I would like to modify this so the buzzer starts at 15% and goes up to 30% in volume.
amixer -D pulse sset Master 30% > /dev/null 2>&1
cvlc --play-and-exit /usr/share/sounds/My_Sounds/Alarm-sound-buzzer.mp3 > /dev/null 2>&1
echo 'TIME IS UP.'
gxmessage -fg blue -font 'sans 20' -timeout 2 ' TIME IS UP !!'