Commercial Advertisement Loudness Mitigation Act or the CALM Act - Directs the Federal Communications Commission (FCC) to prescribe a regulation that is limited to incorporating by reference, and making mandatory, the Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television approved by the Advanced Television Systems Committee, so far as the recommended practice concerns the transmission of commercial advertisements by a television broadcast station, cable operator, or other multichannel video programming distributor. Allows the FCC to waive the regulation if obtaining the equipment to comply would result in financial hardship.