Microphone with acoustic mesh to protect against sudden acoustic shock
A portable electronic device having an outer case having a substantially planar face in which a microphone associated acoustic port is formed. The device also has a micro-electro-mechanical system (MEMS) microphone positioned within the outer case, the MEMS microphone having a diaphragm facing the microphone associated acoustic port. An acoustic mesh is positioned between the front face of the outer case and the diaphragm, the acoustic mesh having a non-linear acoustic resistance so as to minimize an effect of an incoming air burst on the diaphragm. Other embodiments are also described and claimed.
1. A portable electronic device comprising:
an outer case having a substantially planar face in which a microphone associated acoustic port is formed;
a micro-electro-mechanical system (MEMS) microphone positioned within the outer case, the MEMS microphone having a diaphragm facing the microphone associated acoustic port; and
a closed mesh positioned between the substantially planar face of the outer case and the diaphragm, the closed mesh having a non-linear acoustic resistance that is to reduce an effect of an incoming air burst on the diaphragm.
2. The portable electronic device of claim 1 wherein the acoustic resistance of the closed mesh is at least 1000 MKS rayls.
3. The portable electronic device of claim 1 wherein the microphone associated acoustic port is dimensioned to tune an absolute acoustic resistance of the closed mesh.
4. The portable electronic device of claim 1 wherein the closed mesh is a first acoustic mesh, the device further comprising:
a second acoustic mesh positioned over the microphone associated acoustic port.
5. The portable electronic device of claim 3 wherein the absolute acoustic resistance is from 600 MKS rayls to 2000 MKS rayls.
6. The portable electronic device of claim 1 wherein the device is a mobile telephone.
7. A portable electronic device comprising:
an outer case having a substantially planar face in which an acoustic port is formed;
a transducer positioned within the outer case, the transducer having a diaphragm facing the acoustic port; and
an acoustic mesh positioned over the acoustic port, the acoustic mesh comprising a closed mesh material having an acoustic resistance that is to a) reduce an effect of an incoming air burst on the transducer in a non-linear manner and b) present a linear acoustic resistance to speech by a user of the device.
8. The portable electronic device of claim 7 wherein the transducer is a MEMS microphone.
9. The portable electronic device of claim 7 wherein the acoustic port is an acoustic input port and the planar face is a back face of the outer case.
10. The portable electronic device of claim 7 wherein the acoustic mesh is positioned between the diaphragm and the substantially planar face of the outer case.
11. The portable electronic device of claim 7 wherein the closed mesh material comprises substantially no calculable mesh openings on a face of the material.
12. The portable electronic device of claim 7 wherein the acoustic resistance of the acoustic mesh is from 1000 rayls to 5000 rayls.
13. The portable electronic device of claim 7 wherein the acoustic port is dimensioned to tune an absolute acoustic resistance of the acoustic mesh.
14. The portable electronic device of claim 7 wherein the acoustic mesh reduces the effect of the incoming air burst on the diaphragm by causing a greater degree of pressure drop across the acoustic mesh in response to the incoming air burst than non-air burst incoming air.
15. A portable electronic device comprising:
a means for communicating with a far end user, the means for communicating having a means for receiving an incoming sound wave;
a means for converting the sound wave into an electrical signal, the means for converting acoustically coupled to the means for receiving; and
a means for protecting the means for converting from an incoming air burst in a non-linear manner by causing a greater pressure drop in response to the incoming air burst than non-air burst incoming air, wherein the means for protecting comprises a material having substantially no calculable openings on a face of the material.
16. The portable electronic device of claim 15 wherein the means for protecting is one of a closed mesh material or a membrane.
17. A microphone assembly comprising:
a transducer for converting acoustic energy into electrical energy, the transducer having a pressure sensitive diaphragm which vibrates in response to the acoustic energy;
a housing for receiving the transducer therein, the housing having an acoustic input opening for directing the acoustic energy to the diaphragm; and
a closed mesh positioned over the acoustic input opening, the closed mesh having a non-linear acoustic resistance so as to reduce an effect of an incoming air burst on the diaphragm by causing a greater pressure drop across the closed mesh in response to an incoming air burst than a non-air burst.
18. The microphone assembly of claim 17 wherein the transducer is a MEMS microphone.
19. The microphone assembly of claim 17 wherein the closed mesh has an acoustic resistance of at least 1000 rayls.