Direction sensing microphone system using time differential

• US 5,452,363 A
• Filed: 10/12/1993
• Issued: 09/19/1995
• Est. Priority Date: 10/12/1993
• Status: Expired due to Fees

• Current Assignee: Lynn J. Mader
• Original Assignee: Lynn J. Mader
• Inventors: Mader, Lynn J.
• Primary Examiner(s): BRINICH, STEPHEN M
• Application Number:
  US08/134,647
• Time in Patent Office: 707 Days
• Field of Search: 381/92, 367/129
• US Class Current: 381/92
• CPC Class Codes: G01S 3/808 using transducers spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: H04R 1/406 microphones

Abstract

Sound received by a microphone is allowed to travel to the output, such as loudspeakers, only if the sound is coming from a desired direction. A pair of conventional microphone elements are spaced-apart within the microphone and the time it takes for the sound to pass between the two elements is measured and if within a prescribed time, then the microphone is "turned on" so that sound is permitted to reach or be gated to the output. Preferably the desired or acceptable source of the sound is from generally directly in front of the microphone, i.e., where the user of the microphone usually is located so that sound coming in from either side of the user or ambient room noise is blocked from being transferred to the output.

Claims

1. In an audio sound system having multiple microphones feeding into a loudspeaker, a method for distinguishing between sources of sound coming to a single microphone, said method comprising the steps of:

a) placing a pair of non-directional microphone elements in spaced-apart relationship within a single microphone;

b) triggering a timing device with the output of one of said microphone elements to produce a prescribed time signal;

c) then comparing the time of occurrence of the output from the other microphone element to the timing device prescribed time signal; and

d) then blocking the sound received at the microphone from reaching the loudspeaker when the output of the other microphone element occurs outside the prescribed time signal.

2. In an audio sound system having a microphone, an amplifier for amplifying the sound received by the microphone and an audio system output for broadcasting the amplified sound received by the microphone, the improvement comprising:

a) first and second non-directional microphone elements displaced from one another within a single microphone, each of said elements producing a microphone output signal in response to the sound received by the microphone;

b) timing means triggered by a microphone output signal of one of said microphone elements;

c) said timing means producing a timing means output signal at a prescribed time after being triggered;

d) gating means having said timing means output signal as a first input and the microphone output signal from the other of said microphone elements as a second input for controlling the passage of the sound received by the single microphone to the audio system output.