METHOD OF IDENTIFYING A WIRELESS COMMUNICATION CHANNEL IN A SOUND SYSTEM

• US 20120300958A1
• Filed: 05/22/2012
• Published: 11/29/2012
• Est. Priority Date: 05/23/2011
• Status: Active Grant

• Current Assignee: Oticon A/S (William Demant Fonden)
• Original Assignee: Oticon A/S (William Demant Fonden)
• Inventors: KLEMMENSEN, Bjarne
• Granted Patent: US 9,204,232 B2
• Time in Patent Office: Days
• US Class Current: 381/81
• CPC Class Codes: G09B 21/006 using audible presentation of the information
• CPC Class Codes: G09B 5/04 with audible presentation of the material to be studied sound recording or reproducing G11B
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10
• CPC Class Codes: H04R 2225/51 Aspects of antennas or their circuitry in or for hearing aids
• CPC Class Codes: H04R 2225/61 Aspects relating to mechanical or electronic switches or control elements, e.g. functioning
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 25/407 Circuits for combining signals of a plurality of transducers
• CPC Class Codes: H04R 25/43 Electronic input selection or mixing based on input signal analysis, e.g. mixing or selection between microphone and telecoil or between microphones with different directivity characteristics H04R25/407 takes precedence
• CPC Class Codes: H04R 25/552 Binaural
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils
• CPC Class Codes: H04R 25/558 Remote control, e.g. of amplification, frequency
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 27/02 Amplifying systems for the deaf
• CPC Class Codes: H04R 29/007 for public address systems public address systems per se H04R27/00
• CPC Class Codes: H04R 29/008 Visual indication of individual signal levels visual indication of stereophonic sound image H04S7/40

Abstract

A method of identifies an appropriate wireless communication channel in an audio receiving device, that comprises 1) a wireless receiver receiving an audio signal on a particular transmission channel selected among a predefined number of possible transmission channels, and 2) a microphone for picking up a sound in the environment of the audio receiving device. The method comprises a) selecting a channel as the receiving channel among a predefined number of possible transmission channels; b) analyzing the received signal received and the signal picked up by the microphone; c) determining whether a predefined criterion concerning the degree of similarity of the received signal and the signal picked up by the microphone is fulfilled; d) KEEPING the channel as the receiving channel, if the predefined criterion is fulfilled; and e) CHANGING the receiving channel to another channel if the predefined criterion is NOT fulfilled.

Claims

1. A method of identifying an appropriate wireless communication channel in an audio receiving device, the audio receiving device comprising

a wireless receiver for receiving an audio signal on a particular transmission channel selected among a predefined number of possible transmission channels, and

a microphone for picking up a sound in the environment of the audio receiving device, and for converting the sound to an electric input signal,

wherein the method comprises

selecting a channel as the receiving channel in the wireless receiver of the audio receiving device among said predefined number of possible transmission channels;

analyzing in the audio receiving device the signal received by the wireless receiver via the receiving channel and the signal picked up by the microphone;

determining in the audio receiving device whether a predefined criterion concerning the degree of similarity of the signal received by the wireless receiver and the signal picked up by the microphone is fulfilled;

KEEPING the channel as the receiving channel, if said predefined criterion is fulfilled; and

CHANGING the receiving channel to another channel selected among said predefined number of possible transmission channels, if said predefined criterion is NOT fulfilled.

2. A method according to claim 1 wherein the predefined criterion concerning the degree of similarity of two signals relates to an estimate of the correlation between the two signals.

3. A method according to claim 2 wherein a correlation measurement is performed over a predefined time, e.g. 20 s or less.

4. A method according to claim 3 wherein the correlation measurement time and/or the number of correlation measurements performed before deciding on the current correlation is/are based on a (target) signal to noise ratio.

5. A method according to claim 2 wherein an estimate of a correlation between the two signals is based on parts of the signals in question, e.g. an envelope.

6. A method according to claim 2 wherein an estimate of a correlation between the two signals is based on voice detection in the respective signals.

7. A method according to claim 2 wherein an estimate of a correlation between the two signals is determined in one or more particular sub-frequency ranges or bands of the total frequency range of the respective signals.

8. A method according to claim 1 comprising, generating an activity control signal indicative of whether the currently selected channel is active or not.

9. A method according to claim 8 comprising, changing to another channel selected among said predefined number of possible transmission channels in case the activity control signal indicates that the currently selected channel is not active.

10. A method according to claim 1 wherein the method is executed when the audio receiving device is brought into a specific mode of operation, either automatically, and/or via a user interface, and/or at the request of an external device and/or when a currently used channel is no longer active.

23. A data processing system comprising a processor and program code means for causing the processor to perform the steps of the method of claim 1.

11. An audio receiving device comprising

a wireless receiver for receiving an audio signal on a particular transmission channel selected among a predefined number of possible transmission channels, and

a microphone for picking up a sound in the environment of the audio receiving device, and for converting the sound to an electric input signal,

a channel selection unit for selecting a receiving channel in the wireless receiver of the listening device among said predefined number of possible transmission channels;

an analyzing unit for analyzing the signal received by the wireless receiver and the signal picked up by the microphone, and for determining whether a predefined criterion concerning the degree of similarity of the two signals is fulfilled;

the audio receiving device being adapted to keeping the receiving channel, if the predefined criterion IS fulfilled; and

to changing the receiving channel to another channel selected among said predefined number of possible transmission channels, if the predefined criterion is NOT fulfilled.

12. An audio receiving device according to claim 11 comprising an indicator for indicating when a receiving channel has been identified, e.g. a light issuing device, such as an LED.

13. An audio receiving device according to claim 11, wherein the microphone is specifically adapted to provide an appropriate signal for channel selection.

14. An audio receiving device according to claim 11 adapted to be detachably attached to another device.

15. An audio receiving device according to claim 11 comprising a voice detector for determining whether or not the electric input signal comprises a voice signal at a given point in time.

16. An audio receiving device according to claim 15 adapted to provide that a correlation measurement is only initiated, if a voice is detected in the signal picked up by the microphone.

17. An audio receiving device according to claim 11 adapted to identify a receiving channel based on a specific test signal issued by an audio source and transmitted by a corresponding audio transmitting device on the relevant transmission channel.

18. An audio receiving device according to claim 11 wherein the wireless receiver comprises an activity control unit adapted to generate an activity control signal indicative of whether the selected channel is active or not.

19. A listening device comprising an audio receiving device according to claim 11.

20. A listening device according to claim 19 comprising a hearing instrument, a headset, an ear phone, an active ear protection device, or a combination thereof.

21. A sound system comprising

an audio source device for generating or picking up an audio signal;

and

an audio transmitting device for generating a wireless signal comprising a representation of said audio signal and transmitting the wireless signal on a particular transmission channel among a predefined number of possible transmission channels, and

an audio receiving device according to claim 11.

22. A sound system according to claim 21 comprising a multitude of listening devices that each comprise:

a wireless receiver for receiving an audio signal on a particular transmission channel selected among a predefined number of possible transmission channels, and

a microphone for picking up a sound in the environment of the audio receiving device, and for converting the sound to an electric input signal,

a channel selection unit for selecting a receiving channel in the wireless receiver of the listening device among said predefined number of possible transmission channels;

an analyzing unit for analyzing the signal received by the wireless receiver and the signal picked up by the microphone, and for determining whether a predefined criterion concerning the degree of similarity of the two signals is fulfilled;

the audio receiving device being adapted to keeping the receiving channel, if the predefined criterion IS fulfilled; and

to changing the receiving channel to another channel selected among said predefined number of possible transmission channels, if the predefined criterion is NOT fulfilled.

said predefined number of possible transmission channels, if the predefined criterion is NOT fulfilled.