Patent ID: 7072476

Claim:
An audio device, comprising: an earpiece having a transducer that converts an input audio signal from a user into a transmit signal and also converts a receive sianal received from an external device into an audio output sianal intended for listening to by the user, the receive signal including transmit signal components; a full duplex mode circuit coupled to the transducer including: a first amplifier having a first input coupled to a first terminal of the transducer and a second input receiving a receive signal with reduced transmit signal components, wherein the first amplifier outputs a combined output signal that includes the transmit signal and the receive signal with the reduced transmit sianal components; and a second amplifier having a first input coupled to ground and a second input coupled to the same receive signal with the reduced transmit signal components received by the first amplifier, wherein the second amplifier outputs the receive signal with the reduced transmit signal components; and a digitall signal processing system that isolates the transmit signal from the receive signal, including; a first input receiving the combined output signal from the first amplifier; a second input receiving the receive signal from the external device having the transmit signal comnonents; an output outputting the receive signal with the reduced transmit signal components to the first and second amplifiers: and a third input receiving the receive signal with the reduced transmit signal components back from the second amplifier.