Cylindrical acoustical holography applied to full-scale jet noise.

Near-field acoustical holography methods are used to predict sound radiation from an engine installed on a high-performance military fighter aircraft. Cylindrical holography techniques are an efficient approach to measure the large and complex sound fields produced by full-scale jets. It is shown that a ground-based, one-dimensional array of microphones can be used in conjunction with a cylindrical wave function field representation to provide a holographic reconstruction of the radiated sound field at low frequencies.

Acoustical and vibrometry analysis of a large Balinese gamelan gong.

The Balinese gamelan gong ageng wadon produces distinct acoustic beating (called ombak) when struck. This phenomenon is explored using both acoustical and vibrometry measurements. The measurements have revealed the beating has two sources.