ASA 124th Meeting New Orleans 1992 October

3aAA9. Full-wave modeling of the transmission of sound over theater seats: Far-field investigation.

Dominique J. Cheenne

Robert D. Kubik

Robert C. Maher

Ezekiel Bahar

Dept. of Elec. Eng., 209 N WSEC, Univ. of Nebraska, Lincoln, NE 68588

The full-wave theory [E. Bahar, J. Acoust. Soc. Am. 89, 19--26 (1991)] is applied to a computer simulation of sound transmission over simplified rows of theater seats. The investigation is concerned with the acoustic response in the far field for variable angles of incidence. The model consists on 1, 3, 5, or 8 rows, both short and tall seats, with narrow and wide spacings, for a total of four seating configurations. The surface is described if terms of its adiabatic bulk modulus. The influence of seat spacing on the backscatter appears to be quite relevant for all angles of incidence regardless of the seat height. Widely spaced seats lead to more irregular responses than narrowly spaced seats. These results suggest the need for separation between the spectral and backscattered energy during future experiments. The near-field investigation of this problem is also under way and will include a comprehensive assessment of the model using experimental data obtained by others [J. S. Bradley, J. Acoust. Soc. Am. 90, 324--333 (1991)].