The reverberation and absorption characteristics of a water-filled chamber with and without a pressure-release wall lining

The requirements for a reverberation chamber in air have been described in the appropriate standards, but there is no mention that these same requirements cannot be applied to underwater reverberation chambers. A number of acoustic measurements were made to determine the reverberation time and absorption characteristics of an underwater chamber with and without a pressure-release wall covering. The reverberation times were found to be faster than the transient response times of conventional analog equipment. Therefore, a digital computer was employed to filter the data and to determine the slope, and thus, the reverberation time by using a linear, least-squares curve fit. The pressure-release wall covering was found to reduce the average sound absorption coefficients to values acceptable for a reverberation chamber based on the standards for air acoustics.