Level 1 (1 loadout point)- The listen mode meter regenerates 10% faster and you can listen for 10% longer.
Level 2 (2 loadout points)- The listen mode meter regenerates 20% faster, and stay in listen mode 20% longer.
Level 3 (3 loadout points)- Enter listen mode more quickly, you do not slow down while crouch-walking in listen mode, the meter regenerates 30% faster, and stay in listen mode 30% longer.
Levels 1 and 2 of Sharp Ears grants better options for hearing awareness, making it more difficult for enemies to flank users. Level 3 Sharp Ears allows users to enter listen mode quickly and without sacrificing speed while still being aware.
Listen Mode stacks well with Covert Training 2 or higher, which allows users to crouch walk without appearing on listen mode. Conversely, Covert Training 2 is a great counter against users of Sharp Ears.
The survival skill Lone Wolf grants Sharp Ears in addition to other useful survival skills when the user is far away from his or her teammates.