Sound fix in CS

in aztec, train etc. there comes this annoying background sounds.
is there any cvar to remove it?
like cl_weather 0, to remove the weather in aztec.

stopsound?

it is an overall sound which the mapper placed in.
if you type stopsound every new round should fix it.
another tipp would be try to search the soundfile and replace it with a dummyfile.