Do you jump when you hear a loud noise?  Do you feel happy when the opening music for your favorite TV show starts playing?  Do you feel sad when you hear a baby crying?  The sounds in our world play a big part in our lives.  They teach us, entertain us, guide us and help make us who we are.  Hearing helps us to communicate with the people and animals around us which is an important part of our everyday life.  When our hearing is not working right, communication gets a lot harder.  Hearing and our ears are an important part of our lives.


Our auditory system is made up of all the parts of our body that help us to hear.  The system has three sections: the outer ear, the middle ear, and the inner ear.  Each part plays an important role in getting sound to our brains.  Hearing happens when our ears pick up a sound, and our brain gives the sound meaning.  That's how we know that it is a dog barking in our neighbor's yard and not a cat.  Our brains know that cats don't bark.  When we hear a train whistle, we know a train will be coming soon.  If one of the three parts of our system stops working, we would not be able to hear well, and we could miss out on some information we might need to know.  Let's take a look at the outer ear and see how it helps us to hear.


Before our brain can give meaning to a sound, the sound has to get to the brain.  That's where the pinna comes in.  The pinna is the part of the ear we see on the outside of our heads.  It's what you use to hold up your sunglasses, to hang an earring on or tuck your hair behind, but the pinna is much more than that.  The pinna is a funnel that catches sound in the air and directs it into our ear.  Think about trying to pour water into a bottle from a glass.  Some of the water will go into the bottle but lots will end up outside the bottle or even on you!  Now think about doing the same thing but using a funnel this time.  You can usually get all the water into the bottle.  This is how the pinna works with sound.  It gets all the sound it can into our ears.  This helps us to hear two to three times more than we would if we just had small holes on the sides of our head.  It also tells us what direction a sound is coming from.  If you watch a cat, they turn their ears this way and that to catch sound, but our pinna works so well that we don't have to turn our head to know that a sound is coming from behind us.

A funnel can capture material over a wide area and concentrate it just like our pinna.

Even though some people can wiggle their ears around, most of us cannot, but our ears can bend.  They can bend because they are made up of a bendable tissue called cartilage.  It is a lot like bone but softer.  Cartilage is a bendable tissue that is found in many parts of the body.  It is not as hard as bone but still helps to keep things stiff.  That means our ears stay up on the sides of our heads and do not flop over like some dogs' ears.  Because our ears are on the outside of our heads, it is helpful for them to be more soft and be able to bend.  It might be pretty painful to put your head on a pillow if your ears were made of bone instead of cartilage.

After the sound has been caught by the pinna and directed into our ears, the next place it moves to is through is our ear canal.  The ear canal is a tunnel that runs from the outside of our head to the ear drum.  It is about 3.5 cm long and about 0.7 cm wide, not very big, but it has a big job.  That job is to let the sound in and keep everything else out!  To do that, there are some important safety features built into the ear canal.  That nasty brown sticky stuff that comes out of our ears is made in the ear canal.  This goo we call earwax protects the skin inside from damage.  And because it is so sticky, it also catches dirt and dust and keeps them from reaching our eardrum.  It is even poisonous to some small bugs that might want to crawl into our nice dark warm ears.  The walls of the ear canal are also lined with tiny hairs that catch dirt and germs that might cause ear pain.  Anything that gets inside our ears can block sound waves which means we won't hear as well.

Dogs have amazing hearing despite their floppy ears.

The outer ear is a pretty important piece of the puzzle when it comes to hearing.  The pinna and the ear canal work together to bring music, voices, and all kinds of sounds into our lives.  Sometimes we forget how important it is to be able to hear.  It is so important that dogs are trained to help people with hearing trouble.  These dogs can save lives by telling their master if a fire alarm is ringing or a tornado siren is blaring.  It is important to keep our hearing safe by not listening to loud noises, taking care of ear pain quickly and keeping our ears clean.  If we take good care of our ears, we can keep them in good working order for many years to come.