Noise cancellation headset

• US 5,182,774 A
• Filed: 07/20/1990
• Issued: 01/26/1993
• Est. Priority Date: 07/20/1990
• Status: Expired due to Fees

• Current Assignee: Telex Communications Incorporated (Robert Bosch GmbH)
• Original Assignee: Telex Communications Incorporated (Robert Bosch GmbH)
• Inventors: Bourk, Terrance R.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Cumming, William
• Application Number:
  US07/555,990
• Time in Patent Office: 921 Days
• Field of Search: 379/419, 379/428, 379/430, 381/71, 381/72, 381/74, 381/96, 381/150, 381/182, 381/183, 381/187
• US Class Current: 381/71.6
• CPC Class Codes: A61F 11/145 electric, e.g. for active noise reduction
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06

Abstract

A headset for acoustic reproduction of an electronic signal which electronic signal is representative of the summation of a desired audio signal and an anti-noise signal. The headset includes a headband, an earcup mounted to the headband, a driver mounted within the earcup which receives and acoustically reproduces the electronic signal, a directional microphone which detects and transduces the acoustical pressure within the earcup cavity, means for generating the anti-noise signal from the microphone signal, and a positioning member for mounting the microphone to the earcup in a position so that the microphone is acoustically coupled to the driver. The microphone is oriented so that its vented or open face is pointing towards the driver. If the driver is provided with an inner dome portion and an outer annulus portion the microphone is positioned by its attachment to a grille plate extending across the driver, the microphone being mounted to the grille plate on a side opposite the driver. The grille plate includes a plurality of apertures, at least one of which is positioned proximate the center of the driver with the microphone mounted across that aperture so that the microphone is acoustically coupled to the dome portion and acoustically isolated from the outer annulus portion.

Claims

1. A headset for acoustic reproduction of an electronic anti-noise signal, the headset comprising:

a headband;

a cup, mounted to the headband;

a driver mounted within the cup, which receives and acoustically reproduces the electronic signal;

a microphone, having a directional sensing surface which detects and transduces acoustic pressure within the cup to a corresponding microphone electrical signal;

means for generating the anti-noise signal from the microphone signal; and

portioning means for mounting the microphone to the cup and for centering the microphone over the driver with the directional sensing surface oriented substantially directly toward the driver the positioning means comprising a grille plate mounted to the cup across the driver, the microphone being mounted to the grille plate.

2. The headset of claim 1, wherein the grille plate includes a plurality of apertures therethrough, at least one aperture being positioned proximate the center of the driver and the microphone being mounted across such aperture.

3. The headset of claim 2, wherein the microphone is mounted so that the directional sensing surface is pointing through the at least one aperture toward the driver.

4. The headset of claim 3, wherein the distance separating the microphone from the driver is less than about one quarter (1/4) of an inch.

5. The headset of claim 2, wherein the apertures are round.

6. The headset of claim 1, further comprising mounting bracket mounted in the cup, the driver being mounted on the mounting bracket.

7. The headset of claim 6, wherein the mounting bracket defines a bracket cavity within the cup and wherein the driver is mounted within the bracket cavity.

8. The headset of claim 7, wherein the mounting bracket is secured within the cup thereby defining an earcup cavity so that the volume of the earcup cavity is sealed from the air outside of the cup.

9. The headset of claim 1, further comprising a foam layer attached to the cup covering the driver and the microphone.

10. The headset of claim 1, further comprising a soft cushion mounted on the outer edge of the cup so that when the cup is pressed on the head of a user, the cushion is between the cup and the user'"'"'s head.

11. The headset of claim 1, further comprising a second cup, mounted to the headband;

a second driver, mounted within the second cup, which receives and acoustically reproduces the electronic signal;

a second microphone having a directional sensing surface,; and

second positioning means for mounting the second microphone to the second cup and for centering the second microphone over the second driver, wherein the directional sensing surface is oriented directly toward the second driver.

12. The headset of claim 1, including means for summing a desired audio communications signal with the anti-noise signal before providing the anti-noise signal to the driver so that the sum of the desired audio signal and the anti-noise signal and the anti-noise signal is provided to the driver.

13. The headset of claim 12, further comprising a plurality of cascaded filters for accentuating a desired frequency range.

14. The headset of claim 13, wherein the cascaded filters includes a high pass filter for filtering out those components of the electronic signal having frequencies below a first frequency, and a low pass filter for filtering out those components of the electronic signal having frequencies above a second frequency.

15. The headset of claim 14, further comprising a mid-range filter for providing additional attenuation to those components of the electronic signal having frequencies falling between a third and fourth frequency.

16. The headset of claim 15, wherein the first frequency is 17 Hz, the second frequency is 8 kHz, the third frequency is 600 Hz and the forth frequency is 1200 Hz.

17. The headset of claim 7, wherein the driver is sealingly mounted within the mounting bracket.

18. A headset for acoustic reproduction of an electronic anti-noise signal, the headset comprising:

a headband;

a cup, mounted to the headband;

a mounting bracket mounted in the cup, the mounting bracket defining a bracket cavity within the cup on one side of the bracket, the mounting bracket being secured within the cup to define with the cup an earcup cavity so that the volume of the earcup cavity is sealed from air outside of the cup;

the mounting bracket further containing a bore, thereby providing fluid communication between the earcup cavity and the bracket cavity;

a driver, which receives and acoustically reproduces the electronic signal, mounted on the mounting bracket with in the bracket cavity;

a microphone, having a directional sensing surface which detects and transduces acoustic pressure within the cup to a corresponding microphone electrical signal;

means for generating the anti-noise signal for the microphone signal;

positioning means for mounting the microphone to the cup and for centering the microphone over the driver with the directional sensing surface oriented substantially directly toward the driver.

19. The headset of claim 18, further comprising a cloth attached to the mounting bracket to cover the bore.

20. A headset for acoustic reproduction of an electronic signal which electronic signal is representative of the summation of an audio signal and an anti-noise signal, the headset comprising:

a headband;

a cup, mounted to the headband;

a driver, mounted within the cup, which receives and acoustically reproduces the electronic signal;

a directional microphone having a vented face;

means for generating the anti-noise signal from the microphone signal;

a grille plate mounted to the cup across the driver, the grille plate including a plurality of apertures therethrough, at least one such aperture being positioned proximate the center of the driver, the microphone being mounted to the grille plate with the vented face of the microphone being mounted across such central aperture with the vented face pointing therethrough oriented substantially directly toward the driver.

21. A headset for acoustic reproduction of an electronic signal which electronic signal is representative of the summation of an audio signal and an anti-noise signal, the headset comprising:

a headband;

a cup, mounted to the headband;

a driver, mounted within the cup, which receives and acoustically reproduces the electronic signal, the driver having an inner dome portion and an outer annulus portion;

a directional microphone having a vented face;

means for generating the anti-noise signal from the microphone signal; and

positioning means for mounting the microphone to the cup so that the microphone is acoustically coupled to the dome portion and isolated from the outer annulus portion, the positioning means comprising a grille plate mounted to the cup across the driver, the microphone being mounted to the grille plate on a side opposite the driver.

22. The headset of claim 21, wherein the grille plate includes a plurality of apertures therethrough, wherein at least one aperture is positioned proximate the center of the driver and wherein the microphone is mounted across the at least one aperture.

23. The headset of claim 22, wherein the microphone is mounted so that the vented face is pointing through the at least one aperture.