Back to results
US 7,120,262 B2Granted
Directional-microphone and method for signal processing in same
AssigneeSiemens Aktiengesellschaft
InventorStefano Ambrosius Klinke
Life of this patent
Estimating the term…
Abstract
Provided is a directional-microphone system, as well as a method for signal processing in such a directional-microphone system, wherein a particularly controllable second-order directional-microphone pattern is ensured while the number of figure-of-eight microphones required to generate such pattern is minimized.
Claims10
A directional-microphone system, comprising:
- a first figure-of-eight microphone and a second figure-of-eight microphone particularly arranged such that a major axis of the first figure-of-eight microphone and a major axis of the second figure-of-eight microphone extend in parallel with a first axis;
- a third figure-of-eight microphone and a fourth figure-of-eight microphone particularly arranged such that a major axis of the third figure-of-eight microphone and a major axis of the fourth figure-of-eight microphone extend in parallel with a second axis, the first axis and the second axis being orthogonal to one another;
- a fifth figure-of-eight microphone particularly arranged such that a major axis of the fifth figure-of-eight microphone extends orthogonal to the major axis of the first figure-of-eight microphone;
- and
- a device for phase shifting connected downstream of two of the figure-of-eight microphones whose respective major axes extend orthogonal to one another.
2 more elements
A method for signal processing in a directional-microphone system, the method comprising the steps of:
- driving a first arrangement of two figure-of-eight microphones with mutually parallel major axes such that a first received signal proportional to A*cos2(α) is obtained;
- driving a second arrangement of two figure-of-eight microphones with mutually parallel major axes such that a second received signal proportional to B*sin2(α) is obtained;
- driving a fifth figure-of-eight microphone with a major axis orthogonal to a figure-of-eight microphone of one of the first arrangement and the second arrangement such that a third received signal proportional to C*cos(α)*sin(α) is obtained;
- driving a figure-of-eight microphone of the first arrangement and a figure-of-eight microphone of the second arrangement, the major axes of which extend orthogonal to one another, such that a fourth received signal proportional to D*cos(α)+E*sin(α) is obtained;
- and
- phase-shifting the fourth received signal by 90° and linearly combining it with a sum of the first received signal, the second received signal and the third received signal, in each case weighted with factors, setting
- A:=cos2(φ)
- B:=sin2(φ)
- C:=−2 cos(φ)*sin(φ)
- D:=cos(φ)
- E:=−sin(φ), and where
- α:=a direction from which a sound wave is coming
- φ:=desired direction of a major lobe of the directional-microphone system.
10 more elements
Dependencies are inferred from the claim text.