Patent ID: 8204210

Claim:
An apparatus for non-linear acoustic echo cancellation due to loudspeaker nonlinearities in a device having or used with an acoustic coil and including a microphone, the apparatus comprising: a terminal configured and arranged to receive an electric signal representing for a coil at least one of a coil voltage and a current signal and estimates of a coil resistance and a coil inductance; a signal processing logic circuit configured and arranged to: determine a back EMF (BEMF) from the electrical signal integrate the BEMF with respect to time; estimate at least one of a cone position and a cone velocity based on the integrated BEMF; determine an estimate of an acoustical impulse response from the estimated at least one of the cone position and the cone velocity to a microphone pressure; determine an estimate of an echo value based on an estimated inverse of a force factor function primitive and the estimated acoustical impulse response; and a second terminal configured and arranged to output the estimated echo value, the estimate providing a signal for echo cancellation in the device.