Sunday, January 9, 2011

Compressed Audio

Here are two articles talking about compressed sound, i.e. the sound of an mp3 being played by your computer or iPod.

The first is from one of those TED talks which are over the 'net, but which don't work on dial-up. For this one, though, there's a text synopsis. The title is Ten Things You Didn't Know About Sound. Here's #7 on his list:

Compressed music makes you tired. However clever the technology and the psychoacoustic algorithms applied, there are many issues with data compression of music, as discussed in this excellent article by Robert Harley back in 1991. My assertion that listening to highly compressed music makes people tired and irritable is based on personal and anecdotal experience - again it's one that I hope will be tested by researchers.

From personal experience, I agree that listening to compressed audio is tiring, and for me, annoying as well. One reason I gave up TV years ago is the very unpleasant sound they make. What I'm not sure of is how other people experience compressed sound. My hearing is very acute when it comes to the quality of audio (I could never listen to cassette tapes during their day), whereas I was totally at sea trying to hear the inner voices of four part harmony in ear training back in conservatory days. Your brain wiring may vary.

The second article deals with how new technology looks to make highly compressed sound a thing of the past. For one thing, there are newer digital to audio converters with which:

the conversion from a digital signal (0's and 1's) to analog sound waves (which your ears can hear) is handled by a device that's been manufactured to do only that, and to exacting standards. This alone should make a dramatic difference.

Another thing is that increasingly you'll be able to download mp3 files that are less compressed than the current standard.

But you can also adjust the settings on your computer so that it downloads iTunes songs (and other music files) at higher bit and sampling rates. Again, if you want to listen to this music only on your computer or iPod, this won't matter much; but if you want to stream it to your home stereo, this step alone will make a big difference. (If you're thinking of downloading music at higher bit and sampling rates, you may need to buy an external storage device to hold the extra data. They're cheap these days: about $100 for something that holds a terabyte of data.) A few companies out there are selling music-downloads at bit and sampling rates that exceed even those of CDs.

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