Energy Decay Curve (EDC)

For measuring and defining reverberation time $t_{60}$ , Schroeder introduced the so-called energy decay curve (EDC) which is the tail integral of the squared impulse response at time $t$ :

$$\hbox{EDC}(t) \mathrel{\stackrel{\mathrm{\Delta}}{=}}\int_t^\infty h^2(\tau)d\tau$$

• $\hbox{EDC}(t)$ = total signal energy remaining in the reverberator impulse response at time $t$
• EDC decays more smoothly than the impulse response itself
• Better than ordinary amplitude envelopes for estimating $t_{60}$