Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

287Dimensions of Spatial Sound and Interface Styles

virtual sources to each sink. An image-model or ray-tracing algorithm can be used

to simulate the timing and direction of these individual reections, represented by

a nite impulse response (FIR) lter, which are then processed (usually digitally by

feed-forward tapped delay lines, like shift registers) as if they were separate sources

(Kendall etal. 1986). Each spatialized audio source, incident or reected, requires

its own DSP channel.

Late reverberation: Late eld reverberation typically represents source position-

independent ambience of a space. Reverberant implementations of spatial sound

sometimes employ a recursive (feed-backward, or autoregressive), or innite impulse

response (I ...