Acoustic Phonetics

Front 1

Inverse square law

Back 1

propagated sound wave decreases 6 dB in amplitude (intensity) every doubling of distance

Front 2

White noise

Back 2

infinite # of frequencies make it up and all have the same average amplitudes

Front 3

When can pressure amplitudes be added?

Back 3

when they have the same frequency and starting phase

Front 4

When can intensity amplitudes be added?

Back 4

always

Front 6

Random Noise

Back 6

IDK but I think it could be on the test.

Front 7

Phoneme

Back 7

standard segmental unit

Front 8

Allophone

Back 8

subtle variation of the standard

Front 9

Syllable

Back 9

next largest unit after phoneme, consonant and vowel (nucleus) (250 msec average duration

Front 10

Average Rate of speech

Back 10

2-5 syllables per second

Front 11

Distinctive feature theory-

Back 11

way to compare and contrast between many different kinds of languages (ex degree of sonorites, attempt to blend production and perception)

Front 12

3 types of sound sources
1. Voiced sounds

Back 12

any sounds produced by opening and closing of vocal folds, periodic puffs of air (glottal pulses 120 for men, 200 for women, higher pulse rate=higher pitch)

Front 13

3 types of sound sources
2. turbulent sounds

Back 13

noisy sources, sound through a small constriction (fricatives)

Front 14

3 types of sound sources
3. transient source

Back 14

sudden burst, any time constriction is complete then released (plosives, stops), build up of sound behind a constriction

Front 15

Pressure

Back 15

force applied to an area
newtons/m^2
dynes/cm^2
pascal

Front 16

Intensity

Back 16

watts/m^2
watts/cm^2

Front 17

Wavelength

Back 17

distance traveled to complete one compression (cycle)
λ=c/f
c= speed of sound in a given medium
f= as freq increases, wavelength decreases
-inversely related
-high freq= short wavelength
-low freq= long wavelength

Front 18

Diffraction

Back 18

bending of sounds
-depends on wavelength and size of object in the path

Front 19

3 types of sound fields
1. Free field

Back 19

sound freely propagated (anechoic chamber is closest simulation of this)

Front 20

3 types of sound fields
2. reverberant field

Back 20

lots of reflected sound, very live acoustic field

Front 21

Types of sound field
3. diffuse field

Back 21

equal sound pressure everywhere in the room- like a frye box

Front 22

Sinusoid

Back 22

graph of a cyclical intensity, any measure of amplitude, has its own unique frequency, pure tone
*phase determines how different sinusoids add up

Front 23

Instantaneous amp

Back 23

amp at an instant in time

Front 24

rms

Back 24

root mean square, most common amplitude used
*square instantaneous amp, take mean of square values and then square root it
*on a sinusoid rms = .707x peak

Front 25

Waveform

Back 25

amplitude/time- can be used to describe any sound

Front 26

white noise

Back 26

infinite # of frequencies at the same average amplitude

Front 27

time domain

Back 27

waveform

Front 28

frequency domain

Back 28

amplitude spectrum

Front 29

Periodic sounds

Back 29

have discrete vertical lines on the amplitude spectrum, cyclical, repeats exactly

Front 30

Aperiodic

Back 30

Doesn't repeat, noise in real life is aperiodic, so are clicks, not made up of vertical lines on the amplitude spectrum

Front 31

non-linear

Back 31

introduces new frequencies

Front 32

linear

Back 32

input-> same frequency, can be different amplitude and phase.

Front 33

octave

Back 33

doubling of any frequency

Front 34

half octave formula

Back 34

freq X 2 ^1/2

Front 35

low pass filter

Back 35

passes low frequency,

Front 36

Lab filters

Back 36

can control the cutoff frequency, cannot control the attenuation rate. The only way to control the attenuation rate is by using more than 1 filter.

Front 37

resonance

Back 37

things vibrate at a specific frequency most easily

Front 38

Resonant filter

Back 38

found in nature, can amplify. Stimulus with input and respond with greater amplitude

Front 39

smaller the cavity of air...

Back 39

the higher the pitch

Front 40

1. If make length of vocal tract longer, formants all go down

Back 40

* inversely related
*Length of infants track 1/2 length, the formants are doubled
* women are 5/6 as long as adult male= formants go up 6/5

Front 41

2. location of constriction + degree constriction

Back 41

oral constriction/f1 rule- when constriction is up front, f1 goes lower (greater the degree, the lower it goes) (heed, hid, head)

Pharyngeal Constriction/f1 rule= back in vocal tract (area of pharynx constriction), then f1 goes higher (who, add)

Back tongue constriction/ f2 rule= f2 will go down when constriction is in the back of tract

Front tongue constriction/f2 rule= if constrict at front, f2 will go up

Front 42

Formant frequencies affects on vowels

Back 42

1. length of vocal tract
2. localization of constriction (tongue)
3. degree of constriction (narrow)

Front 43

3. lip rounding rule

Back 43

all formants go down when you round the lips

Front 44

source filter theory

Back 44

how to predict with a spectrum is going to look like at the output

Front 45

Specificity

Back 45

relative measure of how wide a curve is on a bandwidth filter

Front 46

bandwidth

Back 46

-3 dB from the top (Hilary's notes?)
how wide a band pass filter is between its upper and lower cutoff frequencies.

Band pass filters are also often discussed in terms of their center frequencies

Front 47

reverberation time

Back 47

time it takes to attenuate sound by 60 dB

Front 48

intermodulation

Back 48

summation and difference tones, occurs in non-linear system

Front 49

dipthong

Back 49

begins with a vowel and transitions to a different vowel

Front 50

diffuse

Back 50

equal pressure in the room, like a frye box

Front 51

if a signal is brief in time...

Back 51

it is broad in the frequency domain