Patent ID: 8160263

Claim:
A mobile communication device comprising a digital signal processor (DSP), a microphone input node, a speaker output node, an analog front-end, and an antenna, the mobile communication device adapted to operate in a call mode and a non-call mode, wherein: the microphone input node is adapted to receive a first audio signal corresponding to sound captured by a microphone connected to the microphone input node and located near a user of the mobile communication device; the DSP comprises a noise characterizer, a noise suppressor, and a received-audio processor; if the mobile communication device is operating in the call mode, then: (a) the DSP (i) derives a background noise signal from the first audio signal, wherein the background noise signal substantially characterizes background noise near the user, (ii) generates a second audio signal substantially equivalent to the sum of the first audio signal and an inverse of the background noise signal, and (iii) provides the second audio signal to the analog front-end; (b) the analog front-end receives the second audio signal and generates a corresponding first radio-frequency signal for transmission by the antenna to a wireless network; (c) the antenna receives from the wireless network a second radio-frequency signal for transmission to the analog front-end, which generates a corresponding received-audio signal; (d) the DSP provides to a speaker via the speaker output node a speaker output signal based on the received-audio signal; (e) the noise characterizer derives the background noise signal from the first audio signal; (f) the noise suppressor generates the second audio signal using the background noise signal and the first audio signal; and (g) the received-audio processor processes the received-audio signal from the analog front-end and generates the speaker output signal based on the received-audio signal, for provision to the speaker via the speaker output node; and if the mobile communication device is operating in the non-call mode, then: (a) the DSP (i) generates a speaker output signal based on at least the first audio signal, and (ii) provides the speaker output signal to a speaker via the speaker output node; and (b) the noise suppressor generates the speaker output signal based on at least the first audio signal, for provision to the speaker via the speaker output node.