Abstract: A mobile communications device contains at least two microphones. One microphone is designated by a selector to provide a voice dominant signal and another microphone is designated to provide a noise or echo dominant signal, for a call or a recording. The selector communicates the designations to a switch that routes the selected microphone signals to the inputs of a processor for voice signal enhancement. The selected voice dominant signal is then enhanced by suppressing ambient noise or canceling echo therein, based on the selected noise or echo dominant signal. The designation of microphones may change at any instant during the call or recording depending on various factors, e.g. based on the quality of the microphone signals. Other embodiments are also described.

Abstract: An electronic device may operate in standby and active modes. A headset may be coupled to the electronic device. The electronic device may have audio codec circuitry. The audio codec circuitry may use general purpose input-output circuitry in handling button and headset activity during active mode. Processing circuitry may be used to reconfigure the audio codec in real time. When the electronic device is in the standby mode and activity is detected, the codec may be configured to provide an interrupt signal to a power management unit that wakes the device. When the electronic device is in active mode and no user inputs are received within a given period of time, the central processor in the electronic device may place the device in standby mode.