A polyphonic acoustic vortex and its complementary chords

Wilson, C. and Padgett, M.J. (2010) A polyphonic acoustic vortex and its complementary chords. New Journal of Physics, 12(2), 023018. (doi: 10.1088/1367-2630/12/2/023018)




Using an annular phased array of eight loudspeakers, we generate sound beams that simultaneously contain phase singularities at a number of different frequencies. These frequencies correspond to different musical notes and the singularities can be set to overlap along the beam axis, creating a polyphonic acoustic vortex. Perturbing the drive amplitudes of the speakers means that the singularities no longer overlap, each note being nulled at a slightly different lateral position, where the volume of the other notes is now nonzero. The remaining notes form a tri-note chord. We contrast this acoustic phenomenon to the optical case where the perturbation of a white light vortex leads to a spectral spatial distribution.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Padgett, Professor Miles and Wilson, Mr Christopher
Authors: Wilson, C., and Padgett, M.J.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:New Journal of Physics
Journal Abbr.:New J. Phys.
ISSN (Online):1367-2630
Published Online:15 February 2010
Copyright Holders:Copyright © 2010 Institute of Physics Publishing Ltd.
First Published:First published in New Journal of Physics 12 (5): 033018
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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