Measurements of auditory navigation in virtual acoustic space

Auditory navigation in virtual acoustic space is a well-known aid for helping blind people orient in space. Methods used for generating virtual acoustic space are also useful in reproduction of realistic sounds in surround audio systems, video games, etc. In order to design an efficient virtual acoustic space or acoustic image, many psycho acoustic facts should be considered. To prove theoretical presumptions in practice, many tests need to be done. We developed an experimental system for testing variety of parameters. Using the experimental system, one can virtually place the sound source in almost any location in front of the listener's head. The system uses either pre-recorded sound files or produces space sound in real time with the use of arbitrary spatial sound model (i.e. the way of presenting head related transfer functions - HRTF) and arbitrary sound sources. The main goal of the research was to determine the possibilities of auditory navigation and to examine results of acoustic image resolution obtained in previous researches. Fifty test subjects underwent several experiments in which they were asked to locate the various sound sources. Experiments showed that the major problems were related to resolution. Test subjects were able to approximately find location very quick but they had problems locating it more precisely.