wekk i have a uk dave silencer fitted to my air arms tx200hc , its .177 . i have no idea what the db noise is .....so i tested it by having a mate stand down by a tin beer can at 40 yards ..... ( he was about 15 yards off to the left laying down on the ground) the can was about 5 foot up on a pole. Without the silencer, he heard the crack when i fired it .. then the pellet hit the can.... when i put the silencer on, he heard nothing whatsoever and the first he even knew i had fired , was when the pellet hit the can.