Possibility of simplifying head shape with the effect of head movement for an acoustical telepresence robot: TeleHead

We built an acoustical telepresence robot named TeleHead, which has a user-like dummy head and whose movement is synchronized with the user's head movement in real time. An accurate-shape user-like dummy head improves sound localization accuracy, but making an accurate-shape user-like dummy head for all users is not realistic. There have been many efforts to simplify dummy heads without head movement in order to make a dummy head suitable for all users. Head movement also improves sound localization accuracy. Therefore, we are trying to simplify TeleHead's head shape by taking the effect of head movement into consideration. In this work, we made two types of simplified dummy heads, a ball-like dummy head and a ball-like dummy head with a user-like pinna, and used them in sound localization experiments. The experimental results show that the pinna is very important for sound localization in the median plane. Head movement can improve sound localization and subjects can localize sound with another person's pinna. However, it is hard for subjects to localize a sound without a pinna even with head movement. In addition, the acoustical characteristics of each dummy head are significantly different. The results indicate the possibility of using a ball-like dummy head with a generic pinna for acoustical telepresence robots.