Question 20N.3.SL.TZ0.6c
| Date | November 2020 | Marks available | [Maximum mark: 3] | Reference code | 20N.3.SL.TZ0.6c |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Describe | Question number | c | Adapted from | N/A |
The hearing threshold is how loud a sound needs to be before an individual can perceive the sound. The chart shows the mean value of the hearing threshold for hearing-impaired individuals before and after receiving a cochlear implant. Normal human speech has a range of loudness of from 50 to 60 decibels (dB).
[Source: This article was published in Brazilian Journal of Otorhinolaryngology, Volume number
81, issue 2, Caixeta Guimarães, A., Machado de Carvalho, G., Duarte, A.S.M., Bianchini, W.A., Bravo Sarasty, A.,
di Gregorio, M.F., Zernotti, M.E., Sartorato, E.L., Menino Castilho, A., Hearing preservation and cochlear implants
according to inner ear approach: multicentric evaluation., pp.190–196 , Copyright Elsevier (2015).]
Describe the normal function of the cochlea.
[3]
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;
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.
