Once the phone call has started to record, the 3CX Recording Beep waits for the specified initial delay (in seconds) and then plays an audible beep to alert both the call participants about the ongoing call recording. This will be the last beep for the call if you have opted to play the beep only once. However, if you have opted to play the beep throughout the ongoing call, then the 3CX Recording Beep continues to play the beep according to the configured frequency (in seconds) until the call lasts.