Method of identifying a wireless communication channel in a sound system

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.

1 . An audio receiving device for wirelessly receiving audio communication from a wireless broadcaster over an unknown radio channel among a predefined number of possible radio channels, the audio receiving device comprising:
 a microphone for picking up an audio input signal or an audio signal derived from the audio input signal in the environment of the audio receiving device, the microphone converting the picked up signal to an electrical microphone output signal;   a channel selection unit configured to select a radio channel as a candidate of the unknown radio channel in a wireless receiver of the audio listening device among said predefined number of possible radio channels;   the wireless receiver configured to receive an electric signal on the channel selected by the channel selection unit among the predefined number of possible radio channels; and   an analyzing unit configured to analyze the electric signal received by the wireless receiver and the electrical microphone output signal from the microphone of the audio receiving device, and configured to determine whether a predefined criterion of a degree of similarity of the two signals is fulfilled, wherein   the channel selection unit is configured to keep the selected radio channel as the receiving channel, if the predefined criterion is fulfilled, and configured to select another channel from among said predefined number of possible radio channels as the candidate of the unknown radio channel, if the predefined criterion is not fulfilled.   
     
     
         2 . The audio receiving device 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 . The audio receiving device according to  claim 2 , wherein
 the analyzing unit is configured to perform a correlation measurement over a predefined time.   
     
     
         4 . The audio receiving device according to  claim 3 , wherein
 the predefined time is 20 seconds or less.   
     
     
         5 . The audio receiving device according to  claim 3 , wherein
 the analyzing unit is configured to determine the correlation measurement time and/or the number of correlation measurements to be performed before deciding on the current correlation based on a target signal to noise ratio.   
     
     
         6 . The audio receiving device according to  claim 2 , wherein
 the analyzing unit is configured to estimate a correlation between the two signals based on parts of the signals in question.   
     
     
         7 . The audio receiving device according to  claim 2 , wherein
 the analyzing unit is configured to estimate a correlation between the two signals based on voice detection in the respective signals.   
     
     
         8 . The audio receiving device according to  claim 2 , wherein
 the analyzing unit is configured to determine an estimate of a correlation between the two signals in one or more particular sub-frequency ranges or bands of the total frequency range of the respective signals.   
     
     
         9 . The audio receiving device according to  claim 1 , wherein
 the audio receiving device is configured to generate an activity control signal indicative of whether the wireless receiver is receiving a signal on the currently selected channel.   
     
     
         10 . The audio receiving device according to  claim 9 , wherein
 the audio receiving device is configured to change to another channel selected among said predefined number of possible radio channels in case the activity control signal indicates that the currently selected channel is not active.   
     
     
         11 . The audio receiving device according to  claim 1 , wherein
 the audio receiving device is configured to enter into a specific mode of operation, and to perform said selecting, analyzing, and determining when the audio receiving device is in the specific mode of operation.   
     
     
         12 . The audio receiving device according to  claim 1 , further comprising:
 an indicator for indicating when a receiving channel has been identified.   
     
     
         13 . The audio receiving device according to  claim 12 , wherein
 the indicator is visually perceptible to a user.   
     
     
         14 . The audio receiving device according to  claim 1 , wherein
 the audio receiving device is adapted to be detachably attached to another device.   
     
     
         15 . The audio receiving device according to  claim 1 , further comprising:
 a voice detector for determining whether or not the electric input signal comprises a voice signal at a given point in time.   
     
     
         16 . The audio receiving device according to  claim 15 , wherein
 a correlation measurement is only initiated, if a voice is detected in the signal picked up by the microphone.   
     
     
         17 . The audio receiving device according to  claim 1 , wherein
 the audio receiving device is configured 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 a relevant transmission channel.   
     
     
         18 . The audio receiving device according to  claim 1 , wherein the audio receiving device comprises:
 a hearing aid,   a headset,   an ear phone,   an active ear protection device, or   a combination thereof.   
     
     
         19 . A hearing aid, comprising:
 the audio receiving device according to  claim 1 .   
     
     
         20 . A headset, comprising:
 the audio receiving device according to  claim 1 .