int sm_play_tone_abort(tSMChannelId channel)
This call enables an application to abort a previously initiated tone generation job on the specified channel (as long as the wait_for_completion flag was not used in the previous call to sm_play_tone()). The channel will revert to outputting silence.
0 if call completed successfully, otherwise a standard error such as:
This function is part of the Prosody speech processing API.