Binaural Room Impulse Response

While HRTF´s are measured in an anechoic chamber in order to avoid reflections it is also possible to make the same measurements in a room but then the filters are called binaural room impulse responses (BRIR's).

Binaural synthesis using a BRIR will create the sound image of a sound source in the room where the BRIR was recorded with full spatial information.

Synthesis with a BRIR is however much more computational demanding than synthesis using HRTF´s and several of the acoustical assumptions made regarding HRTF´s are not valid for BRIR's. Therefore 3D Sound by use of a BRIR database is less flexible.

By combining the HRTF database with a parametric model of the acoustic environment a flexible acoustic modeling system can be obtained. Much more flexible than using a BRIR database. The acoustics of the parametric approach is however less precise but the psychoacoustics difference may well be insignificant if the acoustic model is precise enough.