I've been travelling recently and at multiple stations there have been speakers emitting a bleep every second. (For example Stansted Airports station).
Is there a reason for this?
Is the bleep louder every 10 seconds, even louder every minute, even louder every 10 minutes, even louder every hour, and loudest at 10:00:00, 20:00:00, and 00:00:00? If so, it might be the mechanism of the station clocks. Many of the older clocks with digital display make a clicking sound every second as one or more of the six figures changes.