Ears aren’t just funny looking things on the side of our heads – they are super clever sound devices. Here, Superhailer’s acoustics expert Matt Henry picks out his 16 top facts about our hearing system.
1. Ears are funnels that allow us to hear even tiny sounds. They act as a bridge for sound waves to pass.
2. As sound waves enter the inner ear tiny bones called the hammer, anvil and stirrup and the eardrum all begin to vibrate. Sound vibrations then pass through the cochlea – a shell-like chamber that’s filled with fluid. These sound vibrations stimulate tiny hairs that are attached to our hearing nerve – which then sends the sounds to our brains.
3. If we lost those tiny hairs, we would be completely deaf.
4. Our ears send everything they ‘hear’ to the brain unfiltered. Our brains are so clever they can sort out this confusion of inputs into recognizable sounds – speech, music, laughter, thunder etc.
5. Our sense of balance is all thanks to our ears. The vestibular system is found in the inner ear and maintains our equilibrium.
6. The hammer, anvil and stirrup bones are the smallest in our bodies – they could all fit on a penny. The ear is also home to the hardest bone in our body – the temporal bone that protects the inner ear.
7. Earwax may be yucky but it’s doing a good job – it catches dirt and protects the inner ear from bacterial and fungal infections – so leave it alone!
8. Ever wondered how we ‘unblock’ our ears? It’s thanks to a 3.5 cm tube that goes from behind our nose to our middle ear. It helps to balance pressure and is the source of the sensation of your ears popping.
9. Our ears get no rest – they are always listening. When we sleep our brains can mostly ignore what we hear – listening again only if a loud or unusual sound is heard. How cool is that?
10. The biggest cause of hearing loss is overexposure to loud sounds. Sitting in front of a speaker at a pop concert can be as loud as 120 decibels. At this volume some people can start to experience hearing damage after less than 10 minutes of exposure.
11. The Superhailer loud hailer (pictured), can project crystal clear messages and sounds up to 800 ft (250 m). But thanks to clever technology it’s never too loud. Before it transmits any sound an inbuilt range finder instantly measures the distance to the target. This information is fed to the onboard safety limiter to determine what the safe volume level should be.
12. Our ears have biases. Our left ear is more receptive to music, while our right ear responds better to speech!
13. Dogs know you are home before everyone else because they can hear a higher frequency than humans. But cats are better (of course), hearing even higher frequencies – and they can rotate their ears 180 degrees.
14. Dolphins may not have ears, but they can hear huge distances – up to 15 miles. They have external eardrums and use sonar to supercharge their hearing power.
15. Some insects can hear, others not. The mosquito hears thanks to tiny hairs on their antennae, while the poor old fly can’t hear a thing.
16. Elephants can hear super-low frequencies – more than 20 times lower than us. Their ears may be ginormous, but they also use their trunk and feet to detect sounds.