carried on formant transitions varying in extent and duration. Results support the conclusion of Pastore et al. to the extent that the effect is clearly not phonetic. However, these results and others suggest that simple peripheral backward masking is not a likely cause; instead, recognition masking may be involved. Moreover, the finding that phonetic-like processes occur elsewhere in audition does not necessarily impugn the existence of a speech processor; phonemic and phonological processes remain, as yet, unmatched.