a miniature microphone comprising a diaphragm compliantly suspended over an enclosed air volume having a vent port is provided , wherein an effective stiffness of the diaphragm with respect to displacement by acoustic vibrations is controlled principally by the enclosed air volume and the port . the microphone may be formed using silicon microfabrication techniques and has sensitivity to sound pressure substantially unrelated to the size of the diaphragm over a broad range of realistic sizes . the diaphragm is rotatively suspend for movement through an arc in response to acoustic vibrations , for example by beams or tabs , and has a surrounding perimeter slit separating the diaphragm from its support structure . the air volume behind the diaphragm provides a restoring spring force for the diaphragm . the microphone &# 39 ; s sensitivity is related to the air volume , perimeter slit , and stiffness of the diaphragm and its mechanical supports , and not the area of the diaphragm .