You may choose to Trigger the camera when loud-enough noises are detected. The camera's trigger "break time" is used to end recording regardless of whether or not you have the video motion sensor enabled. You may adjust the sensitivity of the audio trigger (the loudness of the audio signal which will cause recording to begin). When the slider is toward the left, only very loud sounds will trigger recording. When the slider is toward the right, small sounds will also trigger recording. Maximum sensitivity is achieved when the microphone gain is high (or at max) and the trigger sensitivity is high (or at max). Beneath the sensitivity slider is an audio power meter, which will show the current strength of the audio signal. When the signal is sufficient to trigger recording, the meter will show in red. This meter may only be available once the audio source has been initialized (that is, you Ok the camera property window, and then return to this properties page).
By default, a 1 second average intensity is used for the audio trigger. With this option enabled, only longer/sustained noises will result in a trigger. With this option disabled, short noises such as a single hand-clap may be capable of triggering the camera.