Two beeps are emitted during the countdown every minute until the last minute. Then:
• 50 seconds before the end of the countdown, one beep emitted.
• 40 seconds before the end of the countdown, one beep emitted.
• 30 seconds before the end of the countdown, two beeps emitted.
• 20 seconds before the end of the countdown, two beeps emitted.
• 10 seconds before the end of the countdown, one beep emitted every second
to indicate the end of the countdown.
At the end of the countdown, one long beep emitted for one second to tell the user
that the countdown has reached zero. Timing starts.
30