Page 95 - Master Handbook of Acoustics

FIGURE 4-19 The effects of lateral reflections on the perception of the direct sound in a simulated
stereo arrangement. These measurements were made in anechoic conditions, lateral angles 45°to 90°,
with speech as the signal. Curve A is the absolute threshold of audibility of the reflection. Curve B is
the image shift/broadening threshold. Curve C is the lateral reflection perceived as a discrete echo.
(A and B, Olive and Toole, and Toole.) (C, Meyer and Schodder, and Lochner and Burger.)

To assist in the calculations mentioned previously, the following equations can be applied:

This assumes 100% reflection at the reflecting surface. Both path lengths are measured in feet; the
speed of sound is measured in feet per second.

This assumes inverse square propagation. Both path lengths are measured in feet.