Task 7

Question 1

Physical Aspects of Sound

- amplitude

Answer 1

• dB

- size of pressure change

Question 2

Physical Aspects of Sound

- frequency

Answer 2

• Hz

- number of cycles per second that pressure changes repeat

Question 3

Physical Aspects of Sound

• frequency
  
  • fundamental frequency

Answer 3

• fundamental frequency = repitition rate

Question 4

Physical Aspects of Sound

• frequency
  
  • harmonics

Answer 4

• harmonic of a tone = each component

Question 5

Physical Aspects of Sound

• frequency
  
  • Fourier analysis

Answer 5

• decomposing complex sounds in their specific frequencies

Question 6

Perceptual Aspects of Sound

- loudness

Answer 6

• perceptual quality
• dB
• most closely related to the level or amplitude of an auditory stimulus

Question 7

Perceptual Aspects of Sound

- pitch

Answer 7

= perceptual quality described as ‘high’ or ‘low’

- missing fundamental = pitch remains the same, even when fundamental or other harmonics are removed

Question 8

Perceptual Aspects of Sound

- timbre

Answer 8

= quality that distinguishes between two tones that have the same loudness, pitch, and duration, but still sound different

Question 9

relation dB, loudness & sound pressure

Answer 9

dB = 20 log(p/po)

Question 10

The outer ear

- pinnae

Answer 10

• structure that sticks out of head

- location of sounds, catches sound waves

Question 11

The outer ear

- auditory canal

Answer 11

• protection of tympanic membrane (eardrum) and helps keep this membrane and the structures i the middle ear at a relatively constant temperature
• enhances intensities of some sounds by means of physical principle of resonance

Question 12

The middle ear

- ossicles

Answer 12

• three smallest bones in the body
• malleus (hammer), incus (anvil) and stapes
• increase pressure factor
• concentrate vibration of large tympanic membrane onto the much smaller stapes

Question 13

The inner ear

• Cochlea
  
  • tonotopy

Answer 13

• cochlea: snaillike structure
• tonotopy:
  
  • mapping
  • parts of the cochlea responsive to the different frequencies

Question 14

The inner ear

• Cochlea
  
  • Organ of Corti

Answer 14

• on basilar membrane

Question 15

The inner ear

• Cochlea
  
  • Organ of Corti
    
    • Hair Cells

Answer 15

• hair cells: receptors for hearing
• one row inner hair cells
• three rows outer hair cells
• movement to the right: increase in pressure
• movement to the left: decrease in pressure

Question 16

The inner ear

- Transduction

Answer 16

movement of hair cells —> transmitter release —> action potentials

Question 17

The inner ear

- process when hair cells move

Answer 17

hair cells move —> tectorial membrane sliding back and forth —> up and down motion of basilar membrane

Question 18

The inner ear

- phase locking

Answer 18

• auditory nerve fibers in synchrony with rising an falling pressure of pure tone

Question 19

Pathway to the brain

Answer 19

Cochlea —> SONIC MG —> Auditory Cortex (A1)

• SON: superior olivary nucleus
• IC: inferior colliculus
• MG: medial geniculate nucleus
• from A1: to core or belt area

Question 20

Coding of Frequency

- place code

Answer 20

• tonotopy

Question 21

Coding of Frequency

- time code

Answer 21

• phase locking of auditory nerve/neural responses to the stimulus
• phase locking of responses of a group of auditory nerves/neurons (‘volley principle’)

Question 22

Deafness and Hearing Aids

- conductive hearing loss

Answer 22

• outer/middle ear

- amplification of sounds

Question 23

Deafness and Hearing Aids

- sensorineural hearing loss

Answer 23

• hair cells / auditory nerves

- cochlear implant; auditory brain stem implant

Question 24

Deafness and Hearing Aids

- hidden hearing loss

Answer 24

• people with “normal” hearing who have trouble hearing in noisy environments
• damaged auditory nerve fibers