10.3 Hearing + 10.7 Brain Flashcards
What is sound produced by
Vibrations of objects
Whats frequency
Unit
Vibrations made per second
Hertz
Relationship between tuning fork length and frequency
Shorter prong higher frequency
越短越快越高音
how is sound transmitted
- Object vibrates
- Push on surrounding air particles
- Particles vibrate, travel through air
Sound must travel through a ____, it can be a _____, ______, _____
Medium
Solid liquid gas
Sound is transmitted through __________ in these medias
Vibrations of particles
Why can’t sound travel through vacuum
No air, no particles transmit sound, no sound can be heard
Speed of sound in diff media
Fastest in solids
Slowest in gases
Why cant sound be heard in space
Space is a vacuum, sound cant travel through it
Ear structure
Pinna, ear canal, ear drum, ear bones, cochlea, auditory nerve
How we hear
- Pinna collects sound, directs into ear canal
- Travels down ear canal to middle ear
- sound causes eardrum vibrate, vibrations transmitted to ear bones
- 3 ear bones amplify eardrum’s vibrations, transmit to inner ear
- Sensory hair cells in cochlea detect vibrations, produce signals
- Signals fr sensory hair cells sent to brain through auditory nerve , interprets signals as sounds
Why cant hear clearly
What helps them hear better
Ear bones / sensory hair cells in cochlea not function properly
hearing aid / cochlea implant
Limitation
Audible frequency range; only hear within certain range of frequency, 20-20000 Hz
Whats noise, sources, cause
Unwanted, disturbing
Traffic, construction work, Humm a voices, loud music
Noise pollution
Measure sound level
Unit
Decimal meter
dB
Effects of noise depends on
Cause
Daily life problems
Sound level, duration of exposure
Extremely high sound levels / prolonged exposure to loud sound
Tinnitus, hearing loss
Disturb study work sleep, mental stress
Protect hearing
Low volume
Shorten time, noisy environment
Ear plugs, protectors
X. Pick w hard obj
Sense organs ___________ and _________ to brain to produce ________. Brain uses signals from sense organs to help us _________.
Detect stimuli
Sends signals
Senses
Respond to stimuli
Role of brain
Sense organs cant produce senses, they’re detect stimuli and sends signals to brain.
Brains acts as coordinator
How brain makes response
- Integrates and interprets signals
- Produce sense
- Decide action
- Signal muscle through nerves
- Make response
Whats reaction time
Time between detecting a stimulus and making response
How many nerve cells does brain hv
How signals sent fr cell to cell
10B +
Long extensions
Parts of brain, functions
Cerebrum:
1. Inter grants, interprets signals
2. Signals muscle to make response
3. Intelligence, memory, thinking
Cerebellum:
1. Coordinates muscles, movements
2. Maintain body balance
Medulla:
1. Basic life functions, heartbeat, breathing, blood pressure
What causes illusions
Brain interprets signals incorrectly
