tone down vs dampen

tone down and dampen both are verbs.

Word	Noun	Adjective	Verb	Adverb
tone down	No	No	Yes	No
dampen	No	No	Yes	No

As verbs, tone down and dampen are synonyms defined as:

Other synonyms of tone down include damp, dull, muffle, mute.

tone down (verb)	dampen (verb)
make less strong or intense; soften	lessen in force or effect
deaden (a sound or noise), especially by wrapping	make moist
	check; keep in check (a fire)
	make vague or obscure or make (an image) less visible
	reduce the amplitude (of oscillations or waves)
	suppress or constrain so as to lessen in intensity
	deaden (a sound or noise), especially by wrapping