Background:
Compact discs have permanently changed the way people listen to, store and record music. Though the uses for them have expanded since their initial release in the late 1970’s and their popularity has declined considerably since the invention of the mp3 and related music players, they are solely responsible for the digital music revolution. Analogue music recorded on vinyl records had its own advantages and disadvantages. Of the most concern here is a portability and shock resistance issue that simply could not be overcome due to the method of encoding and reading used to store the audio information on records. Compact disks overcame both of these issues, though the differences in data storing allowed for new approaches to mixing and mastering recordings. These mixing and mastering trends in turn have changed people’s preferences for recording style. People have come to expect certain qualities from the audio they listen to, qualities which often were not present on recordings made decades ago. Thus, when songs are rereleased, they are often remastered to cater to more current acoustic preferences.
Due to the physical limitations of needle vibration within the grooves of the record, an inherent volume limit to recordings was imposed on records. However, even during the days of turntables, louder recordings tended to attract more attention in situations where sound quality was not as apparent (radio/ jukeboxes). Thus, recording studios would make their recordings as loud as possible in much the same way that television stations tend to make the commercials louder than the actual program. People have a tendency to equate louder music with higher quality recordings (a tendency supported by our testing. Many of our subjects stated that one side sounded better simply because it was “louder”). Upon the introduction of the compact disk, this physical limitation was removed allowing for much louder music. The change wasn’t immediate. It took many years.
Rather than merely upping the volume of the entire track, a practice called compression is often used. Compression takes the quietest sounds and makes them louder while softening the louder sounds. Because it is easier to more clearly discern louder sounds, people will often equate better sound quality with a song that has less dynamic range. You can more easily hear softer sections of music in a more compressed track. Ironically, compact disks were marketed for their potential for greater dynamic range (complete silence could be achieved as no needle noise is involved). However, such changes to audio after it is recorded can cause distortions or clipping. The most drastic changes to audio compression trends occurred between 1990 and 2000.
We set out to test whether the volume itself was the source of perceived increase in musical recording quality over the years, or if the clipping and distortion caused a significant decrease in perceived quality when volume was adjusted for.