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)

Abstract

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
• Status: Published
• Refereed: Yes
• 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