Locate the control panel for your ADT alarm system. This is usually located near your front door or other entry point into your home. Remove the control panel cover and access the interior of the control panel. Find the volume setting dial and turn it clockwise to increase the sound level of your alarm system.

How do I lower the volume on my ADT security system keypad (Lynx)? Press #, then 2, and then push 6 (the down arrow). To increase the volume, push #2 and then 3 (the up arrow). You can continue to push 3 or 6 to keep going up or down.