dampen

verb

1.
suppress or constrain so as to lessen in intensity
extinct stifle
2.
3.
deaden (a sound or noise), especially by wrapping
mum damp dull muffle mute tone down
4.
reduce the amplitude (of oscillations or waves)
5.
make vague or obscure or make (an image) less visible
damp deaden
6.
check; keep in check (a fire)
7.