A new laser-driven technique allows remote, non-invasive and rapid mapping of sound fields, which will provide loudspeaker manufacturers with detailed data on which to design their technology.
The technique builds on the laser vibrometer and relies on a phenomenon called the acousto-optic effect. To measure the acoustic output, the laser is positioned to the side of the loudspeaker and rapidly scanned through a series of points in front of the loudspeaker, before being reflected back to the instrument by a retro-reflective mirror.
By measuring the laser as it returns to its source, the technology can rapidly provide spatially distributed phase shift data. This data can then be used to construct an image, or video, of sound propagation around the source, i.e. the loudspeaker.
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