Method and apparatus for generating a speech signal

• US 10,032,461 B2
• Filed: 02/18/2014
• Issued: 07/24/2018
• Est. Priority Date: 02/26/2013
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Srinivasan, Sriram
• Primary Examiner(s): Colucci, Michael
• Application Number:
  US14/766,567
• Publication Number:
  US 20150380010A1
• Time in Patent Office: 1,617 Days
• Field of Search: 704500, 704203, 704235, 704230
• CPC Class Codes: G10L 2021/02082 the noise being echo, reverberation of the speech
• CPC Class Codes: G10L 2021/02161 Number of inputs available containing the signal or the noise to be suppressed
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 25/51 for comparison or discrimination
• CPC Class Codes: H04R 1/025 Arrangements for fixing loudspeaker transducers, e.g. in a box, furniture
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2201/023 Transducers incorporated in garment, rucksacks or the like
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

An apparatus includes microphone receivers configured to receive microphone signals from a plurality of microphones. A comparator configured to determine a speech similarity indication indicative of a similarity between the microphone signal and non-reverberant speech for each microphone signal. The determination is in response to a comparison of a property derived from the microphone signal to a reference property for non-reverberant speech. In some embodiments, the comparator is configured to determine the similarity indication by comparing to reference properties for speech samples of a set of non-reverberant speech samples. A generator is configured to generate a speech signal by combining the microphone signals in response to the similarity indications. The apparatus may be distributed over a plurality of devices each containing a microphone, and the approach may determine the most suited microphone for generating the speech signal.

Claims

1. An apparatus for generating a speech signal, the apparatus comprising:

microphone receivers for receiving a plurality of microphone signals from a plurality of microphones;

a processor configured to select a microphone receiver from the microphone receivers based on how much a microphone signal of the microphone signals reaches the selected microphone receiver via a direct path and how much reaches the microphone receiver via reverberant paths by determining, for each microphone signal, a speech similarity indication indicative of a similarity between the microphone signal and a non-reverberant speech signal, the processor being configured to determine the speech similarity indication in response to a comparison of at least one property derived from the microphone signal to at least one reference property for the non-reverberant speech signal; and

a generator configured to generate the speech signal by combining the microphone signals in response to the speech similarity indications,

wherein the processor is further configured to determine the speech similarity indication for a first microphone signal in response to a comparison of at least one property derived from the first microphone signal to reference properties for speech samples of a set of non-reverberant speech samples, and

wherein the non-reverberant speech signal is a speech signal of one other than a user of the apparatus.

2. The apparatus of claim 1 comprising a plurality of separate devices, each device comprising a microphone receiver for receiving at least one microphone signal of the plurality of microphone signals.

3. The apparatus of claim 2 wherein at least a first device of the plurality of separate devices comprises a local comparator for determining a first speech similarity indication for the at least one microphone signal of the first device.

4. The apparatus of claim 3 wherein the generator is implemented in a generator device separate from at least the first device;

and wherein the first device comprises a transmitter for transmitting the first speech similarity indication to the generator device.

5. The apparatus of claim 4 wherein the generator device is configured to receive speech similarity indications from each of the plurality of separate devices, and wherein the generator is configured to generate the speech signal using a subset of microphone signals from the plurality of separate devices, the subset being determined in response to the speech similarity indications received from the plurality of separate devices.

6. The apparatus of claim 5 wherein at least one device of the plurality of separate devices is configured to transmit the at least one microphone signal of the at least one device to the generator device only if the at least one microphone signal of the at least one device is comprised in the subset of microphone signals.

7. The apparatus of claim 5 wherein the generator device comprises a selector configured to determine the subset of microphone signals, and a transmitter for transmitting an indication of the subset to at least one of the plurality of separate devices.

8. The apparatus of claim 1 wherein the speech samples of the set of non-reverberating speech samples are represented by parameters for a non-reverberating speech model.

9. The apparatus of claim 8 wherein the processor is configured to determine a first reference property for a first speech sample of the set of non-reverberating speech samples from a speech sample signal generated by evaluating the non-reverberating speech model using the parameters for the first speech sample, and to determine the speech similarity indication for a first microphone signal of the plurality of microphone signals in response to a comparison of the property derived from the first microphone signal and the first reference property.

10. The apparatus of claim 1 wherein the processor is configured to decompose the first microphone signal of the plurality of microphone signals into a set of basis signal vectors;

and to determine the speech similarity indication for the first microphone signal in response to a property of the set of basis signal vectors.

11. The apparatus of claim 1 wherein the processor is configured to determine the speech similarity indications for each segment of a plurality of segments of the speech signal, and the generator is configured to determine combination parameters for each segment to control how the speech signal is generated from the microphone signals.

12. The apparatus of claim 9 wherein the generator is configured to determine combination parameters for one segment in response to similarity indications of at least one previous segment.

13. The apparatus of claim 1 wherein the generator is configured to select a subset of the microphone signals to combine in response to the similarity indications.

14. A method of generating a speech signal, the method comprising acts of:

receiving microphone signals from a plurality of microphones;

selecting a microphone from the plurality of microphones based on how much a microphone signal of the microphone signals reaches the selected microphone via a direct path and how much reaches the microphone via reverberant paths, by determining, for each microphone signal, a speech similarity indication indicative of a similarity between the microphone signal and a non-reverberant speech signal, the speech similarity indication being determined in response to a comparison of at least one property derived from the microphone signal to at least one reference property for non-reverberant speech signal; and

generating the speech signal by combining the microphone signals in response to the speech similarity indications,

determining the speech similarity indication for a first microphone signal in response to a comparison of at least one property derived from the first microphone signal to reference properties for speech samples of a set of non-reverberant speech samples, and

wherein the non-reverberant speech signal is a speech signal of one other than a user of the apparatus.

15. The method of claim 14, wherein the identifying act includes acts of:

decomposing a first microphone signal of the plurality of microphone signals into a set of basis signal vectors; and

determining the speech similarity indication for the first microphone signal in response to a property of the set of basis signal vectors.