Outline the effect of the cochlear implant on hearing.

Suggest, with reference to the structure of the ear, a reason that a cochlear implant requires an amplifier.

Describe the normal function of the cochlea.

a. the implant lowered the threshold of hearing
OR
allowed quieter sounds to be heard;

b. the person would be able to hear human speech;

the implant is not connected to the bones (whose function is to amplify sound)
OR
the implant bypasses the middle ear
OR
the amplifier replaces the function of the bones

a. vibrations cause fluid in the cochlea to move;

b. (movement of fluid) causes stimulation/movement of haircells/mechanoreceptors;

c. higher frequency is detected closer to the base of the cochlea / vice versa
OR
each frequency stimulates specific hair cells;

d. hair cells generate impulses;

e. connected to the brain by the auditory nerve;

Many candidates correctly stated that the cochlear implant lowered the hearing threshold, but fewer stated it would allow human speech to be heard.

The need for an amplifier as the bones of the middle ear were bypassed was noted by the stronger candidates.

Candidates get confused when describing the function of the cochlea. Most know there is fluid and there are hair cells, but answers were often confused. Only the better candidates stated that hair cells respond to different frequencies of sound.