phonetics janice fon graduate institute of linguistics national taiwan university
TRANSCRIPT
Phonetics
Janice Fon
Graduate Institute of Linguistics
National Taiwan University
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Overview
Speech sounds and phonetic transcription
Articulatory phonetics
Phonological categories and pronunciation variation
Acoustic phonetics and signals
Phonetic resources
Advanced: articulatory and gestural phonology
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Speech sounds and phonetic transcription (1)
PhoneticsThe study of speech sounds used in the languages of the world
PhoneA speech sound Represented with phonetic symbolsTwo types:
ConsonantsVowels
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Speech sounds and phonetic transcription (2)
Phonetic alphabetsIPA
Standard developed by International Phonetic Association
Alphabet + principles of transcription
ARPAbetDesigned for American English in ASCII symbols
Computer-friendly
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Speech sounds and phonetic transcription (3)
[ɹ]
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Speech sounds and phonetic transcription (4)
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Articulatory phonetics (1)
Definition:The study of how phones are produced
The vocal organ
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Articulatory phonetics (2)
Sounds are formed by the motion of air through the mouth
Consonants:Made by restricting or blocking the airflow in some way
May be voiced or voiceless
Vowels:Made with less obstruction
Usually voiced
Generally louder and longer than consonants
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Articulatory phonetics (3)
Consonants are defined by Place of articulation
The point of maximum constriction
Manner of articulationHow the restriction of airflow is made
Voicing State of the glottis
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Articulatory phonetics (4)
Place of articulation
coronal
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Articulatory phonetics (5)
LabialSounds whose main restriction is formed at the lips
Two subtypes:Bilabial: two lips
Labiodental: upper teeth + lower lip
Examples [國 ]: [p] 爸 , [pʰ] 怕 , [m] 媽 , [f] 法[閩 ]: [b] 肉 , [p] 爸 , [pʰ] 打 , [m] 媽[E]: [p] spy, [pʰ] pie, [m] my, [f] four, [v] very
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Articulatory phonetics (6)
DentalSounds made by placing the tongue against the teeth
Two subtypes:Dental: behind the teeth
Interdental: between the teeth
Examples [國 ]: [t ̪] 大 , [t ̪ʰ] 踏 , [s ̪] 撒 , [t ̪s ̪] 資 , [t ̪s ̪ʰ] 刺 , [n ̪] 那 , [l ̪] 辣 [閩 ]: [t ̪] 大 , [t ̪ʰ] 拖 , [s ̪] 沙 , [z ̪] 熱 , [t ̪s ̪] 十 , [t ̪s ̪ʰ] 柴 , [n ̪] 藍 , [l ̪] 賴 , [ɾ̪] 賊仔[E]: [θ] thing, [ð] the
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Articulatory phonetics (7)
AlveolarSounds made by placing the tongue against the alveolar ridge
Two subtypes:Alveolar: b/t teeth and alveolar ridge
Postalveolar/palato-alveolar: after the alveolar ridge
Examples [E]: [t] ten, [d] duck, [n] new, [s] sing, [z] zoo, [l] love, [ɹ] red, [ɾ] butter, [ʃ] she, [ʒ] garage, [tʃ] China, [dʒ] joy
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Articulatory phonetics (8)
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Articulatory phonetics (9)
PalatalSounds made by placing the tongue against the (hard) palate
Two subtypes:Prepalatal/alveolopalatal: the arc towards the roof of the mouth
Palatal: the roof of the mouth
Examples [國 ]: [ɕ] 削 , [tɕ] 交 , [tɕʰ] 敲 , [j] 妖[閩 ]: [ɕ] 是 , [tɕ] 摺 , [tɕʰ] 試 , [ʑ] 皺 , [j] 妖[E]: [j] yes
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Articulatory phonetics (10)
Velar Sounds made by placing the tongue against the velum/soft palate
Examples [國 ]: [k] 該 , [kʰ] 開 , [x] 害 , [ŋ] 忙[閩 ]: [k] 該 , [kʰ] 開 , [g] 牛 , [ŋ] 黃[E]: [k] ski, [kʰ] key, [g] good, [ŋ] sing
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Articulatory phonetics (11)
Glottal Sounds made at the glottis
Examples [國 ]: [ʔ] 唉[閩 ]: [h] 海 , [ʔ] 食[E]: [h] high, [ʔ] uh-oh
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Articulatory phonetics (12)
Retroflex Sounds made with the tongue tip curled back
Examples [國 ]: [ʂ] 扇 , [tʂ] 詹 , [tʂʰ] 蟬 , [ʐ] 然
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Articulatory phonetics (13)
Manner of articulationStop
Nasal
Fricative
Affricates
Approximant
Flap/tap
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Articulatory phonetics (14)
Stop = plosive Two phases:
Closure: airflow is completely blocked for a short timeRelease: an explosive sound as the air is released
Three types:Aspirated: closure + release + big puff of airUnaspirated: closure + release + small puff of airUnreleased stops: closure
Examples [國 ]: [p] 爸 , [pʰ] 怕 , [t ̪] 打 , [t ̪ʰ] 踏 , [k] 乾 , [kʰ] 看[閩 ]: [p] 爸 , [pʰ] 打 , [b] 肉 , [t ̪] 踏 , [t ̪ʰ] 桃 , [k] 菇 , [kʰ] 苦 , [g] 牛 , [p ̚] 十 , [t ̚] 結 , [k ̚] 角[E]: [p] spy, [pʰ] pie, [b] buy, [t] story, [tʰ] tie, [d] die, [k] sky, [kʰ] key, [g] guy
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Articulatory phonetics (15)
voiceless
voiced
spy pie
buy
鼻 皮
抹
narrow glottal opening wide glottal opening
to buy
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Articulatory phonetics (16)
Nasal
Made by lowering the velum and allowing air to pass into the nasal cavity
Examples [國 ]: [m] 媽 , [n ̪] 拿 , [ŋ] 紅[閩 ]: [m] 媽 , [n ̪] 貓 , [ŋ] 紅[E]: [m] my, [n] new, [ŋ] sing
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Articulatory phonetics (17)
Fricatives Process
Airflow is constricted but not cutoff completely
Turbulence is created
Two types
Sibilants: fricatives with high-pitched hissing noise
Nonsibilants: fricatives without high-pitched hissing noise
Examples
[國 ]: [f] 法 , [s ̪] 素 , [ʂ] 刪 , [ʐ] 然 , [ɕ] 先 , [x] 何[閩 ]: [s ̪] 素 , [z ̪] 熱 , [ɕ] 先 , [ʑ] 任 , [h] 何[E]: [f] few, [v] view, [θ] they, [ð] the, [s] sing, [z] zoo, [ʃ] she, [ʒ] garage, [h] high
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Articulatory phonetics (18)
Affricates
Homorganic stop + fricative
Examples [國 ]: [t ̪s̪] 租 , [t ̪s̪ʰ] 粗 , [tʂ] 朱 , [tʂʰ] 出 , [tɕ] 家 , [tɕʰ] 恰[閩 ]: [t ̪s̪] 租 , [t ̪s̪ʰ] 粗 , [tɕ] 一 , [tɕʰ] 七[E]: [f] few, [v] view, [θ] they, [ð] the, [s] sing, [z] zoo, [tʃ] choice, [dʒ] job
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Articulatory phonetics (19)
ApproximantTwo articulators are close together but not close enough to cause turbulent airflow
Two types:Approximant: air flows from the center of the tongue outward
Lateral approximant: air flows from the side(s) of the tongue outward
Examples [國 ]: [j] 牙 , [w] 娃 , [ɥ] 圓 , [l ̪] 來[閩 ]: [j] 厭 , [w] 歪 , [l ̪] 來[E]: [j] yes, [w] we, [l] like, [ɹ] read
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Articulatory phonetics (20)
Tap/flapA quick motion of the tongue against a hard surface
Examples [閩 ]: [ɾ̪] 賊仔 [E]: [ɾ] butter
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Articulatory phonetics (21)
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Articulatory phonetics (22)
Vowels are defined byTongue height
Tongue frontness/backness
Roundedness
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Articulatory phonetics (23)
意 欲 思 屋
矮 黑可
辦 棒
about
it
bet
bat
but bought
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Articulatory phonetics (24)
Three types of vowelsMonophthongs
A vowel in which the tongue position does not change
Diphthongs A vowel in which the tongue position changes once
= VG/GV
(ex) [國 ]: [aɪ] 埃 , [eɪ] 黑 , [aʊ] 好 , [oʊ] 候 , [ja] 牙 , [wa] 娃 , [ɥɛ] 約(ex) [閩 ]: [ju] 油(ex) [E]: [ɔɪ] boy
Triphthongs A vowel in which the tongue position changes twice
= GVG
(ex) [國 ]: [jaʊ] 妖 , [jaɪ] 崖 , [waɪ] 歪
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Articulatory phonetics (25)
SyllableConsonants and vowels combine to make a syllable
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Articulatory phonetics (26)
PhonotacticsConstraints on which phones can follow each other in a language
[國 ] CCVC: 片[閩 ] CCVC: 接 [E] CCCVCCC: strengths
[E] CCVCCCC: twelfths
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Articulatory phonetics (27)
Lexical stressA prominent syllable in a word that is determined by the lexicon
(ex) [國 ] 東西 [ˈtoŋɕi] vs. [ˈtoŋˈɕi]
Three levelsPrimary stress: dictionary
Secondary stress: dictionary
Unstressed: dictionary
In unstressed syllables, vowels can be Reduced: about [ə]
Unreduced: carry
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Articulatory phonetics (28)
Sentence stress= pitch accent
A prominent syllable in an utterance that is determined by pragmatics
(ex) 連站都站不好! 連戰都站不好!
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Phonological categories and pronunciation variation (1)
Pronunciations vary!
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Phonological categories and pronunciation variation (2)
Phoneme allophone/t/ [t, tʰ, ʔ, ʔt, ɾ, t ̚, t]̪
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Phonological categories and pronunciation variation (3)
(assimilation)
The degree of variation increases with more natural and colloquial speech
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Phonological categories and pronunciation variation (4)
Coarticulation The movement of articulators to anticipate the next sound or persevering movement from the last sound
(ex) nasalization, palatalization, voicing, etc.
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Phonological categories and pronunciation variation (5)
Distinctive features Binary variables which express some generalizations about groups of phonemes
Used to represent each phoneme as a matrix of feature values
Place features[labial], [coronal], [dorsal]
Manner features[consonantal], [vocalic], [continuant], [sonorant]
Voicing features[voice]
Vowel features[high], [low], [back], [round]
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Phonological categories and pronunciation variation (6)
Main use of featuresCapture natural articulatory classes of phones
Build articulatory feature detectors and use them to help phone detection
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Phonological categories and pronunciation variation (7)
Predicting phonetic variationPhonological rule
Caveat:Variation is a stochastic process
Many non-phonetic factors are important to this prediction task
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Phonological categories and pronunciation variation (8)
Factors influencing phonetic variationNon-phonetic
Speech rateWord frequencySpeaker’s state of mindMorphological boundariesSociolinguistic factors
Phonetic Intrinsic sound qualityProsodic boundariesCoarticulation
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Acoustic phonetics and signals (1)
Waves
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Acoustic phonetics and signals (2)
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Acoustic phonetics and signals (3)
For computers to record and manipulate speech, it is necessary to perform analog-to-digital conversion
A two-step processSampling—limit the number of places after the decimal point on the time axis
Quantization—limit the number of places after the decimal point on the amplitude axis
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Acoustic phonetics and signals (4)
Sampling rate
Number of sample taken per second
At least two samples per cycle
Nyquist frequencythe highest frequency component that can be captured with a given sampling rate
= ½ sampling rate
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Acoustic phonetics and signals (5)
Frequency = 100 HzSampling rate = 200 HzNyquist frequency = 100 Hz
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Acoustic phonetics and signals (6)
signal not in the original signal aliasing
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Acoustic phonetics and signals (7)
Quantization Analogous to measuring the amplitudes in the waveform with a ruler
The main issue is the accuracy of the amplitude measurements
The most popular choices for the number of bits used to encode speech samples are 8, 12, and 16 bits
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Acoustic phonetics and signals (8)
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Acoustic phonetics and signals (9)
Recording formatChannels: mono or stereo
Format: linear or compressed Linear: linear PCM
Compressed: -law log compression
Common format.wav, .aiff, .au
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Acoustic phonetics and signals (10)
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Acoustic phonetics and signals (11)
Fundamental frequency = F0
Measures speed of vocal fold vibration
Hertz
AmplitudeMeasures amount of air pressure variation
Pascal (Pa)
RMS
IntensitySound power per unit area measuring at a listener’s location
Decibels (dB)
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Acoustic phonetics and signals (12)
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Acoustic phonetics and signals (13)
Perceptual propertiesPitch
Mental sensation or perceptual correlate of F0
Mel scale
Loudness Perceptual correlated of power
Human ear has greater resolution in the low power range
Loudness interacts with frequency
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Acoustic phonetics and signals (14)
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Acoustic phonetics and signals (15)
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Acoustic phonetics and signals (16)
most sensitive
quick sensitivity drop
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Acoustic phonetics and signals (17)
1000 Hz 100 Hz
1x 2x 1x 2x
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Acoustic phonetics and signals (18)
Autocorrelation method
A pitch extraction algorithm that correlates the
signal with itself at various offsets
The offset that gives the highest correlation gives
the period of the signal
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Acoustic phonetics and signals (19)
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Acoustic phonetics and signals (20)
Interpreting phones from a waveform
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Acoustic phonetics and signals (21)
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Acoustic phonetics and signals (22)
FFT
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Acoustic phonetics and signals (23)
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Acoustic phonetics and signals (24)
The source-filter model
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Phonetic resources
Pronunciation dictionariesCELEX
CMUdict
PRONLEX
Phonetically annotated corpusEnglish: TIMIT, Switchboard, Buckeye
German: Kiel corpus
Japanese: CSJ
Mandarin: AS, NTU (Taiwan), CASS (China)
Phonetic softwardsPRAAT
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Advanced: articulatory and gestural phonology (1)
Articulatory phonology
Represents a speech utterance as a sequence of
potentially overlapping articulatory gestures
Advantages:
Gesture scores are likely to be much better hidden
states at capturing the continuous nature of speech than
a discrete sequence of phones
Help model the fine-grained effects of coarticulation of
neighboring gestures
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Advanced: articulatory and gestural phonology (2)