How can bats hear such high frequencies?

Question

I attended a talk that glossed over some biology as it was talking about a certain protein. The speaker mentioned humans can hear up to, often less than 20kHz frequencies, whereas bats can hear up to 100kHz. Presumably this is to do with differences in cochlear anatomy. What about the inner ear of bats is different form ours, and how does this allow them to hear such high frequencies?

Answer 1

A high concentration of receptor cells located in the bat's inner ear detect the higher frequencies. Their middle and outer ear aids in this phenomenon as well. A physiological adaption in their middle ear separates the middle ear bones (malleus, incus, and stapes) to prevent damage from high frequency sound, With its many wrinkles and folds, the outer ear is speculated to aid in their hearing perception as well.