Multi-membrane microphone for high-amplitude audio capture

• US 10,212,511 B2
• Filed: 07/24/2013
• Issued: 02/19/2019
• Est. Priority Date: 01/20/2009
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Phelps, Andrew Duncan, Suvanto, Mikko Veli Aimo
• Primary Examiner(s): Maung, Thomas
• Assistant Examiner(s): Zhu, Qin
• Application Number:
  US13/949,422
• Publication Number:
  US 20130308797A1
• Time in Patent Office: 2,036 Days
• Field of Search: None
• CPC Class Codes: H04M 1/035 Improving the acoustic characteristics by means of constructional features of the housing, e.g. ribs, walls, resonating chambers or cavities
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 2430/01 Aspects of volume control, not necessarily automatic, in sound systems
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

Disclosed herein are apparatus, method, and computer program product whereby a device receives an acoustic signal. In response to the received acoustic signal, the device outputs electrical signals from a first input audio transducer and a second input audio transducer. The second input audio transducer is less sensitive than the first input audio transducer.

Claims

1. A method comprising:

receiving an acoustic signal;

in response to receiving the acoustic signal, outputting first electrical signals from a first input audio transducer and second electrical signals from a second input audio transducer, where the second input audio transducer is less sensitive than the first input audio transducer;

where a difference in sensitivity of the first input audio transducer relative to sensitivity of the second input audio transducer produces the first electrical signals different from the second electrical signals which is due, at least in part, to at least one of;

a physical configuration of a first membrane member of the first input audio transducer being different relative to a physical configuration of a second membrane member of the second input audio transducer, and

when the first and second transducers are stationary, a capacitive gap between the second input audio transducer and a back-plate of a substrate over which the second input audio transducer is mounted is different relative to a capacitive gap between the first input audio transducer and the back-plate of the substrate over which the first input audio transducer is mounted,

where the first input audio transducer has a first maximum sound pressure level threshold, where the second input audio transducer has a second maximum sound pressure level threshold, and where the second maximum sound pressure level threshold is lower than the first maximum sound pressure level threshold,

where first data corresponding to the first electrical signals output from the first input audio transducer and second data corresponding to the second electrical signals output from the second input audio transducer are transmitted in a pulse density modulation stream with the first data being asserted on a first clock edge and the second data being asserted on a different second clock edge.

2. The method as in claim 1 where the difference in the sensitivity of the first input audio transducer relative to the sensitivity of the second input audio transducer is due, at least in part, to the second membrane member being at least partially thicker and/or stiffer relative to the first membrane member.

3. The method as in claim 1 where the first clock edge is a falling clock edge.

4. The method as in claim 1 where the different second clock edge is a rising clock edge.

5. The method as in claim 1 where the first electrical signals and the second electrical signals are transmitted to an analog to digital converter and converted into the first data and the second data.

6. The method as in claim 1 where the analog to digital converter is a sigma delta modulator which outputs the pulse density modulation stream having both the first and second data.

7. The method as in claim 1 where the first electrical signals and the second electrical signals are transmitted to an analog to digital converter and converted into the first data and the second data.

8. The method as in claim 7 where the analog to digital converter is a sigma delta modulator which outputs the pulse density modulation stream having both the first and second data.

9. A method comprising:

receiving an acoustic signal;

in response to receiving the acoustic signal, outputting first electrical signals from a first input audio transducer and second electrical signals from a second input audio transducer, where the second input audio transducer is less sensitive than the first input audio transducer based, at least in part, upon the first input audio transducer comprising a first membrane member to provide a first sensitivity of the first input audio transducer which is different from a second sensitivity of the second input audio transducer, where the second input audio transducer comprises a second membrane member which has a different physical configuration relative to the first membrane member; and

where first data corresponding to the first electrical signals output from the first input audio transducer and second data corresponding to the second electrical signals output from the second input audio transducer are transmitted in a pulse density modulation stream with the first data being asserted on a first clock edge and the second data being asserted on a different second clock edge,

where the first input audio transducer has a first maximum sound pressure level threshold, where the second input audio transducer has a second maximum sound pressure level threshold, and where the second maximum sound pressure level threshold is lower than the first maximum sound pressure level threshold allowing for a higher sound pressure level without saturation than the first input audio transducer.

10. The method as in claim 9 where a difference in the second sensitivity of the second input transducer versus the first sensitivity of the first input transducer is due, at least in part, to the physical configuration of the second membrane member of the second input audio transducer being at least partially thicker and/or stiffer relative to the physical configuration of the first membrane member of the first input audio transducer.

11. The method as in claim 9 where a difference in the second sensitivity of the second input audio transducer relative to the first sensitivity of the first audio input transducer is due, at least in part, to

when the first and second input audio transducers are stationary, a first capacitive gap between the first input audio transducer and a back-plate of a substrate being different relative to a second capacitive gap between the second input audio transducer and the back-plate of the substrate.

12. The method as in claim 9 where the first clock edge is a falling clock edge.

13. The method as in claim 9 where the different second clock edge is a rising clock edge.

14. The method as in claim 9 where the first electrical signals and the second electrical signals are transmitted to an analog to digital converter and converted into the first data and the second data.

15. The method as in claim 14 where the analog to digital converter is a sigma delta modulator which outputs the pulse density modulation stream having both the first and second data.

16. An apparatus comprising:

a substrate;

a first input audio transducer mounted over the substrate, where the first input audio transducer is configured to output first electrical signals based upon an acoustic signal;

a second input audio transducer mounted over the substrate, where the second input audio transducer is configured to output second electrical signals based upon the acoustic signal, where the second input audio transducer is less sensitive than the first input audio transducer; and

where a difference in the sensitivity of the first input audio transducer versus the second input transducer is due, at least in part, to a physical configuration of a first membrane member of the first input audio transducer being different relative to a physical configuration of a second membrane member of the second input audio transducer, where first data corresponding to the first electrical signals output from the first input audio transducer and second data corresponding to the second electrical signals output from the second input audio transducer are transmitted in a pulse density modulation stream with the first data being asserted on a first clock edge and the second data being asserted on a second clock edge, where the first input audio transducer has a first maximum sound pressure level threshold, where the second input audio transducer has a second maximum sound pressure level threshold, and where the second maximum sound pressure level threshold is lower than the first maximum sound pressure level threshold.

17. The apparatus as in claim 16 where the apparatus is a mobile communication device which comprises electronic circuitry including at least one printed wiring board, at least one processor, at least one memory having software, a transmitter and a receiver, and an electronic display.

18. The apparatus as in claim 16 where the difference in the sensitivity of the first input audio transceiver relative to the sensitivity of the second input transducer is due, at least in part, to the second membrane member being at least partially thicker and/or stiffer relative to the first membrane member.

19. The apparatus as in claim 16 where the difference in the sensitivity of the first input audio transducer relative to the second input audio transducer is due, at least in part, to a capacitive gap between the first input audio transducer and a back-plate of the substrate being different than a capacitive gap between the second input audio transducer and the back-plate of the substrate.

20. An apparatus comprising:

a substrate;

a first input audio transducer mounted over the substrate, where the first input audio transducer is configured to output first electrical signals based upon an acoustic signal;

a second input audio transducer mounted over the substrate, where the second input audio transducer is configured to output second electrical signals based upon the acoustic signal, where the second input audio transducer is less sensitive than the first input audio transducer; and

where first data corresponding to the first electrical signals output from the first input audio transducer and second data corresponding to the second electrical signals output from the second input audio transducer are transmitted in a pulse density modulation stream with the first data being asserted on a first clock edge and the second data being asserted on a second clock edge,

where a difference between a first sensitivity of the first input transducer relative to a different second sensitivity of the second input transducer is due, at least in part, to at least one of;

a physical configuration of a first membrane member of the first input audio transducer being different relative to a physical configuration of a second membrane member of the second input audio transducer, and

a capacitive gap between the first input audio transducer and a back-plate of the substrate being different relative to a capacitive gap between the second input audio transducer and the back-plate of the substrate,

where the first input audio transducer has a first maximum sound pressure level threshold, where the second input audio transducer has a second maximum sound pressure level threshold, and where the second maximum sound pressure level threshold is lower than the first maximum sound pressure level threshold.