Dichotic release from masking for speech

A dichotic method of listening to synthetic CV speech syllables was investigated, where the first formant (F1) is presented to one ear and the second and third formants (F2, F3) to the other ear. As a test parameter, the intensity of F2, F3 was varied. Compared to the binaural condition, dichotic presentation permits F2, F3 to remain effective as speech cues at significantly lower intensity levels. The results are given the following interpretation: peripheral masking, which occurs for ordinary binaural listening, is avoided when speech is heard dichotically. A similar release from masking was found in a second, related experiment where only the initial F2, F3 transitions were presented to one ear and the remainder of the syllable to the other.