Reverberation chamber measurements typically rely upon spatially averaged squared pressure for the calculation of sound absorption, sound power, and other acoustic values. While a reverberation chamber can provide an approximately diffuse sound field, variations in sound pressure consistently produce uncertainty in measurement results. This paper explores the benefits of using total energy density or squared particle velocity magnitude (kinetic energy density) instead of squared pressure (potential energy density) for sound absorption and sound power measurements. The approaches are based on methods outlined in current ISO standards. The standards require a sufficient number of source-receiver locations to obtain suitable measurement results. The total and kinetic energy densities exhibit greater spatial uniformity at most frequencies than potential energy density, thus requiring fewer source-receiver positions to produce effective results. Because the total energy density is typically the most uniform of the three quantities at low frequencies, its use could also impact the usable low-frequency ranges of reverberation chambers. In order to employ total and kinetic energy densities for sound absorption measurements, relevant energy-based impulse responses were developed as part of the work for the assessment of sound field decays.

The Brigham Young University Acoustics Research Group has recently constructed two rectangular reverberation chambers for its research efforts. Steps have been taken to qualify the chambers for a variety of applications. Stationary diffusers and low-frequency absorbers were designed and installed as part of this process. This paper presents measurements taken at various stages of the installation to assess the impact of the diffusers and absorbers on the modal structure of the low-frequency fields.

Traditional reverberation chamber measurements, such as sound power and sound absorption measurements, rely on the evaluation of acoustic pressure at many field positions. Other field quantities could be better suited for these applications if they had greater spatial uniformity and required fewer source-receiver positions to produce accurate measurement results. This paper explores the possibility of using energy-based field quantities for this purpose and provides several analytical and experimental results to show their benefits.