Detecting Sound

To explain how the human ear detects sound, we first have to look at the structure of the ear:

1. The outer ear is called the pinna. It funnels the sound waves the ear receives and sends the waves down the ear canal, which is part of the middle ear.

2. These soundwaves travel through the ear canal and reach the eardrum, which makes the eardrums vibrate. Microphones contain a diaphragm, which works in a similar way to our eardrums, which are part of the inner ear.

  • Three small bones in the inner ear are connected to the eardrum, which are the hammer, the anvil and the stirrup.

3. The three small bones pass the vibrations onto the next part of the ear, the cochlea (the snail shaped organ).

4. Movement then begins to happen in the fluid inside the cochlea.

  • There are tiny hairs inside our cochlea which move and detect the movement of the fluid in the cochlea

5. These dancing hairs inside the cochlea convert the movement from sound waves to electrical signals.

6. The electrical signals are transported to the brain up the auditory nerve.

7. The brain translates the electrical signals to sound, which we can recognise and understand.


The loudness of sound is measured in decibels (dB)

The average conversation is usually around 60 dB

The average concert is around 115 dB

Keep in mind, an increase of 10 decibels means the sound is ten times louder.

Hearing Damage

A busy street is around 80dB and that is enough to cause hearing damage, after continuous exposure.

This is why workers who are exposed to loud sounds for long periods of time should wear ear protection.