Module C - Slide 10


The automatic volume adjustment makes the sounds respond to ambient sound, so a louder signal is produced when traffic is louder and there's  a quieter signal when traffic is quieter. The volume is supposed to be no more than 2 to 5 dB above ambient sounds. Experience indicates that most APS are installed with volume too loud, rather than too quiet. Often signals are pre-set for the volume range and may need adjustment when installed.