An investigation of human internal representation of auditory space

The current thesis broadens the knowledge on auditory space perception by addressing a series of gaps in literature on the effect of reverberation, stimulus type and sound source location for distance and azimuth judgments (made in isolation and simultaneously), sound localization of looming sounds, and room size judgments.Five studies were developed to address the research questions raised in the current thesis. Using virtualization methods, a series of rooms were generated varying in size and acoustic features (anechoic vs reverberant, T 60 = 1.7 s). Within these virtual rooms, sounds were generated at different distances and angles, and for different types of stimuli (speech, speech-shaped noise, bike bell sound, tone). Depending on the study, participants were asked to estimate a) the auditory distance (Study 1), b) the sound azimuth (Study 2), c) both the azimuth and the distance simultaneously (Study 3), d) the distance of the starting and ending point of moving sounds (Study 4), c) the room size (Study 5).Reverberation improved accuracy scores for distance judgments of static and moving sounds. No detrimental effect of reverberation was found for azimuth judgments of speech sounds. No significant differences in accuracy scores were found when azimuth and distance judgments were made in isolation or simultaneously. Room size judgments were found to correlate positively with the farthest perceived distance.The findings presented in the thesis provide baseline data for normally sighted individuals that will help in future work to assess spatial abilities in people with and without visual impairment and broaden the knowledge on auditory space perception with vision loss.