The correlation between ability to discern the difference between the Santana recordings and headphone use was -.01, not significantly different from zero. So if the people who used headphones were better able to discern the differences in the recordings, then we might be able to attribute the difference to equipment. Some listeners didn't have headphones, and just listened to the Santana with their speakers. We asked respondents to listen to the Copland recordings using their computer speakers, and to the Santana using headphones. One possibility is that the people who can't hear the difference don't have sensitive enough speakers and headphones. Do they really hear something the rest of us can't? Still, that's less than five percent of our listeners. In fact, 33 of our respondents were able to successfully rank both recordings, rating the higher data rates as better quality. But there are a few other possibilities.įirst of all, it might not be true that everyone can't tell the difference between 128 kbps and 256 kpbs data rates. Are they simply wasting our disk space? So far these results suggest they are.

Recently launched a digital music service which boasted 256 kbps MP3s, instead of the 128 kbps files more common at other sites. The real question we're trying to answer is 'how big is big enough?' A balance must be struck between a compact file size and audio that sounds good. But obviously this process can't work forever. The MP3 algorithm works by attempting to remove parts of the sound that you're less likely to detect.

A 64 kbps MP3 contains half as much information (and consumes half the disk space) of a 128 kbps MP3. This means that some of the information in the original digital recording is removed in order to make the file smaller. MP3's are 'lossy' methods of digitally encoding audio files. If you're not familiar with data rates, here's a brief primer. It's looking like the 256 kbps MP3s offer no advantage over the much smaller 128 kbps MP3s. For both recordings, there was a significant difference between ratings of the 64 kbps data rate and the 128 kbps data rate, but no difference between ratings of the 128 and 256 kbps data rate.

Each recording was encoded into an MP3 file at three different data rates: 64, 128, and 256 kbps. Respondents rated two recordings, one by rock guitarist Carlos Santana, and another by orchestral composer Aaron Copland. So does a very high data rate result in a noticeable difference? Here our are basic results: Two weeks ago, we challenged our readers to see if they could discern the difference between MP3 recordings at different sampling data rates.

Is 128 kbps good enough