Signal processing for optical sound field measurement and visualization

Kohei Yatabe, Kenji Ishikawa, Yasuhiro Oikawa

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)

Abstract

Accurately measuring sound pressure is not an easy task because every microphone has its own mechanical and electrical characteristics. Moreover, the existence of a measuring instrument inside the field causes reflection and diffraction which deform the wavefront of sound to be measured. Ideally, a sensing device should not have any characteristic nor exist inside a measuring region. Although it may sound unrealistic, optical measurement methods are able to realize such ideal situation. Optical devices can be placed outside the sound field, and some of the sensing techniques, which decode information of sound from the phase of light, are able to cancel optical and electrical characteristics. Thus, optical sound measurement methods have possibility of achieving higher accuracy than ordinary sound measurement in principle. However, they have two main drawbacks that have prevented their applications in acoustics: (1) point-wise information cannot be obtained directly because observed signal is spatially integrated along the optical path; and (2) increasing signal-to-noise ratio is difficult because optical measurement of less than a nanometer order is typically required. To overcome the above difficulties, we have proposed several signal processing methods. In this paper, those methods are introduced with the physical principle of optical sound measurement.

Original languageEnglish
Article number020010
JournalProceedings of Meetings on Acoustics
Volume29
Issue number1
DOIs
Publication statusPublished - 2016 Nov 28
Event172nd Meeting of the Acoustical Society of America - Honolulu, United States
Duration: 2016 Nov 282016 Dec 2

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

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