System and method for communicating data during an audio conference

A method for a local communication device to communicate data to a remote communication device during an audio conference, the local communication device performing steps comprising:

• receiving a signal, the signal comprising an audio signal and a modulated carrier signal, wherein the audio signal is filtered to create a notch in the audio signal frequency spectrum at the frequency of the carrier signal, the amplitude of the modulated carrier signal is adjusted proportionally to the instantaneous amplitude of the audio signal within a range of no more than about twice the width of the notch from the frequency of the modulated carrier signal and the modulated carrier signal is added to the filtered audio signal and is substantially imperceptible from a far end conference device;
• and,
• the remote communication device performing steps comprising:
• separating the signal into an audio signal and a modulated carrier signal;
• demodulating the modulated carrier signal to extract digital data;
• and
• reproducing the audio signal.

A conference device for communicating data to a far end conference device during an audio conference, comprising:

• a microphone to generate an audio signal;
• a digital interface operable to receive digital data;
• a network interface to connect to the far end conference device;
• and
• a processor module coupled to the microphone, the digital interface and the network interface;
• wherein the processor module is operable to,
• receive the audio signal from the microphone;
• receive digital data through the digital interface;
• modulate the digital data onto a carrier signal;
• adjust the amplitude of the modulated carrier signal proportionally to the instantaneous amplitude of the audio signal within a range of no more than about twice the width of the notch from the frequency of the modulated carrier signal;
• filter the audio signal to create a notch in the audio signal frequency spectrum at the frequency of the carrier signal;
• combine the audio signal and the adjusted, modulated carrier signal by adding the modulated carrier signal to the filtered audio signal;
• and
• transmit the combined signal to the far end conference device.

A conference system for communicating data from between conference devices during an audio conference, comprising:

• a near end conference device, includes:
• a microphone to generate an audio signal;
• a digital interface operable to send digital data;
• a network interface;
• and
• a processor module coupled to the microphone, the digital interface and the network interface;
• and
• a far end conference device coupled to the near end conference device, includes:
• a loudspeaker to reproduce an audio signal;
• a digital interface operable to send digital data;
• a network interface to connect to the far end conference device to receive a far end signal;
• and
• a processor module coupled to the loudspeaker, the digital interface and the network interface,
• wherein the processor module in the near end conference device is operable to,
• receive the audio signal from the microphone;
• receive digital data through the digital interface in the near end conference device;
• modulate the digital data onto a carrier signal;
• adjust the amplitude of the modulated carrier signal proportionally to the instantaneous amplitude of the audio signal within a range of no more than about twice the width of the notch from the frequency of the modulated carrier signal;
• combine the carrier signal with the audio signal, wherein the audio signal is filtered to create a notch in the audio signal frequency spectrum at the frequency of the carrier signal and the modulated carrier signal is added to the audio signal such that the modulated carrier signal frequency is located at the notch such that the modulated carrier signal -is substantially imperceptible;
• and
• transmit the combined signal to the far end conference device;
• wherein the processor module in the far end conference device is operable to receive the combined signal from the network interface in the far end conference device;
• separate the audio signal and the modulated carrier signal from the combined signal;
• demodulate the carrier signal to extract digital data;
• send the digital data through the digital interface in the far end conference device;
• and
• send the audio signal to the loudspeaker for reproduction.