FAQ's About the CALM Act


What is the CALM Act?

Signed into law on December 15, 2010 by U.S. President Barack Obama, Bill HR 6209, or the Commercial Advertisement Loudness Mitigation (CALM) Act, was originally introduced by Congresswoman Ana Eshoo of California. The new U.S. law makes it illegal for commercials to be overly loud compared to the rest of the programming on a given channel. On December 13, 2011, the FCC moved to implement the Act and established rules for over-the-air television broadcasters, cable operators, and satellite television to demonstrate compliance.

When will the rules become effective?

The rules will become effective on December 13, 2012, one year after the date of their adoption, giving broadcast television stations, cable providers, and satellite providers one year to be in full compliance. A one-year waiver (with an additional one-year renewal) may be granted by the FCC if procuring equipment can be proven to be a financial hardship.

How will the rules be enforced?

Although the responsibility for compliance has been placed upon broadcasters and MVPDs (multi-channel video program distributors), enforcement of the rules will be based primarily upon complaints from viewers.

Is there a technical basis for this?

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: www.atsc.org/cms/standards/a_85-2009.pdf.

What does my station have to do to ensure compliance?

Essentially, 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.

Does this mean the audio must equal the dialnorm level every second?

No. If dialnorm is set to -24, the audio for each segment should measure 24LKFS on average, integrated over time. 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.

Does the dialnorm have to be -24?

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.

How do I measure loudness?

A growing number of commercially available meters that support the ITU-R BS.1770-1 standard can do this. The Linear Acoustic L.A.M.B.D.A. II displays both the dialnorm value and the LKFS measurement, while the LQ-1000 will measure and provide a histogram of the results. The Linear Acoustic AERO.air Transmission Loudness Managers have loudness correction and confidence metering all in one.

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

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.

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

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. It may also involve using file-based tools such as the AERO.file to adjust content that is already present on servers or is delivered via FTP.

Does this apply to my subchannels as well?

Yes, all transmitted channels must be compliant.

What if I do not have the staff or something slips through during live programming?

It is also probably a good idea to consider installing a transmission processor such as a Linear Acoustic AERO.air or AERO.one to catch any content that is not corrected in time for transmission. The best method is to get content correct before transmission to minimize the degree of processing required for compliance. Remember, the more severe the mismatch, the more processing is required to fix it.

I recently received a letter advising me to bypass all processing, what should I do?

If you trust the network feed to be correct 100% of the time, then it might be worth the risk. If you suspect that the network audio is generally consistent but it might be better to be safe, a prudent approach would be to leave the processor in line and pick a very light preset. If you are not sure and do not want to risk the wrath of a bill that passed congressional voting unanimously or worse that you might drive away viewers and affect ratings due to inconsistent loudness and varying spectral balance- we recommend making sure that processing is in line and set to the minimum required to keep measured audio matching to your dialnorm setting. Remember, ATSC A/85 supports processing as a valid method of handling loudness.

Is there a way to process local and network audio differently?

Any AERO.air 5.1 or AEROMAX 5.1 has always supported a 5.1+2 program configuration with the ability to have local and network with their own processing cores. The new AERO.one 5.1+2 mode also supports this mode of operation. Please contact your sales engineer or the factory for setup assistance or upgrade details.

Where can I learn more about compliance and DTV audio in general?

Our website has a considerable amount of information in the form of white papers and product brochures. Also, please contact the sales engineer in your area as they are very knowledgeable and have a great deal of experience successfully helping hundreds of stations cost effectively get compliant and sound good.



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