One of our local TV stations has an "Ask the General Manager" segment periodically on their morning show, and last week he addressed a question on this very issue. He explained that there's no FCC regulation on audio levels. The audio levels of commercials are set when they're recorded, so they can often be much louder than other broadcast content.
Most modern TVs have the ability to set the audio level to prevent the viewer from getting blasted when a show goes to commercial.
It is annoying, but I don't feel that it's something in which the the Federal gov't needs to become involved. It's just another perversion of the Constitution's Interstate Commerce Clause that creates more Fed gov't intrusion into the private sector.:angry: