How We Hear
we detect sounds, or noise, our body is changing the energy in sound waves into nerve
impulses which the brain interprets. SOUND WAVES are produced when
the air is mechanically disturbed.
is measured by its:
- frequency - This
is the pitch (high or low) of a sound -- the number of complete sound wave cycles each
second. High frequency noises are more damaging to hearing than low frequency
- intensity - This
is the loudness of a sound. It's measured in decibels (dB).
When we hear a sound, this is what actually takes place:
- SOUND WAVES enter
the ear canal and cause the eardrum to vibrate.
- VIBRATIONS pass
through 3 connected bones in the middle ear
- This motion SETS FLUID MOVING
in the inner ear.
- Moving fluid bends thousands of delicate hair-like cells which
convert the vibrations into NERVE IMPULSES.
- Nerve impulses are CARRIED
to the brain by the auditory nerve
- In the brain, these impulses are CONVERTED
into what we "hear" as sound.
Now we will learn more about noise levels and their impact on our ability