Question

Match column I with column II and select the correct option from the given codes.

Column I	Column II
A. Pinna	(i) Collects vibrations in the air which produces sound
B. Ear canal	(ii) Passage for sound wave from pinna to ear drum
C. Tympanic membrane	(iii) Transfers sound wave to ear ossicles
D. Ear ossicles	(iv) Increases the efficiency of transmission of sound waves to the inner ear
E. Cochlea	(v) Has hearing receptors
F. Eustachian tube	(vi) Equalises the pressure on both sides of ear drum
G. Auditory nerves	(vii) Impulse transfer from organ of Corti to auditory cortex in temporal lobe of cerebrum

• A. A - (i), B - (ii), C - (iii), D - (iv), E - (v), F - (vi), G - (vii)
• B. A - (vii), B - (vi), C - (v), D - (iv), E - (iii), F - (ii), G - (i)
• C. A - (i), B - (ii), C - (iv), D - (iii), E - (v), F - (vi), G - (vii)
• D. A - (i), B - (ii), C - (iii), D - (iv), E - (v), F - (vii), G - (vi)

Answer 1

The correct option is A A - (i), B - (ii), C - (iii), D - (iv), E - (v), F - (vi), G - (vii)

A. Pinna: It collects sound waves and directs them into the external auditory canal.

B. Ear canal: It follows an oblique course so as to prevent hard objects from hitting the tympanum directly.

C. Tympanic membrane: The tympanic membrane begins to vibrate at the same frequency as that of the sound waves. From it, the vibrations are transmitted across the tympanic cavity by the ear ossicles.

D. Ear ossicles: From ear ossicles sound transfer to the membrane of the fenestra ovalis. The force of vibrations is considerably increased in the middle ear by leverage of the ossicles.

E. Cochlear: The receptor cells at the base of the cochlear duct are stimulated by the sounds of high frequency.

F. Eustachian tube: At the pharyngeal opening of the eustachian tube is a valve which normally remains closed. The valve opens during yawning, swallowing and during an abrupt change in altitude when air enters or leaves the tympanic cavity to equalize the pressure of air on the two sides of the tympanic membrane.

G. Auditory nerves: The receptor cells at the base of the cochlear duct are stimulated by the sounds of high-frequency Loudness of the sound is perceived by the rate of nerve impulses reaching the brain.

So, the correct answer is 'A-(i), B-(ii), C-(iii), D-(iv), E-(v), F-(vi), G-(vii)'.