TV viewers finally should get some relief from a major annoyance: excessively loud commercials.
On Thursday, the Commercial Advertisement Loudness Mitigation Act, which limits the volume of TV commercials, goes into effect. The federal law, known as CALM, requires broadcasters to ensure that TV commercials maintain the same volume as the entertainment programming in which the ads are contained.
Prompted by an outcry from irritated consumers, Congress more than a year ago passed the law, sponsored by Rep. Anna G. Eshoo (D-Menlo Park). It will be enforced by the Federal Communications Commission.
Viewers can report super-loud commercials to the FCC on the agency's website or by calling 1-888-TELL-FCC (1-888-225-5322).
It would seem like an easy enough fix for broadcasters, but solving the volume problem required advances in technology -- and equipment upgrades for TV stations and cable and satellite TV operators that are responsible for modulating the volume.
Normal listening levels are about 70 decibels for a television show, but levels can vary. Sound metering equipment long used by broadcasters was not sensitive enough to discern fluctuations in volume.
"The old type of meter measured volts. They were just looking for technical indications of loudness, and those indications did not always relate to human perception," Thomas Lund, a development manager of Denmark's TC Electronic, said in a telephone interview.
"Levels and loudness are not always the same," he explained. For example, high levels of sound for a sustained duration comes across to the ear as louder than for short duration. The old meters, he said, did not measure that dimension of sound."The people who were creating the commercials learned how to exploit the meters and fly below the radar," Lund said. The result: blaring ads.
Lund's company is one of several suppliers of advanced metering devices that stations and cable and satellite TV operators have installed in advance of Thursday's deadline.
Most broadcasters have been been preparing for the new law, so the frequency of excessively loud ads has diminished during the past year.