songbird wrote:

if it is for a garden why not be more creative with
the space and have it as a green wall for growing things?

while i don't find rock walls ugly i don't think i'd
much like to look at a barren fenced pile of rocks for
years at a time.

There are many plants that love a rock wall. However the OP wants to
supress sound and stone actually deflects and amplifies sound, a
wooden fence will absorb and supress sound.