Absolutely. Just make sure you use plenum rated speaker wires if you
run them inside the walls.
Unless the walls are being used for heating/cooling air passage, this
would not be correct.
Plenum-rated cable gets its name from an HVAC term—plenum spaces.

I'm probably just using the wrong terminology again. It has been 12 years
since we built our house, so some of the details get a little foggy these
days.

When we built our house in 2003 we were required by code to use CL2 or CL3
rated speaker wire. Both types are widely available and relatively
inexpensive.

The important tip was the original poster shouldn't just run bare two
conductor speaker wires inside the walls.

Anthony Watson
www.mountainsoftware.com
www.watsondiy.com