Friday, May 29, 2009

Is it the end of the Loudness War?

We all know the scenario... you are at home, relaxing, watching TV (for those that haven't yet grated to the net) and relaxing watching your program then click the ads come on and you're diving for the remote to turn down the, all of sudden, screamingly loud TV. Ads can be perceived to up to 10dB louder than normal program material meaning they can sound over twice as loud.

Well the end may be in sight. The Communications Research Centre in Canada (CRC) loudness meter has been accepted as the international standard. There is a very good article on the website about the reason behind varying loudness of program material. It also details the research carried out to come up with an agreed standard for subjective loudness metering. Based on the data the CRC designed their own loudness meter and tested it against other loudness meters already in existence.

According to the report what made the finding so surprising was that Soulodre's meter was so simple. "While some of the meters modeled the complex interactions between sound waves, the ear and the brain, Soulodre's algorithm filtered out low frequencies from the loudness calculation and averaged the power of what was left."

"What it means," says Thibault (manager at CRC), "is that when you're adjusting the volume on the TV your ear acts as a high-pass filter: it's less sensitive to the low frequency sounds. Because your ear is more sensitive to the higher frequencies, especially those between 100 Hz and 8 kHz - the dominant frequencies in human speech - you base your volume calculation on the loudness of these higher frequencies."

3 comments:

mellows said...
This comment has been removed by the author.
mellows said...

That's interesting, though I doubt it will affect little old us in South Africa... :) If only something similar would be done in the music industry; see my blog post on the subject.

AudioLemon said...

HI mellows cheers for the link to your post... hadn't seen the second vid. It is depressing really.