Appendix II: Sample Suite Perception
1) Mono Noise Mask, 0Hz tone SPD
2) Stereo Noise Mask, 0Hz tone SPD
Siren fades away into harsh white noise, faster for the mono
noise mask than the stereo. The stereo noise mask is more
"listenable", acoustically inhabiting a very wide
three-dimensional sense of auditory space.
3) Mono Noise Mask, 1Hz tone SPD
4) Stereo Noise Mask, 1Hz tone SPD
Same as above, only the siren warble appears to bounce slowly
between the left and right ears as its phase modulates. The siren
masks slightly earlier (hence, more easily) than at the 0Hz SPD
rate.
5) Mono Noise Mask, 10Hz tone SPD
6) Stereo Noise Mask, 10Hz tone SPD
Same as for 0Hz SPD, except the siren masks significantly
earlier. As before, the sound gets lost among the Mono Noise Mask
before the Stereo noise mask. This is true for all the tests. The
left-right bouncing siren effect is too fast at this rate to be
perceived as such, and simply sounds ‘monophonic’
(stationary).
7) Mono Noise Mask, 100Hz tone SPD
8) Stereo Noise Mask, 100Hz tone SPD
In this, the most extreme case, the sirens mask easiest of all. The phasing effect is so fast at this rate that auditory artifacts are clearly audible as a stationary ring-modulation type of effect. Despite the novelty of this new sound, it gets lost among the noise earliest, and among the mono noise earliest of all.