attenuateformal
Notice the attenuating force of 'a bit' in "That's a bit too much."
The material is highly attenuating, meaning it absorbs and lessens sound going through it.
Exhaustion had an attenuating effect on her feelings.

SMART Vocabulary: related words and phrases

Becoming and making less strong
abate
abatement
adulterant
adulterate
adulterated
dull
ease
emasculation
enervate
enervating
enervatingly
fade
hedge
melt
relieve
totter
tottering
turn to jellyidiom
undimmed
unsubdued

You can also find related words, phrases, and synonyms in the topics:

Becoming and making smaller or less