Use of acoustic filtering to control the beamwidth of steered microphone arrays
James L. Flanagan · The Journal of the Acoustical Society of America · 1985
Computer-steered microphone arrays provide an attractive sound-transducing means for interactive communication by sizable groups of talkers. But the spatial acuity of arrays typically varies with frequency, exhibiting diminishing beamwidth as frequency increases. Frequency-weighting the receiving elements is one means to mitigate the variation and to achieve more uniform beamwidth over the useful frequency range. Acoustic low-pass filtering, accomplished in the physical housing of the receivers, provides effective and economical modification of beamwidth.