Cheer.
The synonym for group that rhymes with loud is crowd.
If you mean "Do 'the loud' and 'aloud' rhyme?", yes, they do.
No. Please see the related questions below for "What rhymes with around?" and "What rhymes with loud?"
loud crowd
a row
proud fang
row
Boomy
a rainy cloud
Something that is not loud enough to hear is referred to as "inaudible" or "too quiet."
loud crowd
loud