How Good is a Rats Hearing?

If you’re wondering how good a rats’ hearing is, it might surprise you to learn that they don’t have the same sensitivity to sounds as humans. Rats can hear only about half as many frequencies as humans can, so they struggle to hear low-frequency noise. A typical human can detect a range of frequencies between two decibels and twenty kHz. To test this, the researchers recorded the response of the animals’ cochleas to tones. Normally, the cochlea amplifies sound information, but they didn’t find any amplification in either species of mole rats.

In 1954, Professor John Anderson recorded the sounds made by rats. The recordings included a series of tones that ranged in frequency from 20 to 80 kHz. The sounds were more like calls than speech, and were similar to those made by bats or guinea pigs. Further work has shown that rats have a vast repertoire of vocalizations, including those that mimic human speech. Some have even been observed laughing when tickled.

In addition to auditory tests, researchers have proposed various protocols for testing the hearing abilities of rodents. These protocols use different methods to measure the auditory thresholds. While behavioral audiograms are comparable to human audiometry, other methods are quicker and less complicated.