Animal Hearing Range

1. F S+ AW + A W

2. A Human can hear frequencies that
range from 20Hz to 20,000Hz.
Sounds are made by something
moving backwards and forwards.
This is called Vibrating
When a man speaks his vocal cords
vibrate this makes the sound travel,
so when someone else picks up the
vibration they can then hear what
they are saying.
Sound waves travel through the air
and into the ear, making the eardrum
vibrate. These vibrations then cause
the 3 small bones in the ear to
vibrate and these in turn cause the
liquid inside the cochlea to vibrate.

3. Today we know that dolphins produce clicks
using nasal sacs.
The sounds reflect off objects and are picked up
again in the dolphins lower Jaw
The reflected sound waves travel through a
channel filled with fat and then into the ear.
Like light waves, sound waves can be focused,
and dolphins have a “lens” made of fat that they
use to focus on sound waves.
Sound waves that have a frequency above
20,000hz (the upper limit of human hearing) are
called ultrasound.
However dolphins are only known to emit sound
waves within frequencies up to about 150 kHz
where as ultrasound use waves of 1-20mhz.