High Volume Alarm Event
The purpose of the High Volume Alarm event is to warn the user that the volume level of the detected audio is above the maximum acceptable level for performing meaningful audio analysis (i.e. approaching a level where the audio will likely become distorted). This event is only reported in Non-Referenced Mode.
A High Volume Alarm event is generated when the detected audio volume is continuously above the high volume threshold (see " High Volume Threshold Example") for 10 consecutive 0.5 sec measurement intervals (i.e. 5 sec total). The event will not be repeated again until the detected volume level drops below the high volume threshold. The High Volume Alarm event will then be reported again if the high volume condition returns for 10 more consecutive 0.5 sec measurement intervals.
Listed below are the high volume threshold levels. Note that the thresholds are different for music versus speech since the crest factor (difference between peak and average levels – see "Crest Factor") is different for those types of audio. Note that speech is typically transported in A2DP connections, and music is typically transported in SCO connections.
- Speech: greater than -6 dBFS
- Music: greater than -12 dBFS
The info reported with the High Volume Alarm event is listed below:
- Info1: Average (RMS) level at the start of the 5 sec interval
- Info2: The time at when the system began detecting high volume (i.e. 5 sec before the event was reported)
- Msg: Not used.
