Invertibility of a room impulse response

When a conversation takes place inside a room, the acoustic speech signal is linearly distorted by wall reflections. The rooms effect on this signal can be characterized by a room impulse response. If the impulse response happens to be minimum phase, it can easily be inverted. Synthetic room impulse responses were generated using a point image method to solve for wall reflections. A Nyquist plot was used to determine whether a given impulse response was minimum phase. Certain synthetic room impulse responses were found to be minimum phase when the initial delay was removed. For these cases a mimimum phase inverse filter was sucessfully used to remove the effect of a room impulse response on a speech signal.