Inertial microphone system

• US 4,006,318 A
• Filed: 04/21/1975
• Issued: 02/01/1977
• Est. Priority Date: 04/21/1975
• Status: Expired due to Term

• Current Assignee: Magnavox Electronic Systems Company
• Original Assignee: DYNA Magnetic Devices Incorporated
• Inventors: Hofer, Alan, Carlisle, Richard W., Sebesta, George J.
• Primary Examiner(s): Cooper, William C.
• Application Number:
  US05/569,996
• Time in Patent Office: 652 Days
• Field of Search: 179/121 C, 179/156 R, 179/121 I, 179/107 BC, 179/182 R
• US Class Current: 381/151
• CPC Class Codes: H04M 1/05 specially adapted for use on head, throat or breast
• CPC Class Codes: H04R 1/46 Special adaptations for use as contact microphones, e.g. on musical instrument, on stethoscope throat mountings H04R1/14

Abstract

An inertial-reaction microphone transducer mounting supported on the wearer'"'"'s head away from the mouth for transmitting speech to the exclusion of ambient. A compliant, radial array of elastomer supporting material presses the transducer gently to the head. The transducer and supporting array may be mounted in a cup covering one ear, or it may be mounted in a capsule having an acoustical labyrinth frequency-selective vent for the neutralization of noise.

Claims

1. A microphone adapted to be worn in contact with the head of a wearer to pick up the speech of the wearer and to severely attenuate ambient sounds, consisting of an inertial reaction transducer, an acoustical enclosure, support means for said transducer, and an acoustical labyrinth, the support means for said transducer including relatively thin compliant suspension means made from rubber-like elastomer material, the support means including a protuberance normally extending outward from the plane of the suspension means but adapted to be deflected inwardly of the acoustical enclosure when said microphone is applied to the head of a wearer, said acoustical labyrinth constituting acoustical filter means for excluding at least high frequency ambient sound.

2. A microphone as set forth in claim 1 in which the compliance of the suspension means is such that a force in the range of between five and fifteen ounces will force the protuberance back to a flush relationship with the face of the surround.

3. A microphone as set forth in claim 1 in which the compliance of the suspension means is of the order of magnitude of 0.9×

10.sup.^-6 cm/dyne.

4. A microphone as set forth in claim 1 in which the compliance of the suspension means is of such order of magnitude that a force of 10 ounces causes the protuberance to retract 3/32 inch.

5. A microphone as set forth in claim 1 further including acoustical filter means in the wall of the enclosure comprising an acoustical labyrinth having at least one acoustical-transmitting tube having a length greater than its diameter.

6. A microphone as set forth in claim 5 in which the acoustical labyrinth is comprised of a disc of foam elastomer retained between walls of rubber-like material each having apertures therein communicating with each other through the foam disc, whereby to transmit a controlled amount of low frequency ambient sound.