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Flashcards in Problem 7 Deck (46)
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1

Physical definition of sound

Sound is pressure changes in the air

2

Perceptual definition of sound

Sound is the experience we have when we hear

3

Condensation

Causes an increase in the density of air molecules

--> increased air pressure

4

Rarefaction

Decreased density of air molecules

--> decreased air pressure

5

Pure tone

Occurs when changes in air pressure occur in a sine wave

--> fundamental building blocks of sound
--> rare in the environment

6

Frequency

The number of cycles per second that the pressure changes repeat

--> measured in hertz (Hz)

ex.: 1 Hz = 1 cycle/s

7

Amplitude

The size of the pressure change

--> difference in pressure between high + low peaks of the sound wave

(dB)

8

Complex tones

Consist of a number of pure tunes components added together

9

Harmonics

Refer to the components of complex tones

--> integer multiples of the fundamental

10

Fundamental/
First harmonic

The lowest frequency that is physically present in the sound

--> lowest tone of the harmonic series (longest WL)

11

Loudness

The perceptual quality, most closely related to amplitude, of an auditory stimulus

--> expressed in decibels
--> depends on amplitude + frequency

12

Audibility curve

Indicates the threshold for hearing vs frequency

13

Auditory response area

Area above the audibility curve

--> indicates where we can here sounds

14

Equal loudness curve

Indicates the sound levels that create the same perception of loudness at different frequencies

15

Pitch

The perceptual quality we describe as "high" or "low"

--> associated with music, speech + other natural sounds
--> can't be measured in a physical way, but measured by how we perceive it

=> our sense of pitch is limited to those frequencies that create phase locking

(<5.000 Hz)

16

Tone height

The perceptual experience of increasing pitch that accompanies increases in a tones fundamental frequency

17

Tone chroma

Notes with the same letter

18

Effect of the missing fundamental

Describes the constancy of pitch even when the fundamental or other harmonies are removed

19

Timbre

Describes the quality between 2 tones that have the same

a) loudness
b) pitch
c) duration

but still sound different

ex.: flute + oboes may play the same note but sound different

20

What influences the differences described in Timbre ?

a) attack
b) decay

21

Attack

The buildup of sound at the beginning of the tone

--> "fade-in" time

22

Decay

Decrease in sound at the end of the tone

--> "fade-out" time

23

Pinnae

Structures that stick out from the sides of the head

24

Outer ear

Consists of

a) pinnae
b) auditory canal

25

Auditory canal

Tubelike structure

--> protects the structures of the middle ear
--> enhances the intensities of some sounds

26

Middle ear

Small cavity that separates the outer + inner ears

--> contains the ossicles

27

Ossicles

3 smallest bones in the body, that make up the middle ear

a) malleus
b) incus
c) stapes

28

Tympanic membrane/
Eardrum

Located between the outer + middle ear

29

Middle Ear muscles

Smallest skelletal muscles that are attached to the ossicles

--> at very high sound levels they contract to dampen the ossicles vibration

ex.: contract so that sounds from chewing won't interfere with the perception of speech from other people

30

Cochlea

Snail like structure

--> main structure of the inner ear
--> performs fourier analysis (Tonotopy)