Perceived reverberation depends on early decay, not total T60 measurement

Evidence

However, if the curve is of the double-slope form shown in Figure 6.15,then this simple relationship is broken. The net result is that, although the T60 reverberation time may be an appropriate value, because of the faster early decay to below 30 dB, we perceive the reverberation as being shorter than it really is. The psychoacoustic effect of this is that the space sounds “drier” than one would expect from a simple measurement of T60. Modern acoustic designers therefore worry much more about the early decay time (EDT) than they used to when designing concert halls. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1926

Categorization

• XREF: Links to Sabine’s original reverberation-time work in the prior paragraph and to the reader’s interest in how measured acoustics diverge from perception.