1.5) Sense of Hearing & Sound

Parts of Human Ear

(i) outer part a) Pinna:

b) Auditory canal/ear canal

c) Ear Drum

(ii) Middle Ear-Ear Bones or Ossicles

Amplify sound vibrationsampl

-Oval Window(send vibration to the inner ear, make

the fluid in cochlea vibrates)

E

-Eustachian tube

iii) Inner Ear-cochlea

-detects vibrations-convert vibrations into nerve impulse

-Auditory nerve(send the nerve impulses to the brain for

interpretations)

The hearing Mechanism???

How do we hear?(refer to cd courseware)

Sound and hearing1.How is sound produced?-sound is produced by ………………

2. Whenever an objects vibrates, its kinetic energy is changed into ………………energy

Kinetic energy (sc.pract pg 27)

Transmission of sound-sound travel through a medium

-sound travel through:i) solidsii)liquidsiii) gases

-sound travels very fast through solid and slowest through gas. WHY???

(particles in solid is very compact, sound vibrations can pass very quickly form particles to particles)-sound cannot travel through VACUUM-Ex:1) loud explosions which takes place in the Sun cannot be heard on the earth,WHY???(there is a large vacuum between the sun and the earth)