ABSTRACT FOR THE MEETING 
OF THE GREATER BOSTON CHAPTER OF THE ACOUSTICAL SOCIETY OF AMERICA

on December 18, 2001 at the BU Castle

ON THE PHYSICAL IMPOSSIBILITY OF LOCALIZING A SOUND IN A ROOM AND HOW HUMAN LISTENERS DO IT ANYWAY.

By William M. Hartmann

Department of Physics and Astronomy Michigan State University East Lansing, MI, 48824 hartmann@pa.msu.edu

According to the standard psychoacoustical model, listeners localize sounds on the basis of interaural differences in signal level and arrival time. Listeners also use monaural (and possibly binaural) spectral information. However, these localization cues are usually badly distorted when the sounds occur in a room. A room leads to reflections and standing waves that make localization cues so unreliable that it ought to be impossible to localize a sound in a room.

The talk at the Boston University Castle will describe the subconscious strategies that listeners use to cope with with this difficult situation. It will summarize what is known about how listeners reweight the physical cues in attempt to find a self-consistent solution to the localization problem.

In view of the festive character of the season, the talk will include a convincing demonstration of the human reweighting strategy, as well as a digression about an audio recording technique for creating a convincing spatial impression with a small musical ensemble such as a string quartet.