Motion Based Compensation of Downlinked Audio

1 . A method of compensating for movement of a loudspeaker relative to a user's head, wherein the loudspeaker is present in a device, the method comprising:

producing, by the device, an electrical signal representative of audio;

determining, by the device, a distance between the device and the user's head;

setting, by the device, a gain of the electrical signal in accordance with the distance;

receiving a volume set activation request;

determining, by the device, a change in distance between the device and the user's head relative to the distance determined previously;

adjusting the gain of the electrical signal in inverse proportion to the change in distance between the device and the user's head; and

outputting audio, via the loudspeaker of the device, corresponding to the electrical signal with the gain as adjusted.

2 . The method of claim 1 wherein the adjusting comprises:

increasing the gain of the electrical signal when the distance between the device and the user's head decreases; and

decreasing the gain of the electrical signal when the distance between the device and the user's head increases.

3 . The method of claim 1 , further comprising:

determining, by the device, a velocity of the device relative to the user's head;

processing the electrical signal representative of audio to compensate for a Doppler effect caused by the velocity.

4 . The method of claim 1 , wherein the device comprises a front of the device, and wherein the determining, by the device, the distance between the device and the user's head comprises:

determining, by the device, a distance between the front of the device and an object situated before the front of the device.

5 . The method of claim 4 , wherein the determining, by the device, the distance between the front of the device and the object situated before the front of the device comprises:

sending an infrared signal or an ultrasonic signal from a front face of the device to the object.

6 . The method of claim 1 , wherein the determining, by the device, the distance between the device and the user's head comprises:

automatically detecting a human face.

7 . The method of claim 1 , further comprising:

periodically repeating the steps of determining and setting.

8 . The method of claim 1 , further comprising:

in response to detecting an acceleration of the device exceeding a predetermined threshold, repeating the steps of determining and setting.

9 . An apparatus for compensating for movement of a loudspeaker relative to a user's head, wherein the loudspeaker is present in a device, the apparatus comprising:

a source of an electrical signal representative of audio;

a sensor system configured to determine a distance between the device and the user's head;

a user interface configured to receive volume set activation request;

logic, coupled to the user interface and the sensor system, configured to set a gain of the electrical signal in accordance with the distance and configured to adjust the gain of the microphone inversely proportional to a change in distance between the device and the user's head when the volume set activation request is received;

an amplifier, coupled to the source and the logic; and

a loudspeaker, operably coupled to the amplifier, to receive the electrical signal representative of the audio with the gain as adjusted by the logic.

10 . The apparatus of claim 9 wherein the logic increases the gain of the electrical signal when the distance between the device and the user's head decreases and decreases the gain of the electrical signal when the distance between the device and the user's head increases.

11 . The apparatus of claim 9 , wherein the device comprises a cellular telephone.

12 . The apparatus of claim 9 , further comprising:

means for determining, by the device, a velocity of the loudspeaker relative to the user's head;

logic configured to process the electrical signal representative of audio to compensate for a Doppler effect caused by the velocity.

13 . The apparatus of claim 9 , wherein the sensor system comprises at least one of: an infrared sensor, an ultrasonic sensor, or a camera.

14 . The apparatus of claim 9 , wherein the sensor system comprises an accelerometer.

15 . The apparatus of claim 9 , wherein the apparatus is a mobile telephone.

16 . The apparatus of claim 9 , further comprising:

logic configured to revise a determination of the distance between the device and the user's head whereby a revised distance is determined, and

a timer configured to periodically trigger a redetermination of the gain of the electrical signal in accordance with the revised distance.

17 . The apparatus of claim 9 , wherein the sensor system comprises an accelerometer, and wherein the amplifier is further configured to automatically redetermine the gain of the electrical signal, in accordance with a revised distance, in response to the accelerometer detecting an acceleration of the apparatus exceeding an predetermined threshold.