Limitations to design predictions 0.00 ­5.00 ­10.00 ­15.00 ­20.00 273 dB ­25.00 ­30.00 ­35.00 ­40.00 ­45.00 ­50.00 0 0.25 0.5 0.75 1.0 1.25 Time (seconds) Figure 10.5 Energy/time curve (ETC). This ETC is a representation of a room not too dissimilar from the bare model plot in Figure 10.2(b). The bumps at 0.55, 0.85 and 1.15 s were due to traffic noise. The plot was from an unfinished room In small rooms, the truly diffuse sound field required to produce reverber- ation can never develop, but the relative energy in the modes, discrete reflex- ions, and diffused sound all contribute to the overall perceived sound. The Schroeder plots of Figures 10.2 and 10.3 shows the overall envelope of the