Dynamic speaker management with echo cancellation

Abstract

An echo cancellation system includes a dynamic speaker management (DSM) module, a current / voltage sense amplifier, a sound pressure level (SPL) model module, and an echo canceller. The exemplary DSM module can receive a remote signal and be used to generate a modified remote signal and multiple parametric outputs. An exemplary current / voltage sense amplifier is coupled to the modified remote signal and generates an amplifier output, a voltage (V) parametric output, and a current (I) parametric output. An exemplary sound pressure level (SPL) model module is coupled to the various parameter outputs of the DSM module and used to generate a predicted SPL. The exemplary echo canceller module is responsive to the predicted SPL and near-end signal and is used to generate an echo canceled output signal.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of US Provisional Patent Applications USSN 61 / 721010, 61 / 721015, and 61 / 721021, all filed October 31, 2012, the entire contents of which are hereby incorporated by reference. Background technique [0003] The current trend is to provide louder sound pressure levels ("SPL") at the output of micro-speakers in various devices such as feature phones, smartphones, and tablets. The speakers here are alternatively also referred to as "amplifiers". As known to those skilled in the art, SPL is a measure of the change in sound pressure in front of the speaker due to speaker operation. [0004] A problem that arises when increasing the SPL level in a speakerphone is that it usually causes the speaker to operate in a non-linear region. When a device is operating in speakerphone mode, it becomes difficult to effectively cancel echoes caused by direct or reflected acoustic paths between the speake...

AI Technical Summary

Problems solved by technology

[0006] The problem with the first example operation of the block diagram of Figure 1 is that the reference R1 does not have an accurate representation or "model" of the true SPL variation at the loudspeaker, resulting in poor echo cancellation

The second example operation results in a better representation or better SPL "model" of the loudspeaker, but only at the expense of attaching the sensor S to the loudspeaker carton, which affects the SPL characteristics of the loudspeaker, and increases system cost

However, since the reference (e.g. RI) fed to a conventional echo canceller does not carry any information about the nonlinearity introduced by the loudspeaker, a prior art echo canceller that does not use the sensor S will not be able to remove the nonlinear component , resulting in more residual echo in the echo-cancelled speech

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