Sound transmission experiments from an impulsive source near rigid wedges

Experimental sound transmissions in air from a spark source to a small microphone were made near rigid wedges. Two types of experiments were made. The first experiments were transmissions within an approximately 12° wedge and a 52° wedge. The Biot‐Tolstoy wedge solution [I. Tolstoy, Wave Propagation (McGraw‐Hill, New York, 1973)] was used to calculate the theoretical impulse response. The “free air” transmission from the spark source was convolved with the theoretical transmission. The transmissions within the wedge gave finite sets of multiple reflections or image arrivals and a diffraction arrival. The diffraction was sensitive to leaks at the wedge apex. Theory and experiment matched. The second set of experiments was made near a 270° wedge. Arrivals were the direct reflection and the diffraction. The image reflection when the specular “reflection point” was very near the wedge apex was of interest. Comparisons of data and theoretical signals using Biot‐Tolstoy theory were excellent. Theoretical diffraction signals calculated with Trorey's theory had poor matches [A. W. Trorey, Geophysics 35, 762–784 (1970)].