Experimental results showing the effects of optimal spacing between elements of a linear microphone array

Stochastic region contraction is applied to an improved field model which includes attenuation due to the source-to-microphone distance, and a new optimal spacing is derived. The performances of equispaced, logarithmically spaced, old-model optimal, and new-model optimal arrays were measured experimentally and are compared to the results predicted from the mathematical model. The shape of the power distribution of the received signal in the near field of the array is verified in general. The differences are due to echoes, background noise, nonideal microphone beam patterns, and other variables that were not included in the model.<<ETX>>