Evaluation of artificial heads in listening tests

The localization performance was studied when subjects listened 1) to a rea l sound field and 2) to artificial-head recordings of the same sound field. The experiments took place in a standard listening room where each stimulu s (female speech) was emitted from one of 19 loudspeakers, and the subjects were to indicate the perceived sound source. The artificial-head recording s were made a) by the artificial heads' built-in microphones and b) by bloc ked ear canal microphones. The reproduction was carried out by carefully eq ualized headphones. Eight artificial heads were included in the investigati on, and 20 subjects participated, except for the experiment with recordings from built-in microphones, which was performed for eight subjects. When co mpared to real life, the localization performance with the artificial heads resulted in an increased number of errors independent of the recording tec hnique. In general, the directions in the median plane were frequently conf used, not only with nearby directions, but also with directions further awa y. For some artificial heads there was also an increase in confusions of di rections outside the median plane. A much better performance is obtainable with binaural recordings made in the ears of humans. This encourages the de sign and production of improved artificial heads.