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US 5,602,962 AGranted
Mobile radio set comprising a speech processing arrangement
AssigneeU.S. Philips Corporation
InventorWalter Kellermann
Life of this patent
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AssigneeU.S. Philips Corporation
InventorWalter Kellermann
Estimating the term…
A speech processing arrangement has at least two microphones for supplying microphone signals formed by speech components and noise components to microphone signal branches that are coupled to an adder device used for forming a sum signal. The microphone signals are delayed and weighted by weight factors in the microphone signal branches. The arrangement includes an evaluation circuit that a) receives the microphone signals, b) estimates the noise components, c) estimates the speech components by forming the difference between one of the microphone signals and the estimated noise component for this microphone signal, d) selects one of the microphone signals as a reference signal which contains a reference noise component and a reference speech component, e) forms speech signal ratios by dividing the estimated speech components by the estimated reference speech component, f) forms noise signal ratios by dividing the powers of the estimated noise components by the power of the estimated reference noise component, and g) determines the weight factors by dividing each speech signal ratio by the associated noise signal ratio. The signal-to-noise ratio corresponds to the ratio of the power of the speech component to the power of the noise component of the sum signal. Because the speech signals are correlated and noise signals are uncorrelated, the sum signal available on the output of the adder device has a reduced noise component yielding improved speech audibility. Real-time computation of the weight factors eliminates any annoying delay during a conversation held using the speech processing arrangement.
A radio set comprising a speech processing arrangement having at least two microphones (M.sub.1, . . . , M.sub.N) for supplying microphone signals (x.sub.1, . . . , x.sub.N) formed by speech components and noise components (s.sub.1, . . . , S.sub.N, n.sub.1, . . . , n.sub.N) to microphone signal branches that are coupled to inputs of an adder device used for forming which forms a sum signal (x), wherein delay means (T.sub.1, . . . , T.sub.N) for delaying the microphone signals (x.sub.1, . . . , x.sub.N) and weighting means for weighting the microphone signals (x.sub.1, . . . , x.sub.N) with weight factors (c.sub.1, . . . , c.sub.N) are included in the microphone signal branches, and an evaluation circuit, said evaluation circuit including:
A speech processing arrangement comprising at least two microphones (M.sub.1, . . . , M.sub.N) used for supplying microphone signals (x.sub.1, . . . , x.sub.N) formed by speech components and noise components (s.sub.1, . . . , s.sub.N, n.sub.1, . . . , n.sub.N) to microphone signal branches which branches are coupled to inputs of an adder device used for forming a sum signal (x), wherein delay means (T.sub.1, . . . , T.sub.N) for delaying the microphone signals (x.sub.1, x.sub.N) and weighting means for weighting the microphone signals (x.sub.1, . . . , x.sub.N) with weight factors (c.sub.1, . . . , c.sub.N) are included in the microphone signal branches, and an evaluation circuit is provided
A method for use in an evaluation circuit which is part of a speech processing arrangement, the speech processing arrangement having at least two microphones which are used for supplying microphone signals formed by speech components and noise components to microphone signal branches which are coupled to inputs of an adder device used for forming a sum signal, wherein delay means for delaying the microphone signals and weighting means for weighting the microphone signals with weight factors are included in the microphone signal branches, the method for use in the evaluation circuit comprising the steps of:
Dependencies are inferred from the claim text.