Hearing

Question 1

sound divides into three categories

Answer 1

1. loudness
2. pitch
3. timbre

Question 2

loudness

Answer 2

sound intensity/pressure measured close to the eardrum

factors influencing loudness - frequency content, duration, context in which it is presented

Question 3

pitch

Answer 3

crucial in communication

• perceptual correlate of waveform periodicity or repetition rate
• the faster a waveform repeats over time, the higher is its perceived pitch

Question 4

harmonic complex tones

Answer 4

most common pitch-evoking sounds

• complex bc more than one frequency
• harmonic bc frequencies are all integer multiples of a common fundamental frequency (FO)

ex: harmonic complex tone w a (FO) of 100Hz would also contain energy at frequencies of 200, 300, and 400 Hz

Question 5

overtone/harmonics

Answer 5

higher frequencies that determine pitch of a sound

Question 6

pitch of the missing fundamental

Answer 6

even if (FO) is absent, we generally still perceive the remaining sound to have a pitch corresponding to the (FO)

Question 7

modern grand piano

Answer 7

27.5 Hz to 4,186 Hz

Question 8

timbre

Answer 8

quality of sound

- bright, dull, hollow, harsh

Question 9

frequency of sound

Answer 9

high frequency = sounds brighter, tinnier, harsher

low frequency = sounds deeper, richer, dull

Question 10

quietest sound we can hear

Answer 10

1-4 Hz

Question 11

decibles

Answer 11

describes sound pressure/intensity

Question 12

masking

Answer 12

process by which the presence of a sound makes another sound more difficult to hear
ex: can’t hear phone ringing while in shower

Question 13

suppression

Answer 13

occurs when the response to the masker reduces the neural response to the target sound

• lower frequency sounds are more likely to mask higher frequencies
• “upward spread of masking”

Question 14

spatial hearing

Answer 14

360 degree field of hearing

Question 15

interaural time differences

Answer 15

ITD

• difference in time or intensity between two ears
• relies of fact that sound source on left will reach left ear before right ear
• largest occurs within a fraction of a millisecond

Question 16

interaural level differences

Answer 16

ILD

• at higher frequencies, the head casts an acoustic “shadow” so that when a sound is presented from the eft, the sound level at the left ear is somewhat higher than the sound level at the right ear
• as big as 20dB and as small as 1dB

Question 17

duplex theory

Answer 17

for everyday sounds as a broad frequency spectrum, it seems that our perception of spatial location is dominated by interaural time differences in low-frequency temporal fine structure

Question 18

auditory scene analysis

Answer 18

sounds that are in close proximity, in time or frequency, tend to be grouped together
- sounds that begin and end at the same time tend to form a single auditory object