Talker head orientation related benefit as a function of masker-talker head angle

Understanding speech in multi-talker environments poses significant challenges as multiple speech signals compete for attention. One factor that plays a role in speech recognition in multi-talker environments is talker head orientation. In this study, we investigated the effect of talker head orientation related (THOR) spectral cues on speech recognition using eight different masker head orientation angles ranging from 0° (facing the listener) to 180° (facing away from the listener). The target talker was facing the listener in all conditions and maskers were co-located with the target. Target speech was digit triplets from a female talker, with a female two-talker masker consisting of narrative speech. A speech reception threshold was calculated for each condition as the mean of 6 reversals in a two-down one-up adaptive track. A THOR benefit was observed when maskers faced >45°. This benefit continually increased as masker head angle increased to 180°. Low-pass filtering stimuli at 8 kHz somewhat reduced the THOR benefit. The data indicate that the THOR benefit from spectral cues can be >6dB for the highest masker head angles but could reach >10 dB when additionally accounting for masker level reductions associated with masker head rotation. [Work supported by NIH grant R01DC019745.]