Microphone disruption apparatus and method
An apparatus for use with an electronic device having a microphone. The apparatus comprises a structure configured to detachably couple to the device, and a generator supported by the structure. The generator is configured to generate a force that acts on the microphone and renders the microphone unresponsive to voice sounds.
1. An apparatus for use with an electronic device having a microphone, the apparatus comprising:
a structure configured to detachably couple to the device;
a plenum supported by the structure and configured to fluidly couple to the microphone; and
a generator supported by the structure and fluidly coupled to the plenum, the generator configured to deliver a modulated flow of air to the plenum that acts on a diaphragm of the microphone and renders the microphone unresponsive to voice sounds.
2. The apparatus of claim 1 , wherein the structure comprises a cover or a sleeve configured to detachably couple to the device.
3. The apparatus of claim 1 , wherein the modulated flow of air delivered by the generator causes clipping of the microphone.
4. The apparatus of claim 1 , wherein:
the diaphragm has an excursion limit; and
the modulated flow of air delivered by the generator causes the diaphragm to move to or near the excursion limit.
5. The apparatus of claim 1 , wherein the generator comprises a piston generator.
6. The apparatus of claim 1 , wherein the generator comprises a vane pump.
7. The apparatus of claim 1 , wherein the generator comprises a ducted fan blower.
8. The apparatus of claim 1 , further comprising:
a first auxiliary microphone supported by the structure and configured to receive voice sounds during a time in which the generator is active and the microphone of the device is rendered unresponsive to voice sounds.
9. The apparatus of claim 8 , further comprising vibration absorbing material disposed between the generator and one or both of the first auxiliary microphone and a portion of the structure to which the generator is mounted.
10. The apparatus of claim 8 , further comprising:
a second auxiliary microphone supported by the structure, the second auxiliary microphone responsive to mechanical noise resulting from operation of the generator and substantially unresponsive to the voice sounds received by the microphone of the electronic device;
wherein a signal produced by the second auxiliary microphone can be used to cancel the mechanical noise from a signal produced by the first auxiliary microphone.
11. The apparatus of claim 1 , comprising:
a plurality of plenums each configured to fluidly couple to one of a plurality of microphones of the device;
wherein the generator is configured to deliver a modulated flow of air to each of the plenums that acts on a diaphragm of the microphones and renders the microphones unresponsive to voice sounds.
12. An apparatus for use with an electronic device having a microphone, the apparatus comprising:
a structure configured to detachably couple to the device;
a plenum supported by the structure and configured to fluidly couple to the microphone; and
a generator supported by the structure and fluidly coupled to the plenum, the generator comprising:
an electromagnet coil; and
a piston comprising a permanent magnet and configured to translate axially in an oscillatory manner in response to an electromagnetic field produced by the electromagnetic coil;
wherein oscillatory movement of the piston produces a modulated flow of air delivered to the plenum that acts on a diaphragm of the microphone and renders the microphone unresponsive to voice sounds.
13. The apparatus of claim 12 , wherein:
the generator comprises a rebound arrangement situated proximate each end of the piston; and
each of the rebound arrangements is configured to produce a force that serves to redirect the piston.
14. The apparatus of claim 12 , wherein:
the generator comprises a spool having a bore;
the electromagnet coil is wound around the spool; and
the piston is configured to move axially within the bore of the spool in response to the electromagnetic field.
15. The apparatus of claim 12 , wherein the generator comprises a first outlet port proximate a first end of the piston and a second output port proximate a second end of the piston.
16. The apparatus of claim 12 , wherein the piston comprises a first portion comprising the permanent magnet and a second portion comprising non-magnetic material.
17. The apparatus of claim 12 , wherein the generator comprises a pressure cell comprising a compliant membrane and an outlet port, the membrane subject to displacement in response to forcible contact with the piston.
18. The apparatus of claim 12 , comprising:
a plurality of plenums each configured to fluidly couple to one of a plurality of microphones of the device;
wherein the generator is configured to deliver a modulated flow of air to each of the plenums that acts on a diaphragm of the microphones and renders the microphones unresponsive to voice sounds.
19. A method involving a microphone of an electronic device, the method comprising:
generating, at a cover or a sleeve detachably coupled to an external surface of the device, a modulated flow of air that is directed at the microphone; and
rendering the microphone unresponsive to voice sounds by the modulated flow of air acting on the microphone.
20. The method of claim 19 , further comprising delivering the modulated flow of air to the microphone via a plenum.