Siren/alarm on grid before race start

I cannot find a fragment/clip in which you can hear one of these sirens or alarms that always play before races start. It's a sort of horn/alarm that rings 5(?) times shortly after each other. I think you can mostly hear this sound when the grid is still forming up, with the mechanics, before the warm-up lap. Does it signify the start of the race in just a few minutes or something?
Submitted May 05, 2018 at 12:05PM by itswilliam https://www.reddit.com/r/motogp/comments/8h6v3y/sirenalarm_on_grid_before_race_start/?utm_source=ifttt