With Rep. Anna Eshoo’s bill to turn down TV ads in the news (Commercial Advertisement Loudness Mitigation, or CALM, Act), here again is my explanation of why ads sound so loud when broadcasters claim they hit the same levels as the rest of the programming:
People have complained about loud TV commercials for years. The response has often been that technically, commercials are no louder than anything else on the air. The FCC even supports this argument is a section of its web site (which they say is being updated – and, I hope, corrected):
Loud Commercials. In surveys and technical studies of broadcast advertising, we have found that loudness is a judgment that varies with each listener and is influenced by many factors (such as an announcement’s content and style). We have also found no evidence that stations deliberately raise audio and modulation levels to emphasize commercial messages.
As whoever wrote this must know, the claim that commercials are not louder is only true in an artificially narrow sense. The peak levels of commercials are no higher than the peak levels of program content. But the average level is way, way higher, and that’s the level your ears care about. If someone sets off a camera flash every now and then it’s one thing; if they aim a steady spot light into your eyes it’s another, even if the peak brightness is no higher.
Quoted at msnbc.com:
http://www.msnbc.msn.com/id/17229281/
In the Reader’s Digest:
http://www.rd.com/living-healthy/why-are-tv-commercials-so-loud/article96931.html
And the more detailed original post at O’Reilly Digital Media:
http://blogs.oreilly.com/digitalmedia/2007/01/bless-you-dolby-technology-lim.html