Audition

Question 1

Amplitude

Answer 1

variation in height of sound wave affects the perception of loudness
Greater amplitude = vibrations of higher intensity
Higher waves = louder sounds

Question 2

Loudness

Answer 2

• Measured in decibels

Loudness doubles for every 10dB increase

Question 3

Frequency of Sound Wave

Answer 3

affects perception of pitch
High Frequency: high pitched
Low Frequency: low pitched

Question 4

Purity

Answer 4

affects perception of timbre – complexity of a sound

Question 5

External Ear

Answer 5

pinna
ear canal
ear drum

Question 6

Pinna

Answer 6

folded cone that collects sound waves in the environment and directs them along ear canal

Question 7

Ear Canal

Answer 7

amplifies incoming sound waves

Question 8

Ear Drum

Answer 8

thin membrane vibrating at the frequency of incoming sound wave and forms back wall of ear canal

Question 9

Middle Ear

Answer 9

begins on other side of eardrum, between ear drum and oval window

Question 10

Ossicles

Answer 10

• consist of hammer, anvil, and stirrup
  
  • Amplify signals sent to oval window
    Additional amplification is necessary because changes in air pressure originally detected by the external ear are about to be converted to waves in the fluid filled inner ear

Question 11

Inner Ear

Answer 11

Cochlea
Oval Window
Basilar Membrane

Question 12

Cochlea

Answer 12

vibrating oval window connects here
- Fluid filled tube
Contains neural tissue necessary to transfer the changes in fluid to neural impulses of audition

Question 13

Oval Window

Answer 13

small opening in side of cochlea
- When vibrating it makes fluid in cochlea to become displaced
Bulges in and out to accommodate for movement of fluid

Question 14

Basilar Membrane

Answer 14

• Located inside cochlea
  
  • Higher frequency = nearest end to window openings to vibrate
    Lower frequency = end near apex to vibrate

Question 15

Auditory Receptors (Hair Cells)

Answer 15

• Inside basilar membrane

Hair cells move with membrane and this movement is converted to neural impulses the brain can understand

Question 16

Outer Hair Cells

Answer 16

• More numerous
  
  • Less connections to the brain
  • Slower
  • Function is to amplify the sound stimulus
    Axons are thin and unmyelinated

Question 17

Inner Hair Cells

Answer 17

• Less numerous
  
  • More connections to the brain
  • Faster
  • Establish exact pitch of sound stimuli
    Thick and myelinated

Question 18

Tonotopic Organization

Answer 18

• Hair cells connect to the cochlear nerve such that neighbouring regions of hair cells remain together
  Organization is maintained all the way through the auditory pathway to the primary auditory cortex

Question 19

Interaural Cues

Answer 19

• Difference in time it takes for the sound to reach each ear
  ○ Specific neurons in the superior olivary complex respond to these slight differences in timing
  
  • Detectable loss of intensity because the sound waves have to travel farther to one ear
    For distant sounds, ears rely on the difference in intensity caused by the sound shadow

Question 20

Pinna Cues

Answer 20

sound direction produced by the characteristic folds and ridges of pinnae
Some frequencies are amplified and others are attenuated

Question 21

Echolocation

Answer 21

process by which a receiver emits sound pulses and analyzes the returning echo to form a perceptual image of objects in the environment

Question 22

Co-evolution

Answer 22

process where evolution and adaptation of traits of one species can directly affect the evolution of traits in another species

Question 23

Why music evolved

Answer 23

1. Prosocial Behaviour: music promotes cooperative behaviour
   
   2. Intimidation: music allowed us to look bigger and more scary
      Courting Mechanism: someone who plays music is seen as more attractive

Question 24

amusia

Answer 24

an inability to discriminate pitch (tone deaf)

Question 25

Williams syndrome

Answer 25

severe mental deficits but increased music ability