Shielded microphone

Details Shielded microphone Shielded microphone

2000-05-25

2004-08-03

Ni, Suhan (Department: 2643)

Electrical audio signal processing systems and devices

Electro-acoustic audio transducer

Housed microphone

C381S189000, C367S174000

Reexamination Certificate

active

06771788

ABSTRACT:

TECHNICAL FIELD
This invention relates to microphone shields, and more particularly to shielding a microphone from environmental effects.
BACKGROUND
High-quality reproduction of sound using available sound recording techniques and equipment is desirable in variety of applications. For example, high-quality, low-noise sound reproductions are important in television and movie industry, radio communication, and wireless telephone devices. Clean voice and dialog reproduction may be desired in the presence of ambient and background noise levels of moderate to high amplitude.
One frequently encountered source of undesirable background noise is caused by air or liquid moving relative to a sound-transducing device, such as a microphone. This type of noise may occur due to environmental conditions. For example, wind may cause distortion of the microphone-sensing membrane. Rain may also cause impact noise as drops of rain land on the microphone. Further, the combination of wind and rain may degrade the structure of the microphone with heat and moisture.
There are several prior art designs that have used open cell foam or cloth, known as a “wind sock” in the recording industry, to reduce the effect of wind noise on microphones. For example, in some embodiments, Drever (U.S. Pat. No. 4,600,077) and McCormick (U.S. Pat. No. 5,808,243). use “wind sock” designs that provide alternate layers of foam
102
and air spaces
104
to improve the microphone
100
performance (see FIG.
1
). However, these techniques are often ineffective in wind conditions above approximately 10 kph.
Electronic filtering techniques have also been used to filter out wind noise. However, electronic filtering also attenuates desired audio frequencies, thereby substantially degrading sound quality.
SUMMARY
In recognition of the above-described problems with the prior designs, the inventors have developed a system that enables relatively low-noise microphone sensing in wind speeds of up to 80 kph, and in some cases, even beyond 80 kph. The inventors recognized that high wind conditions, above a wind speed threshold of about 10 kph, cause pressure imbalances between the front and rear sides of the microphone-sensing element.
The present invention includes a microphone shield system including an impervious elastic membrane stretched over and covering a microphone on at least one side. The impervious elastic membrane is adapted to pass a selected acoustical frequency range. The selected acoustical frequency range excludes a frequency range of noise from environmental effects, such as wind and rain.
The system also includes an opening to allow a plurality of wires to pass through the impervious-elastic membrane. The plurality of wires provides connections to the microphone.
The present invention also includes a method for shielding a microphone from noise created by environmental effects, such as wind and rain. The method includes stretching an impervious elastic membrane over the microphone to form an enclosure, and passing a plurality of wires through the impervious elastic membrane to provide connections to the microphone.
The present invention further includes a wireless telephone device. The device includes housing and communication electronics within the housing. The communication electronics provides transmission and reception of electronic signals. The device also includes a microphone and an impervious elastic membrane stretched over and covering the microphone on at least one side. The impervious elastic membrane is adapted to pass a selected acoustical frequency range, where the selected acoustical frequency range excludes a frequency range of noise from environmental effects, such as wind and rain.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.


REFERENCES:
patent: 4123622 (1978-10-01), MacLeod
patent: 4199667 (1980-04-01), Renner
patent: 4845760 (1989-07-01), Awakowicz et al.
patent: 5613011 (1997-03-01), Chase et al.
patent: 5788516 (1998-08-01), Uggmark
patent: 5808243 (1998-09-01), McCormick et al.
patent: 6018585 (2000-01-01), Akino et al.
patent: 6549636 (2003-04-01), Fujimoto et al.

Affiliated with

Also associated with

Rating

Shielded microphone does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Shielded microphone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shielded microphone will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3314869