A Mathematical Images Group Model to Estimate the Sound Level in a Close-Fitting Enclosure

Table 1

Large room diffuse model predictions of incident sound level reductions.

Sound absorption coefficient of hard surfaces	Front wall incidence SPL reduction for reverberant part for each ℎ value from 0.15 to 0.90 m.	Front wall incidence SPL reduction for total for each ℎ value from 0.15 to 0.90 m.
0.005	18.5	18.0
0.01	15.6	15.0
0.025	11.6	10.1
0.05	8.8	8.3