Release from energetic and informational masking as revealed by listening effort and speech intelligibility
* Presenting author
Abstract:
Normal-hearing listeners can exploit different unmasking cues to recognize target speech in complex speech-on-speech masking conditions. While this capability is typically measured as improvement in speech intelligibility, this study additionally investigated the release from perceived listening effort that could be achieved by three unmasking cues (spatial separation, gender differences, and masker time reversal). Speech intelligibility and categorically scaled listening effort were measured for a fixed target talker masked by two competing talkers with no unmasking cues or one to three unmasking cues. In addition to natural stimuli, measurements were also conducted with so-called ‘glimpsed speech’ to estimate the relative amounts of informational and energetic masking as well as the effort associated with source segregation. For normal-hearing listeners, all unmasking cues as well as glimpsing improved intelligibility and reduced listening effort. Providing more than one cue was beneficial in overcoming informational masking. The reduction in listening effort due to glimpsing corresponded to increases in signal-to-noise ratio of more than 15 dB, indicating that a significant amount of listening effort was devoted to segregating the target from the maskers. For hearing-impaired listeners, the benefit was reduced and varied considerably across subjects.