Friday, April 18, 2008

The HiFi Myth

Compact disks and digital music downloads of similar quality may be with us for a long time. We have superior digital audio formats, several of them in fact. It looks like that won't matter, however, because humans can't hear the difference.

A recent study by David Moran and Brad Meyer, published in the September 2007 Journal of the Audio Engineering Society, shows that under controlled conditions most people can not hear the difference in sound quality between compact disk audio and technically superior digital audio.

The study went something like this. Two different audio signals were sent to the same amplifier and speakers. One was the direct output from a high resolution DVD audio source. The other was the same signal digitally reduced to compact disk specifications (16-bit, 44.1khz).

The listener was given a three position switch that controlled which source was sent to the amplifier and speakers. One position was the high resolution audio. Another was the CD quality audio. The third position was one or the other, but not labeled. The listener was asked to identify which of the first two signals the third matched. Listeners' success in doing this was similar to the expected results of random guesses.

A similar study was done about twenty years ago by Stereo Review (now called Sound And Vision) magazine. This study used a three position switch to select amplifiers which were adjusted to the same conventional home listening volume. The study paired very expensive home stereo amplifiers with more modest ones. The results showed that when used in the way home stereos are almost always used people could not hear the difference between $100 home stereo amps and $1000 ones.

All of this makes me feel really good about never getting around to putting a new stereo in my van. Likewise, it validates my decision to use the same crappy computer speakers for the last six years. It also takes some of the wind out of the laments coming from producers and sound engineers about everybody listening to their hard work in MP3 format on $10 ear buds that bury or strip away so much of their brilliance.

More importantly it all means that it never mattered in the first place.

Years after the first time I listened to "Private Investigations" by Dire Straits I happened to be killing time in a small recording studio and put it on the monitors just to have something to listen to. The monitors in question happened to be the largest, best sounding JBL's I'd ever seen. I had never heard the footsteps in the background of the track before and thought it was an awfully cool touch.

This raises two questions. First, of all of the people who have listened to this song (the original studio version on Love Over Gold, not the live one on Alchemy) how many of us have heard the footsteps? Second, does it matter?

As much as I enjoyed my Dire Straits experience in the studio that day it didn't change the way I felt about the song, the album or Dire Straits. I thought Love Over Gold was some of Mark Knopfler's greatest work before that day and I still do. The footsteps are just a bonus.

I would say that none of it matters much. Super high sound quality is for movie theaters and steps during the production process, to preserve as much nuance as possible before dithering the signal down to its delivery format. The finished product is going to be heard in CD quality or lower even if it is delivered in a format technically superior to that.

Everything else is for hoovering money out of the pockets of people who don't know they won't hear the difference.

No comments: