hearing part 1

Question 1

what is sound

Answer 1

pressure changes in air or another medium

caused by vibrating objects such as vocal cord, speaker diaphragm, car engine, fan

Question 2

condensation

Answer 2

air molecules pushed together

- caused by vibrating objects

Question 3

rarefaction

Answer 3

air molecules are spread out

- caused by vibrating objects

Question 4

speed of sound in air

Answer 4

343.2 m/s
1,236 km/h
768mph
travels 1 km in 2.9s and 1m in 4.7

Question 5

what is a pure tone

Answer 5

generated by tuning fork or computer

osculations are regular

Question 6

3 ways to describe pure tones

Answer 6

sine wave- sinosoidal change in air pressure
frequency- number of cycles per second
amplitude- size of pressure change

Question 7

unit for measuring sound frequency

Answer 7

cycles per second

Hertz = Hz

Question 8

unit for amplitude

Answer 8

magnitude of air pressure changes

decibels = dB

Question 9

what is the quitest sound we can hear

Answer 9

defined as 0 decibels with 1 amplitude

Question 10

complex tones

Answer 10

made by combining pure tones

contain a mix of different frequencies in them

Question 11

harmonics

Answer 11

periodic tones that repeat regularly

Question 12

fundamental frequency

Answer 12

the repetition rate of a harmonic

- second harmonic is 2x fundamental frequency

Question 13

spectrogram

Answer 13

frequency vs time
represents amount of energy at each level
color indicates amplitude
ex. ramp down, ramp up

Question 14

speech

Answer 14

made up of very complex sound

in the middle range of what we are most sensitive to hear

Question 15

how do we perceive loudness

Answer 15

perceptual quality most closely related to level or amplitude of an auditory stimulus
- linear relationship between decibels and percevied loudness

Question 16

audibility curve

Answer 16

loudness varies with frequency

dB vs Hz

Question 17

what range to humans here

Answer 17

20 Hz- 20,000 Hz

8 dB- 140 dB

Question 18

pitch

Answer 18

perceptual quality we describe as high and low

pitch is related to (not equal) fundamental frequency

Question 19

tone heigh

Answer 19

generally goes up with fundamental frequency

as you go up the paino each tone sounds “higher”

Question 20

tone chroma

Answer 20

notes whose fundamentals are multiple of two have the same chroma
ex. As on a keyboard
sound similar to us

Question 21

what happens when youre missing fundamental

Answer 21

it does not change the pitch

sounds almost identical

Question 22

timbre

Answer 22

related to number and strength of harmonics
have same fundamental frequency but different energy at different harmonics
have the same loudness and pitch but sound different

Question 23

shepard- risset glissando

Answer 23

auditory illusion that appears to be going down continuously

Question 24

constant spectrum melody

Answer 24

spectrum does not change over time