Human brains more sensitive to sounds than monkeys

Curious as to how human brains process auditory stimuli when compared to primates such as the rhesus macaques, researchers from MIT and the Laboratory of Sensorimotor Research studied three rhesus macaques and four human participants.

Utilizing MRI imaging, the researcher team measured the monkey and human brain responses to harmonic tones and noise that included five different frequency ranges. The initial review of the MRI scans didn't reveal differences in the brain responses between human and monkeys but a more detailed examination showed that the human brains were much more sensitive to "pitch" in harmonic tones than the macaques. Human brains were also more responsive when tonal structures were added to the sounds. Even when the researchers exposed the macaques to natural sounds such as recordings of macaque calls, the results were the same.

The study results point towards the macaques experiencing music and other sounds differently and possibly explains why it is hard for scientists to train monkeys to perform auditory tasks, which humans can handle with ease.