Reverberation-Room Acoustics. II: Effects of Absorptive Floor, Suspended Ceiling Panels, and Diffusers on Speech and Music

Abstract

The results of the preceding investigation [Paper 5A4, this meeting] indicated that, with the floor absorptive, the suspended panels and the diffusers (located in the space below the panels) would greatly affect the quality of music and the intelligibility of speech. Recordings of speech and music (a trumpet, a violin, and the Roth String Quartet) in the anechoic chamber, played back in the reverberation room, under conditions that we had previously investigated, revealed some interesting and probably useful results. For example, speech articulation and the quality of music were greatly improved by introducing diffusion in the lower space. even though the “reverberation time” (estimated by projecting linearly the early decay to 60 dB) was of the order of 3.0 sec. The results are demonstrated with tape recordings; they suggest that large diffusers may have a more useful effect on room acoustics, for speech as well as music, than we have generally supposed.