LAUSR

Modulation masking is known to impact speech intelligibility, but it is not clear how this phenomenon interacts with the perceptual segregation between the target speech and background noise. Using an experimental task in which listeners identified synthesized-vowel sequences in amplitude-modulated noises, a previous study from our laboratory found few signs of modulation masking, contrary to the findings of speech-on-speech masking experiments. It is hypothesized that modulation masking at a low rate (<6 Hz) may reflect failures of segregating the target speech from the noise. The current study systematically removed segregation cues and evaluated the amount of modulation masking. These segregation cues included the periodicity in the temporal fine structure of the target vowel sequences (in Exp. I) and the temporal regularity of the vowel sequences (in Exp. II). Results will be discussed in terms of the potential interactions between modulation masking and perceptual segregation.