An Evaluation Method for Sampling Intervals in Measurements of Sound Pressure Distribution

Abstract

This paper deals with an evaluation method for spatial sampling intervals in the measurement or the calculation of sound pressure distribution. In this method, a sampling coefficient is newly defined as the ratio of a sampling interval to the half-wavelength of the sound in question. On the assumption that the sound pressure distribution along an arbitrary straight spatial line in a sound field can be represented by a one-dimensional spatial coordinate in the line direction, it can be theoretically shown that the spatial sampling interval should be set so as to make the sampling coefficient less than 1. In order to examine the influence of the sampling coefticient, three models of sound sources have been used in experimentation. The sound pressure distribution around each model has been measured and calculated for different sampling coefficients. All the results obtained show that the evaluation method using the sampling coefficient is effective and applicable to actual three-dimensional sound fields.