Temporal effects in simultaneous masking by vowel and consonant-vowel maskers

Temporal effects in simultaneous masking were studied using synthetic vowel (V) and consonant-vowel (CV) maskers. For the steady-state V maskers (/i,a,u/), signals were presented at the beginning or in the temporal center of the masker. The masking patterns generally reflected the formant differences among the vowels, and the formant structure of each V masker was more clearly revealed when the signal was presented in the temporal center of the masker. For the CV maskers (/bi,gi/), signals were presented at the beginning of the (consonant portion of the) masker, at the beginning of the vowel portion of the masker, or in the temporal center of the masker. The second-formant difference between the maskers (observed acoustically at their onset) was generally revealed in the masking patterns when the signal was presented at the beginning of the consonant; this difference in the masking patterns was also present, to a lesser extent, when the signal was presented at the beginning of the vowel, where the two maskers were identical acoustically. The masking patterns for the two CV maskers were virtually identical when the signal was presented in the temporal center of the masker. These data extend previous tone-on-tone masking data and suggest that the auditory system requires a certain amount of time to represent most accurately the acoustic spectrum of both steady-state and dynamic complex maskers.