Effect of auditory spatial attention in rear side

Abstract

When human listeners direct the auditory selective attention to a specific direction, the listener can easily extract target sound from this direction, even under the noisy environment (commonly known as the cocktail-party effect). Although the auditory spatial attention can be directed to any directions around the listeners including rear side, it is still unclear how much the auditory spatial attention in rear side influences this phenomenon. In the present study, we investigated the effect of auditory spatial attention directing to the location behind the listener in a multi-talker environment and compared between this result and the previous result in front of the listener. For the purpose, the word intelligibility was measured for the target speech among non-target speech sounds spatially distributed around the target. The target sound was presented from the direction where the listener attended. To control the listener's attention, we manipulated the probability of target presentation directions or indicated the target direction a priori. The results revealed the improvement of word intelligibility by directing attention to a direction in the rear side, similarly to the effect of attention in the front side. This suggests that there is no directional dependency in the effect of auditory spatial attention.