Computing device utilizing a resting surface as a speaker

1. A portable computer, comprising:

a speaker;

a transducer configured to utilize a surface in contact with the portable computer to generate an audible sound;

a sensor configured to generate a sensor signal representing a pressure associated with the surface;

a detector configured to determine at least one of a hardness value or a density value corresponding to the pressure; and

a controller configured to control the transducer for audible output based on the at least one of the hardness value or the density value and a threshold value.

2. The portable computer of claim 1 , wherein the sensor is a pressure sensor.

3. The portable computer of claim 1 , wherein the sensor is a displacement sensor.

4. The portable computer of claim 1 ,

wherein the at least one of the hardness value or the density value is looked-up in a table based on the pressure.

5. The portable computer of claim 1 , wherein

the speaker includes a diaphragm configured to generate air motion resulting in audible sound,

the transducer is configured to generate vibrations on the surface such that the surface generates air motion resulting in audible sound without the use of a diaphragm.

6. The portable computer of claim 1 , wherein the hardness value is a relative hardness value.

7. The portable computer of claim 1 , wherein the density value is a relative density value.

8. The portable computer of claim 1 , wherein the sensor signal is a first sensor signal, the threshold value is a first threshold value,

the portable computer, further comprising:

a gyroscope configured to generate a second sensor signal indicates an orientation of the surface relative to the portable computer, wherein

the detector is configured to generate a level characteristic based on whether or not the portable computer is level in relation to the surface based on the orientation, and

the controller selects the transducer for audible output based on the level characteristic and a second threshold value.

9. The portable computer of claim 1 , wherein the sensor signal is a first sensor signal, the threshold value is a first threshold value,

the portable computer, further comprising:

an accelerometer configured to generate a second sensor signal indicates a movement of the portable computer, wherein

the detector is configured to generate a movement characteristic based on whether or not the portable computer is moving relative to the surface based on the movement of the portable computer, and

the controller selects the transducer for audible output based on the movement characteristic and a second threshold value.

10. The portable computer of claim 1 , wherein

the speaker includes a diaphragm configured to generate air motion resulting in audible sound,

the transducer is configured to generate vibrations on the surface such that the surface generates air motion resulting in audible sound without the use of a diaphragm.

11. The portable computer of claim 1 , wherein the threshold value is a first threshold value,

the portable computer further comprising:

a microphone configured to detect a tone representing an audible characteristic; wherein

the controller is configured to generate an acoustic tone utilizing the transducer, and

the detector determines if the surface is capable of generating audible sounds based on the detected tone, the generated acoustic tone and a second threshold value.

12. The portable computer of claim 1 , further comprising

at least one pad located on an exterior of the portable computer and configured to be in direct contact with the surface, wherein

the transducer is configured to generate vibrations on the surface using the at least one pad such that the surface generates air motion resulting in audible sound.

13. The portable computer of claim 1 , further comprising:

a first filter configured to pass signals associated with a first frequency range;

a second filter configured to pass signals associated with a second frequency range, the first frequency range being different from the second frequency range; and

a switch configured to selectively select the output of the first filter as input to the speaker and the output of the second filter as input to the transducer based on a selection signal from the controller.

14. The portable computer of claim 1 , wherein the controller is further configured to:

determine if multi-channel audio is selected based on a user selection;

select both the speaker and the transducer if multi-channel audio is selected and if the surface is capable of generating audible sounds, wherein

the speaker outputs audible sounds associated with a first frequency range;

the transducer outputs vibrations associated with a second frequency range, the first frequency range being different from the second frequency range.

15. A method for generating audible output in a computer device, the method comprising:

determining, by a detector of the computer device based on a received sensor signal, at least one of a hardness value or a density value corresponding to at least one characteristic associated with a surface which the computer device is in contact with, the at least one characteristic including a pressure; and

controlling, by a controller of the computer device, a transducer configured to generate vibrations on the surface such that the surface generates air motion resulting in audible sound for use as audible output of the computer device based on the at least one of the hardness value or the density value corresponding to the at least one characteristic of the surface and a threshold value.

16. The method of claim 15 , wherein the transducer is selected if the surface is capable of generating audible sounds based on the characteristic.

17. The method of claim 15 , wherein a speaker is selected if the surface is not capable of generating audible sounds based on the characteristic.

18. The method of claim 15 , further comprising:

determining if multi-channel audio is selected based on a user selection;

selecting both a speaker and the transducer if multi-channel audio is selected and if the surface is capable of generating audible sounds based on the characteristic, wherein

the speaker outputs audible sounds associated with a first frequency range;

the transducer outputs vibrations associated with a second frequency range, the first frequency range being different from the second frequency range.