A previously developed spherical microphone array [J. Acoust. Soc. Am., 112(5), 1980-1991 (2002)] has been used for the identification of localized weak spots in an otherwise highlyinsulating wall (sound transmission class (STC) rating of 56). A sound source and the array were placed on opposite sides of a wall sample constructed between two reverberation rooms. The omnidirectional impulse response was measured to each of the 32 array microphones, and subsequent beamforming resulted in 60 directional impulse responses at the array position, distributed over all directions. This set of responses was analyzed to identify directions of peak sound transmission through the wall. The wall was tested in three configurations: 1. with no intentional sound leaks (STC 56), 2. with a 5.4 cm diameter hole cut clear through (STC 53), and 3. with a 3.8 cm diameter sealed-end pipe passed through the 5.4 cm hole (STC 56). The results obtained with the array approach are compared to a "brute force" scan with a microphone located 0.25 m from the wall. Indications are that the array approach is capable of detecting minor defects in the wall.
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