Informational and energetic masking effects in the perception of two simultaneous talkers

TLDR

Monaural cues, not just binaural cues, are crucial for perceiving multiple simultaneous speech signals. The study measured target phrase intelligibility masked by a single competing phrase across varying SNRs, using same‑talker, same‑sex, and different‑sex voice pairs. Informational masking dominated over energetic masking, with masking severity strongly tied to voice similarity—best with different‑sex talkers, worst with the same talker—and performance plateaued below 0 dB SNR, indicating that informational and energetic masking play distinct roles in competing speech perception.

Abstract

Although most recent multitalker research has emphasized the importance of binaural cues, monaural cues can play an equally important role in the perception of multiple simultaneous speech signals. In this experiment, the intelligibility of a target phrase masked by a single competing masker phrase was measured as a function of signal-to-noise ratio (SNR) with same-talker, same-sex, and different-sex target and masker voices. The results indicate that informational masking, rather than energetic masking, dominated performance in this experiment. The amount of masking was highly dependent on the similarity of the target and masker voices: performance was best when different-sex talkers were used and worst when the same talker was used for target and masker. Performance did not, however, improve monotonically with increasing SNR. Intelligibility generally plateaued at SNRs below 0 dB and, in some cases, intensity differences between the target and masking voices produced substantial improvements in performance with decreasing SNR. The results indicate that informational and energetic masking play substantially different roles in the perception of competing speech messages.