An example here:
"Il est fort dommage pour l'enregistrement de cette sonate
que la prise de son desserve le piano, qui est légèrement
nimbé d'un voile sonore."
My attempt at a translation:
It is a great pity for the recording of that sonate that
the sound take disadvantages the piano that is slightly
swathed in a sound veil.
I understand it as a background sound that veils? another
one.
You might want to try the newsgroup sci.lang.translation
for that sort of questions there are some knowledgeable
people hanging there and it needs a bit of participation!