CALM Act: Facts and How to Protect Yourself

September 27, 2011

The Following are FAQ’s relating to the practical effects of the recently passed CALM Act. 

The Commercial Advertisement Loudness Mitigation Act (H.R. 1084/S. 2847) (CALM Act) is legislation introduced by United States Senator Roger Wicker, a member of theUnited States Senate Committee on Commerce, Science and Transportation, on June 18, 2008.[1] It requires the Federal Communications Commission to regulate the audio of TV commercials from being broadcast at louder sound volumes than the TV program material they accompany.[2] The bill passed on September 29, 2010.[3] The bill requires the use of technology to ensure that commercials will be played at the same volume as the program. The U.S. Federal Communications Commission (FCC) will begin enforcing this bill within a year.[4]

The bill was the United States Senate companion to proposed legislation in the House of Representatives by Representative Anna Eshoo, a member of the Energy and Commerce Committee. The House bill has passed the Communications Subcommittee. Most of the bill consists of steps taken voluntarily by the broadcast industry and approved as “recommended practice” by the Advanced Television Systems Committee (ATSC) on November 4, 2009.[5] In fact, Rep. Anna Eshoo (D-Calif) told the Wall Street Journal that legislation to mitigate the volume of commercials on TV was among the most popular pieces of legislation she’s sponsored in her 18 years in Congress.

Prior to adjourning for the midterm recess, the United States Senate unanimously passed the bill on Thursday, September 30, 2010.[6] Before it was signed into law by the Presidentin December, minor differences between the two versions had to be worked out when Congress returned to Washington after the November 2 election.[7] The reconciled bill was signed into law by President Barack Obama on December 15, 2010 as Public Law 111-311.[8]

Frequently Asked Questions:

Q: Is there a technical basis for the CALM Act?

A: The CALM Act refers directly to ATSC Recommended Practice A/85 “Techniques for Establishing and Maintaining Audio Loudness for Digital Television”, available for download free of charge at:

Q: What does a station have to do to ensure compliance?

A: The CALM act compels the FCC to enforce rules that have been the law for over a decade, namely that average integrated loudness of the station audio match the dialnorm metadata parameter in their transmitted Dolby® Digital (AC-3) stream.

Q: Does this mean that the audio must equal the dialnorm value constantly every second? 

A: No. If dialnorm is set to -24, the audio should measure 24LKFS on average, integrated over time. The precise time has not been established by the ATSC yet, but a useful range would be 10- 30 second integration. Some instantaneous variance is OK and expected – this simply means your audio has dynamics and this is a good thing. The key is that it should be correct on average. Q: Does the dialnorm value have to be -24? A: No. The dialnorm value can be any number between -31 (indicating very quiet audio) and -1 indicating very loud audio. The only rule is that dialnorm actually matches the measured loudness of the audio – or vice versa.

Q: How do I measure loudness?

A: A growing number of commercially available meters that support the ITU-R BS.1770 standard can do this. The DK Technologies PT0740 and PT0760 meters can display dialnorm provided they are fitted with their Dolby® Digital (AC-3) Decoder modules.

 Q: What if my station audio does not match the dialnorm value?

A: If it measures consistently at a given loudness value, simply re-adjust the dialnorm value to that number, or apply static gain or attenuation to the audio so it matches the dialnorm value.

Q: What if my station audio is sometimes too loud and sometimes too soft?

A: You may need to measure and fix each segment of audio separately. This may involve purchasing an ITU compliant meter and training staff to ingest material more consistently.

Q: Does this apply to my subchannels as well?

A: Yes, all transmitted channels must be compliant.