Methods and apparatus for outputting a haptic signal to a haptic transducer

1. A method for outputting a first haptic signal to a haptic transducer in a device, comprising:

receiving an audio signal for output through an audio output transducer;

executing a first process to determine, based on the audio signal and at least one criteria, a haptic signal for outputting to the haptic transducer in synchrony with the audio signal for output through the audio output transducer; and

simultaneous to execution of the first process, executing a second process to dynamically adjust the at least one criteria used by the first process based on a parameter for use in the first process, wherein the second process is separate to the first process, is slower than the first process and uses more processing power than the first process, wherein the parameter comprises one or more of the following: information relating to content of media playback for playback in conjunction with the audio signal, information relating to content of the audio signal, information relating to historical haptic events associated with the audio signal, and a battery charge status of the device.

2. The method of claim 1 further comprising:

responsive to the audio signal meeting a first criteria of the at least one criteria, determining that the audio signal comprises a haptic trigger, and

responsive to determining that the audio signal comprises the haptic trigger, outputting the haptic signal to the transducer.

3. The method of claim 2 wherein the first criteria comprises a threshold rate of change of the audio signal.

4. The method of claim 2 further comprising:

determining the haptic signal based on the haptic trigger and on a second criteria of the at least one criteria.

5. The method of claim 2 further comprising:

generating the haptic signal from the haptic trigger based on a third criteria of the at least one criteria.

6. The method of claim 5 wherein the third criteria comprises one or more of the following: a maximum amplitude, an allowed dynamic range and an allowed frequency range.

7. The method of claim 1 wherein the step of adjusting comprises adjusting the at least one criteria to reduce a repetition rate of haptic signal events derived from the audio signal responsive to the parameter indicating that a future repetition rate of haptic signal events should be reduced.

8. The method of claim 7 wherein the parameter indicates whether or not the audio signal comprises speech, and wherein the step of adjusting comprises:

adjusting the at least one criteria to reduce the repetition rate of haptic signal events responsive to the parameter indicating that the audio signal comprises speech.

9. The method of claim 7 wherein the parameter comprises a battery charge status of the device, and wherein the step of adjusting comprises:

adjusting the at least one criteria to reduce the repetition rate of haptic signal events responsive to the parameter indicating that the battery charge status is below a threshold level.

10. The method of claim 1 wherein the parameter comprises information relating to the content of media playback for playback in conjunction with the audio signal; and wherein the step of adjusting comprises adjusting the at least one criteria to select a haptic signal based on the content of the media playback.

11. The method of claim 10 wherein the media playback comprises video data.

12. The method of claim 1 wherein the parameter comprises information relating to historical haptic events associated with the audio signal; and wherein the step of adjusting comprises adjusting the at least one criteria to optimize expected future output of a repeated haptic event.

13. The method of claim 1 , wherein the step of executing the second process is of a higher latency than the step of executing the first process.

14. The method of claim 1 , wherein the step of executing the second process trains or adapts the first process, without affecting the latency of the step of executing the first process.

15. A processor for outputting a first haptic signal to a haptic transducer in a device, comprising:

an input configured to receive an audio signal for output through an audio output transducer;

a haptic signal determination block configured to execute a first process to determine, based on the audio signal and at least one criteria provided by a second process, a haptic signal for outputting to the haptic transducer in synchrony with the audio signal for output through the audio output transducer, wherein the processor is configured to, simultaneous to execution of the first process, execute a second process to dynamically adjust the at least one criteria used by the first process based on a parameter for use in the first process, wherein the second process is separate to the first process, is slower than the first process and uses more processing power than the first process, wherein the parameter comprises one or more of the following: information relating to content of media playback for playback in conjunction with the audio signal, information relating to content of the audio signal, information relating to historical haptic events associated with the audio signal, and a battery charge status of the device, wherein the step of executing the second process does not affect a latency of the step of executing the first process.

16. The processor of claim 15 wherein the processor is configured to adjust the at least one criteria to reduce a repetition rate of haptic signal events during the audio signal responsive to the parameter indicating that a future repetition rate of haptic signal events should be reduced.

17. The processor of claim 16 wherein the parameter indicates whether or not the audio signal comprises speech, and wherein the processor is configured to adjust the at least one criteria to reduce the repetition rate of haptic signal events responsive to the parameter indicating that the audio signal comprises speech.

18. The processor of claim 16 wherein the parameter comprises a battery charge status of the device, and processor is configured to adjust the at least one criteria to reduce the repetition rate of haptic signal events responsive to the parameter indicating that the battery charge status is below a threshold level.

19. The processor of claim 15 wherein the parameter comprises information relating to the content of media playback for playback in conjunction with the audio signal; and wherein the processor is configured to adjust the at least one criteria to select a haptic signal based on the content of the media playback.