Reverberation Time Estimation Algorithm Accuracy

The task of estimating the reverberation time is relevant in the acoustic examination of premises for both civilian purposes (kindergartens, educational institutions, concert halls, etc.) and military purposes (control centers). Reverberation time measurement is usually performed by the method of inverse integration of the room impulse response. However, due to the existence of background noise, the problem of choosing the moment of time (truncation time) from which integration should begin arises. In this paper, the accuracy of the algorithm for calculating the reverberation time, where the truncation time is defined as the moment of approach to zero of the derivative of the “squaring - moving averaging” system output signal, is studied. Estimates of the bias, standard deviation, and total error for the values of the signal-to-noise ratio and reverberation time typical for classrooms are obtained. At a signal-to-noise ratio of 45 dB, for measurements in a wide frequency band of 80 Hz – 11 kHz, the total relative error of the reverberation time estimation does not exceed 6% for reverberation time values of 0.6–1.2 s. When measuring reverberation time in octave frequency bands, the error reaches 20% for the frequency band in the vicinity of 125 Hz, decreases to 10% for the frequency band in the vicinity of 500 Hz, and does not exceed 3% for the frequency band in the vicinity of 8 kHz.