Method and device for separating acoustic signals
First Claim
1. Method of separating acoustic signals from a plurality of sound sources (S1, S2), comprising the following steps:
- disposing two microphones (MIK1, MIK2) at a predefined distance (d) from one another;
picking up the acoustic signals with both microphones (MIK1, MIK2) and generating associated microphone signals (m1, m2); and
separating the acoustic signal of one of the sound sources (S1) from the acoustic signals of the other sound sources (S2) on the basis of the microphone signals (m1, m2),in which the separation step comprises the following steps;
applying a Fourier transform to the microphone signals in order to determine their frequency spectra (M1, M2);
determining the phase difference (φ
) between the two microphone signals (m1, m2) for every frequency component of their frequency spectra (M1, M2);
determining the angle of incidence (θ
) of every acoustic signal allocated to a frequency of the frequency spectra (M1, M2) on the basis of the phase difference (φ
) and the frequency;
generating a signal spectrum (S) of a signal to be output by correlating one of the two frequency spectra (M1, M2) with a filter function (Fθ
0) which is selected so that acoustic signals from an area (γ
3db) around a preferred angle of incidence (θ
0) are amplified relative to acoustic signals from outside this area (γ
3db); and
applying an inverse Fourier transform to the resultant signal spectrum, characterised in that the filter function (Fθ
0) is dependent on the angle of incidence θ and
has a maximum at the preferred angle of incidence (θ
0) when the angle of incidence θ
is varied, and the correlation of the filter function (Fθ
0) with one of the two frequency spectra comprises multiplying the same.
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Abstract
In a method of separating acoustic signals from a plurality of sound sources comprising the following steps: disposing two microphones (MIK1, MIK2) at a predefined distance (d) from one another; picking up the acoustic signals with both microphones (MIK1, MIK2) and generating associated microphone signals (m1, m2); and separating the acoustic signal of one of the sound sources (SI) from the acoustic signals of the other sound sources (S2) on the basis of the microphone output signals (m1, m2), the proposed separation step comprises the following steps: applying a Fourier transform to the microphone output signals in order to determine their frequency spectra (M1, M2); determining the phase difference between the two microphone output signals (m1, m2) for every frequency component of their frequency spectra (M1 , M2); determining the angle of incidence of every acoustic signal allocated to a frequency of the frequency spectra (M1, M2) on the basis of the relative phase angle and the frequency; generating a signal spectrum (5) of a signal to be output by correlating one of the two frequency spectra (M1, M2) with a filter function which is selected so that acoustic signals from an area around a preferred angle of incidence are amplified relative to acoustic signals from outside this area; and applying an inverse Fourier transform to the resultant signal spectrum.
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Citations
9 Claims
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1. Method of separating acoustic signals from a plurality of sound sources (S1, S2), comprising the following steps:
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disposing two microphones (MIK1, MIK2) at a predefined distance (d) from one another; picking up the acoustic signals with both microphones (MIK1, MIK2) and generating associated microphone signals (m1, m2); and separating the acoustic signal of one of the sound sources (S1) from the acoustic signals of the other sound sources (S2) on the basis of the microphone signals (m1, m2), in which the separation step comprises the following steps; applying a Fourier transform to the microphone signals in order to determine their frequency spectra (M1, M2); determining the phase difference (φ
) between the two microphone signals (m1, m2) for every frequency component of their frequency spectra (M1, M2);determining the angle of incidence (θ
) of every acoustic signal allocated to a frequency of the frequency spectra (M1, M2) on the basis of the phase difference (φ
) and the frequency;generating a signal spectrum (S) of a signal to be output by correlating one of the two frequency spectra (M1, M2) with a filter function (Fθ 0 ) which is selected so that acoustic signals from an area (γ
3db) around a preferred angle of incidence (θ
0) are amplified relative to acoustic signals from outside this area (γ
3db); andapplying an inverse Fourier transform to the resultant signal spectrum, characterised in that the filter function (Fθ 0 ) is dependent on the angle of incidence θ and
has a maximum at the preferred angle of incidence (θ
0) when the angle of incidence θ
is varied, and the correlation of the filter function (Fθ0 ) with one of the two frequency spectra comprises multiplying the same. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification