A close-talking pressure-type microphone is an
acoustic transducer which is intended for use in close
proximity to the lips of the talker and is either
hand-held or boom-mounted. Various types of microphones
are currently used for close-talking applications.
These include carbon, dynamic, magnetic,
piezoelectric, electrostrictive and condenser types.
Each of these microphones has only one side of its
diaphragm exposed to sound waves, and its electric
output substantially corresponds to the instantaneous
sound pressure of the impressed sound wave.
Since a close-talking microphone is used in the
near sound field produced by a person's mouth, it is
necessary when measuring the performance of such
microphones to utilize a sound source which approximates
the characteristics of the human sound generator.