The case for compressed audio

Shonver · Mar 27, 2009

The articled linked to by Rodney_gold got me thinking.

March 18, 2009 It seems that most people are content with the performance they get from their white iPod earbuds (and let's face it, most standard issue headphones that come with portable music players) ? subpar audio in a convenient package. Has the performance of a humble set of headphones been forgotten in favor of something more compact, and to some more fashionable? Yes is the answer according to an informal study by Stanford Professor of Music, Jonathan Berger, and apparently it doesn't end there - young people actually prefer the ?sizzle? sound of MP3?s.

Berger runs an informal test of his students each year by playing a range of different music in a number of different formats. Students were asked to judge the quality of a variety of songs using different compression methods mixed in randomly with uncompressed 44.1 KHz/16 bit audio. The examples included both orchestral, jazz and rock music.

Initially, Professor Berger was expecting to see a preference for uncompressed audio and expected to see the MP3 format (at 128, 160 and 192k bit rates) preferred well below other compression methods (including a proprietary wavelet-based approach and the AAC format.)

To his surprise, in the rock examples he played, MP3 at 128 kb/s was preferred! Repeating the experiment over a six year period, he found the preference for MP3, particularly with high energy music (cymbals, brass hits and the like) is rising over time.

So it seems younger people haven?t just grown more tolerant of thin, clinical sounding compressed versions of their favorite tunes, they actually like them! Despite it being one of the first, MP3 is not the best compression method around, and 128 and even 96kb/s versions are very common. Professor Berger is quoted as saying it?s the "sizzle sounds" that young people love because it's what they're comfortable with.

The research is of course very limited, bven this informal study raises some interesting food for thought. The technology is here to stay and as the iPod generation gets older it could be that quality audio reproduction wont be the highly sought after commodity it's seen as today. Formats like SACD and DVD Audio (and even the humble CD) shrink further into obscurity, but sadly not because they?re considered too bulky and inconvenient but simply because they just sound too true to life. Scary!

The high resolution, wide dynamic range aspect of high quality recordings can only be appreciated by listening to it through equipment capable of reproducing those details. Most consumer equipment do not resolve the details. One way to get mainstream audio equipment to play low level detail is to reduce the dynamic range of the signal; essentially boosting low level detail to the level of being comparably loud wrt the louder passages. Not surprisingly, high fidelity recordings do not impress the man in the street; its value is not apparent because most equipment cannot reproduce it faithfully.

Conversely, listening to highly compressed audio on a high performance audio system is an unpleaseant experience. The reason being that the two are incompatible. Most popular recordings compensate for the non-linear dynamic behaviour of budget gear (probably unwittingly) by applying compression. This is of course not required with better equipment. So both camps are dissatisfied with the other's material... but the point of my post is that there is a place for both schemes.

;D ;D ;D