Proximity sensing for user detection and automatic volume regulation with sensor interruption override

A mobile device comprising:

• at least one speaker;
• an audio subsystem for providing an amplified audio signal to the at least one speaker for output by the at least one speaker, the audio subsystem comprising:
• an audio source for generating an audio signal;
• a proximity sensor comprising a detection circuit configured to generate a sensor output signal representing a distance to a user of the mobile device, and a failsafe generator coupled to the detection circuit and configured to generate a sensor status signal indicating an operational status of the proximity sensor;
• and
• a power amplification module configured to process the audio signal received from the audio source into the amplified audio signal for output by the at least one speaker, the power amplification module comprising a gain controller responsive to the sensor output signal and the sensor status signal to determine and apply a gain factor to the audio signal based on the distance to the user of the mobile device and the operational status of the proximity sensor.

A method for controlling volume output in at least one speaker of a mobile device, the method comprising:

• a proximity sensor detecting a distance to a user of the mobile device;
• monitoring an operational status of the proximity sensor;
• providing an audio signal from an audio source;
• processing the audio signal into an amplified audio signal by determining and applying a gain factor to the audio signal based on the distance to the user of the mobile device and the operational status of the proximity sensor;
• and
• providing the amplified audio signal to the at least one speaker for output by the at least one speaker.