Intelligibility of read Japanese words with competing noise in virtual acoustic space

In this paper, we investigated the effect of a competing noise source on the intelligibility of target speech. We are currently investigating the possibility of realizing a network-based conference system in which individual users participating from stand-alone PCs share a common virtual space. We are currently focusing on the acoustic aspects of this conferencing system. The intelligibility improvement of the primary speech when the competing sources are localized away from the listener on the horizontal plane was investigated. The primary speaker was placed directly in front of the listener, and a single competing source was placed on the horizontal plane at various azimuths and distances. DRT intelligibility tests showed that intelligibility scores of over 70% are achieved when the competing source is placed at azimuths of more than 45 degrees away from the primary speech source. Increasing the distance of the competing source further enhances the intelligibility scores, as expected. These results show the feasibility of a multiparty audio conferencing system with a carefully controlled speaker location for intelligible speech.