CALM stands for Commercial Advertisement Loudness Mitigation. The act is designed to prevent TV commercials from blaring at louder volumes than the program content they accompany. The rules govern broadcasters as well as cable and satellite operators.
The rules are meant to protect viewers from excessively loud commercials.
The Federal Communications Commission adopted the rules a year ago, but gave the industry a one-year grace period to adopt them.
Suspected violations can be reported by the public to the FCC on its website.