A microphone housing improves the broadband noise canceling performance of
an active noise canceling microphone system while also ensuring improved
speech transmission through the system. First and second microphone
elements are selected each having a diameter "d" and a thickness "t". The
two microphone elements are aligned axially with the back surfaces in
contact and secured in an axially aligned cylindrical cavity within a
cylindrically shaped housing. The cylindrically shaped housing has an
outside diameter "D," an interior cavity of diameter of "d," and a height
"2t". The housing is exposed to an environment comprising both speech and
noise. The first microphone element is adapted to receive a signal having
both voice and noise components, while the second microphone element is
adapted to receive a signal that is predominantly noise. A controller
processes signals from the first microphone element and the second
microphone element. The values of D and d are selected so to obtain a
ratio of D over d between 1 and about 2.4 or a near field power
difference of the first microphone signal and the second microphone
signal between 8 dB and 11 dB. In the event the near field power
difference is more than 11 dB, the outside diameter of the microphone
housing "D" is reduced. In the event the near field power difference is
less than 8 dB, the outside diameter of the microphone housing "D" is
increased.