10

Question 1

use of sensitivity

Answer 1

Helps survival of living things (escape from danger, search for food & find mates)

Question 2

Stimuli

Answer 2

changes in the environment that cause a response

Question 3

sense organs

Answer 3

body parts in human bodies that detect stimuli
–> In each organ are specialized sensory cells for detecting stimuli

Question 4

Specialized sensory cells

Answer 4

• Each sensory cell detects a particular kind of stimulus
• send signals to the brain through nerves to produce a sense

Question 5

How is sound produced

Answer 5

by the vibrations of objects

Question 6

frequency

Answer 6

no. of vibrations/second
→ unit: Hertz (Hz)
→ the faster an object vibrates, the higher the frequency

Question 7

How is sound transmitted

Answer 7

An object vibrates in the air, it pushes on the surrounding air particles
→ Causes them to vibrate
→ Vibrations of air particles travel through the air

Question 8

Sound must travel through

Answer 8

a medium (can be solid, liquid or gas)

Question 9

Why can’t sound travel through a vacuum

Answer 9

No particles to transmit sound

Question 10

process of sound travelling through our ears

Answer 10

pinna collects sound
–> ear canal
–> eardrum vibrate
–> three ear bones amplify vibrations of eardrum
–> sensory hair cells in the cochlea detect vibrations & produce signals
–> signals r sent to the brain through the auditory nerve
–> the brain interprets these signals as sound

Question 11

humans have an ________, 20Hz to 20000Hz

Answer 11

Audible frequency range

Question 12

Upper limit of hearing in a young person is ____ than an older person

Answer 12

higher

Question 12

Noise

Answer 12

any sound that is unwanted and disturbing

Question 13

how to Measure sound levels

Answer 13

decibel meter → unit: decibel (dB)

Question 14

Effect of noise on our health

Answer 14

• Extremely high sound levels or prolonged exposures to loud sound may result in tinnitus or even hearing loss
• Also cause other problems E.g. disturbing our study, work and sleep

Question 15

what does the Effect of noise depend on

Answer 15

sound level and the duration of exposure

Question 16

how to protect our sense of hearing

Answer 16

Keep the volume low when listening to music using headphones
Shorten the time you stay in a noise environment
If noise exposure is unavoidable, wear ear plugs or ear protectors
DO NOT pick your ears with hard object