The Energy Flow for a Spherical Acoustic Lens: Experimental Results Avoiding Interference Effects

Document Type

Article

Publication Date

2010

Publication Title

The Journal of the Acoustical Society of America

DOI

10.1121/1.3384845

Abstract

A simple classroom demonstration consists of a weather balloon filled with carbon dioxide, a sound source, and a microphone. Since the speed of sound is slower in carbon dioxide than in air at room temperature and pressure, the balloon acts as a positive spherical acoustic lens. Preliminary experimental results have been presented previously [C. E. Dean and J. P. Braselton, “The energy flow for a spherical acoustic lens: ray and wave methods vs. experiment.,” J. Acoust. Soc. Am. 125, 2627 (2009)]. The possibility of interference effects from the reflection of sound off surfaces was brought up in the ensuing discussion. The current results have been measured in a way that minimizes the effect of interference due to reflections off walls, floor, or other surfaces. © 2010 Acoustical Society of America

Comments

Copyright 2010 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.


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