Cats Purr at a Healing Frequency
Cats' purrs are beneficial for them, but they're also beneficial for humans. When cats purr, their brains release endorphins, but the brain of a human in proximity to a purring cat may also release endorphins. That may not be surprising to people who love cats.
More surprising perhaps is that the frequency at which cats purr (between 25 and 150 Hz) has been shown to have healing properties – both for cats and for humans.