Acoustic Echo Simulator

• Delay line length set to path-length difference:
  $$M = \frac{2r-d}{cT}$$
  where

  c = sound speed

  T = sampling period

• Gain coefficient $g$ set to relative attenuation:
  $$g = \frac{1/2r}{1/d} = \frac{d}{2r} = \frac{1}{\sqrt{1+(2h/d)^2}}$$

• $M$ typically rounded to nearest integer
• For non-integer $M$, delay line must be interpolated