The ear emits measurable echoes requiring active neural involvement

Evidence

When a sound is presented to the ear, an echo can be recorded. The echo can be delayed so much (> 10 ms) that it cannot be explained by passive mechanics of the ear but neural systems must be involved. The resulting motion causes a faint sound, which is propagated back out of the ear and can be registered after stopping the acoustic stimulus. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 775