Audio Warnings

I own a Chevrolet Impala 2001 LS. Two weeks ago I started having a problem where when the key would be in the ignition and doors opened with engine off, the chimes to remind the driver that the key is in the iginition was distorted and going in and out. When I started the car and turned on the radio there was no audio. I turned on the Onstar and didnt get any audio prompts, and when I turned off my Traction Control I didnt get the four chimes that alerts the driver that the traction control is off. Anything audio just goes dead or distorted. I took the car to the Chevy dealer where they replaced the BCM. All worked fine with all audio warnings, radio audio, onstar etc, for two weeks until yesterday when the issue started again where it would distort, and go out completely then come back fine for a while then go back to being distorted. Could the problem be the igintion switch along with the BCM? After having the original BCM replaced, could it be where two different BCM's experience the same issues? Ive tried to read up on maybe someone else experiencing this same issue with no success. Can anyone here help with some advice and answers?