The eardrum then starts vibrating and these vibrations are passed to three small ear bones – called the hammer, anvil and stirrup. Many animals have ears that are able to detect ultrasound.

A study of the inner ear bones of Neanderthals shows a significant loss of diversity in their shape around 110,000 years ago, suggesting a genetic bottleneck that contributed to Neanderthals' decline.

Other issues found in multiple skulls included poorly healed or malformed jaw bones and one Viking skull showed signs of hardened tissue near the temporal bone, which may indicate an ear infection ...