INVESTIGATION OF THE NEAR-FIELD OF A LOUDSPEAKER USING TOMOGRAPHIC RECONSTRUCTION FROM TV-HOLOGRAPHY MEASUREMENTS

It has previously been shown that a three-dimensional mapping of an ac oustic field's amplitude and phase may be calculated from a set of TV- holography measurements by use of tomographic techniques. In this pape r a thorough mathematical description of this measuring technique is g iven. An increased number of measured projections improves the tomogra phic reconstructions significantly. Techniques for obtaining quantitat ive data for the pressure amplitude of the acoustic field are implemen ted. The technique is demonstrated by measurements of the near field o f a loudspeaker and these measurements are shown to agree well with me asurements obtained with a microphone. (C) 1998 Acoustical Society of America. [S0001-4966(98)02309-1]