9.2 Human Performance And Limitations - Hearing

Question 1

what is the functions of the ear?

Answer 1

detect sounds through vibrations in the air
responsible for balance and sensing accelration

Question 2

what are the 3 divisions of the ear?

Answer 2

outer ear
middle ear
inner ear

Question 3

what is the purpose of the outer ear?

Answer 3

direct sounds down the auditory canel to the ear drum causing it to vibrate

Question 4

what is the purpose of the middle ear?

Answer 4

beyond the eardrum, which transmits vibrations by the way of 3 bones called ossicles, to the fluid of the inner ear

Question 5

what are the names of the 3 bones called in your ear?

Answer 5

hammer
anvil
stirrup

Question 6

a muscle is also found in the middle ear, why is this?

Answer 6

to protect the ear from sounds over 80dB by acoustic or aural reflex

Question 7

what is the limitation of acoustic and aural reflex?

Answer 7

cannot provide protection from sudden noises and only for up to 15 minutes

Question 8

what is the middle ear filled with? whats its limitations?

Answer 8

air

eustachian tube can be filled with mucus as its connected to the nose and mouth

Question 9

what is the inner ear filled with?

Answer 9

fluid

Question 10

what is the last of the ossicles connected to in the inner ear?

Answer 10

the cochlea

Question 11

how are nerve impulses transmitted to the brain?

Answer 11

once the cochlea detects vibration due to the motion of the fluid, they are sent via the auditory nerve

Question 12

what does the amount of vibration detected mean?

Answer 12

the amount detected depends on the volume and pitch of the sound

Question 13

what is the frequency range that a young person can hear?

Answer 13

20 and 20000 cycles per second (Htz)

Question 14

what impact can negative effects have on performance? (5)

Answer 14

-can be annoying (sudden sounds or constant loud sounds)
-interfere with verbal comms
-cause accident by masking warning signals
-be fatiguing and affect concentration and decision making
-damage workers hearing

Question 15

what sort of noise is generally more disruptive?

Answer 15

intermittent and sudden noises

Question 16

what is the regulation covering hearing at work?

Answer 16

control of noise at work regulation 2005

Question 17

what is the aim of the control of noise at work regulation 2005?

Answer 17

to ensure workers hearing is protected from excessive noise at their place of work which could cause them to lose their hearing or suffer from tinnitus

Question 18

at what level must employers provide hearing protection?

Answer 18

85dBs

Question 19

at what level must employers assess the risk to workers health and provide with information and training?

Answer 19

80 dBs

Question 20

what is the exposure limit?

Answer 20

87dBs when wearing hearing protection

Question 21

what is noise dose?

Answer 21

exposure to any sound over 80dB and measured over an 8 hour day time-weighted average

Question 22

what is the maximum TWA?

Answer 22

90 dB

Question 23

what could occur if the TWA were to exceed 85dB for 8 hours?

Answer 23

hazardous and lead to damaging the inner ear

Question 24

what can hearing protection interfere with?

Answer 24

verbal communications

Question 25

what is hearing loss known as?

Answer 25

noise induced hearing loss (NIHL)

Question 26

what causes NIHL?

Answer 26

the hair-like cells on the basilar membrane being damaged beyond repair

Question 27

why is it difficult to notice hearing loss?

Answer 27

as it occurs gradually and by the time you notice, you are too late

Question 28

what is the term for when hearing deteriorates with age?

Answer 28

presbycusis