hearing (audition)

Question 1

what is sound?

Answer 1

• pressure wave in air
• sound waves (like all waves) vary in amplitude and frequency)
• period = 1/frequency
• frequency: the number of times per second a sound wave goes from high pressure to low pressure

Question 2

loudness and pitch

Answer 2

• loudness (intensity) if a sound corresponds to its amplitude
• high amplitude = loud
• pitch of a sound corresponds to its frequency
• high frequency = high pitch

Question 3

structure of the ear

Answer 3

• flashy flap at the side of the head is called a pinna (or pinnae) and is not really the ear

Question 4

hearing

Answer 4

• sound waves enter the ear canal
• causes tympanic membrane (eardrum) to vibrate
• causes the ossicles (malleus, incus, and stapes) to move the basilar membrane (inside the cochlea) up and down
• basilar membrane movement causes hair cells to fire nerve impulses along the auditory nerve which get sent to the brain for processing

Question 5

hearing

Answer 5

• sound waves enter the ear canal
• causes tympanic membrane (eardrum) to vibrate
• causes the ossicles (malleus, incus, and stapes) to move the basilar membrane (inside the cochlea) up and down
• basilar membrane movement causes hair cells to fire nerve impulses along the auditory nerve which get sent to the brain for processing

Question 6

sound processing

Answer 6

• a lot of processing of sound is a consequence of the mechanical properties of the basilar membrane and activation of hair cells along its surface
  sound enters pinna - tympanic membrane converts sound to vibration