Page 220 - Master Handbook of Acoustics

FIGURE 11-9 Decay of octave bands of noise in a voice studio. Fluctuations due to modal
interference are greatest for low-frequency octaves containing fewer modes.

Reverberation Characteristic

Rooms absorb sound at different rates at different frequencies, producing different reverberation
times, and this can greatly influence the room’s sonic characteristic. For example, a room with longer
reverberation times at higher frequencies, but shorter reverberation times at low frequencies may be

described as sounding “thin” or “harsh.” Because reverberation time will vary at different
frequencies, it is common practice to measure reverberation times at different octaves. Rather than
plot amplitude versus time as in a reverberation time graph, this analysis plots reverberation time