Visualization of a sound field is a powerful tool for understanding acoustic phenomena. Methods using a microphone array such as beamforming and near-field acoustic holography have widely been studied, and these have been applied to industrial problems. As alternative choices for the visualization of the sound field, optical methods have gained a considerable amount of attention due to their capability of non-intrusive measurement. These include laser Doppler vibrometry, Shadowgraphy, Schlieren method, optical digital holography, and parallel phase-shifting interferometry (PPSI). These methods are well developed for the visualization of propagating sound wave in a free field. Also, as these methods can observe the sound field without installing any instruments into the field to be measured, they have the potential to achieve visualization of sound inside a cavity, which is quite important for duct acoustics. This paper presents the single-shot visualization of the sound field inside a transparent cavity using PPSI with a high-speed camera, as well as the brief review of the development of the optical measurement of sound. For the experiments, the sound field inside of a ported speaker box made by acrylic plates was measured. Acoustics resonances and mode patterns inside the box were successively captured.
|Publication status||Published - 2018 Jan 1|
|Event||47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018 - Chicago, United States|
Duration: 2018 Aug 26 → 2018 Aug 29
|Other||47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018|
|Period||18/8/26 → 18/8/29|
ASJC Scopus subject areas
- Acoustics and Ultrasonics