Subject: Re: Directional Perception From: Bradley Wood Libbey <gt1556a(at)PRISM.GATECH.EDU> Date: Tue, 16 Jan 2001 15:04:32 -0500John Neuhoff and List, I don't know of any papers dealing with your interesting questions directly. Just some food for thought. > ...is there free-field localization work in which the loudspeaker does > not face the listener directly? Source directivity is usually dependent on frequency. It would seem that some prior knowledge of the source itself would be required to perform the task in stationary free-field conditions. Do listeners know this frequency dependency? Would they need to listen to the source for multiple orientations before estimates could be made? In echoic environments additional information is available: Direct/reverberant amplitude ratios commonly associated with distance judgements may also be used to determine orientation. The frequency content of the direct signal versus that of the reverberant field could also provide clues. I don't believe that room echoes are processed as separate sources. Excepting special cases where spectral characteristics change or delays are large. Perhaps the directional frequency characteristics of a complex source are an exception? Brad Libbey GA Tech