Photo: dittomusic.com

Rave parties go crazy when the bass drops, no doubt about it, but what makes people click so well with low frequencies? Canadian scientists at the McMaster Institute for Music and the Mind investigated how our brains react to low-freq pitches and found our affinity has to do with how humans detect rhythm. Basically, the bass is easier to follow, so more enjoyable.

“There is a physiological basis for why we create music the way we do,” study co-author Dr. Laurel Trainor, a neuroscientist and director of the institute, said. “Virtually all people will respond more to the beat when it is carried by lower-pitched instruments.”

Trainor and colleagues strapped 35 people with an electroencephalogram (EEG) to monitor their brain activity and played them a sequence of low and high-pitched piano notes at the same time. Sometimes, the notes were played 50 milliseconds too fast, but most people would recognize the offbeat in the lower tone, instead of the high pitch or both.

Then, the researchers prepared an experiment that investigated the participants’ unconscious reaction to rhythm. The volunteers were asked to tap their fingers to the beat and when the timing change occurred, the researchers noticed that the people were more likely to modify their tapping to fall in sync with the low-pitched tone.

Finally, the researchers played the same sequences through a computer model of the human ear. The analysis showed that recognized the offbeat in the low-pitched tone more often than it did in the higher tone. This suggests that the ear itself, not some brain mechanism, is responsible for this effect.

This study “provides a very plausible hypothesis for why bass parts play such a crucial role in rhythm perception,” Dr. Tecumseh Fitch, a University of Vienna cognitive scientist who did not participate in this research, told Nature.

The findings were published in the journal PNAS.