Diffuse sound reflection by maximum−length sequences

Abstract

Low−correlation sequences, such as ’’maximum−length’’ and Barker sequences and certain complex (magnitude one) sequences having flat power spectra, are ideally suited for designing surfaces of hard walls with highly diffuse reflections. Recent subjective−preference evaluations [M. R. Schroeder, D. Gottlob, and K. F. Siebrasse ’’Comparative Study of European Concert Halls’’, J. Acoust. Soc. Am. 56, XXX−XXX (1974)] indicate that low−loss, high−scatter surfaces may be required for better concert−hall acoustics. Surfaces shaped to give reflection coefficients according to such sequences show the expected high scatter in model experiments with microwaves. Subject Classification: 55.20, 55.40.