Inaccuracies in sound pressure level determination from room impulse response.

The integration over discrete squared room impulse response (RIR) leads to the sound pressure level (SPL). However, certain inaccuracies in SPL determination appear as a consequence of influences of finite integration upper limit (UL) and noise. Due to that, these influences are investigated using two types of RIRs: those generated by simulation and those measured in the room. The investigations show that for RIRs with sufficiently small noise floors (below -20 or -15 dB) acceptably small inaccuracies are obtained if the integration UL is placed at T/3 (alternatively at T/4). A more general solution is to set UL at the knee representing the point where main decay intersects noise floor. For even smaller inaccuracies, it would be better to set UL at the point somewhat before the knee called optimal UL. The influences of finite integration UL and noise can also be reduced by implementation of finite UL compensation and noise subtraction.