This slide shows the sound level scale, measured in decibels, ranging from the threshold of hearing at 0 decibels to the threshold of pain at 130 decibels. Different common sounds are also shown to give an idea of what these sound levels mean in every-day life. An audible alarm’s sound level should be at least 10 decibels above the ambient background noise to be easily heard. If the ambient background noise cannot be easily measured, then the user must rely on the experience of the audible alarm supplier and their own experience when specifying the alarm’s sound level.