1. Ear and
the hearing process

2. The ears
The structure of an ear
Outer ear
Middle ear
Inner ear
The hearing process

3. The ears one of the 5 sense organs detect sound
provide the sense of hearing
help to detect the movement of the body
help to keep the balance of the body by detecting the position of the head

4. The structure of an ear Divided into 3 parts: outer ear middle ear
inner ear

5. Outer ear Consists of 3 structures: ear pinna
collects and directs sound waves
ear canal
directs sound waves to eardrum
eardrum
vibrates when hit by sound waves

6. Middle ear Consists of 4 structures: ear bones 3 ear bones
amplify sound vibrations
pass on vibrations to oval window

7. Middle ear Consists of 4 structures: ear bones
transmits sound vibrations to inner ear
oval window

8. Middle ear Consists of 4 structures: ear bones
releases pressure from sound waves
oval window
round window

9. Middle ear Consists of 4 structures: ear bones
equalizes pressure on both sides of eardrum
oval window
round window
Eustachian tube

10. Inner ear Consists of 2 structures: semicircular canals
contain sensory hair cells
detect the directions of head movement

11. Inner ear Consists of 2 structures: semicircular canals cochlea
contains sensory hair cells which
detect pressure changes and produce nerve impulses

12. The hearing process 1 The ear pinna collects sound waves.
Sound waves pass along the ear canal.

13. The hearing process
2 Sound wave makes the eardrum vibrate.

14. The hearing process
3 Ear bones move to amplify and transmit the vibrations to the oval windows.

15. The hearing process 4 Oval window vibrates and
5 makes the perilymph in the cochlea vibrate.

16. The hearing process
6 Perilymph transmits vibration to endolymph.

17. The hearing process
7 Sensory hair cells in endolymph are stimulated and send off nerve impulse.

18. The hearing process
8 Auditory nerve transmits nerve impulses to the brain.

19. The hearing process
9 Auditory centre interprets the nerve impulses.

20. The hearing process
10 Pressure built up in perilymph is released at the round window.

21. Summary The structure of an ear ear bones semicircular canals
ear pinna
ear canal
eardrum
oval window
round window
cochlea
Eustachian tube

22. The hearing process
Collection of sound waves
 transmission of sound waves
 amplification of sound waves
+ vibration of body liquid
 detection of vibration
 transmission of nerve impulses
 interpretation of nerve impulses
 sensation of hearing