Transcript Phonetics - Uttaradit Rajabhat University
Phonetics
Janice Fon Graduate Institute of Linguistics National Taiwan University
Overview Speech sounds and phonetic transcription Articulatory phonetics Phonological categories and pronunciation variation Acoustic phonetics and signals Phonetic resources Advanced: articulatory and gestural
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Speech sounds and phonetic transcription (1) Phonetics The study of speech sounds languages of the world used in the Phone A speech sound Represented with phonetic symbols Two types: Consonants Vowels 3
Speech sounds and phonetic transcription (2) Phonetic alphabets IPA Standard developed by International Phonetic Association Alphabet + principles of transcription ARPAbet Designed for American English in ASCII symbols Computer-friendly 4
Speech sounds and phonetic transcription (3) [ ɹ] 5
Speech sounds and phonetic transcription (4) 6
Articulatory phonetics (1) Definition: The study of how phones are produced The vocal organ 7
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 8
Articulatory phonetics (3) Consonants are defined by Place of articulation The point of maximum constriction Manner of articulation How the restriction of airflow is made Voicing State of the glottis 9
Articulatory phonetics (4) Place of articulation coronal 10
Articulatory phonetics (5) Labial Sounds whose main restriction is formed at the lips Two subtypes: Bilabial: two lips Labiodental: upper teeth + lower lip Examples [ 國 ]: [p] 爸 , [p ʰ] 怕 , [m] 媽 , [f] 法 [ 閩 ]: [b] 肉 , [p] 爸 , [p ʰ] 打 , [m] 媽 [E]: [p]
s p y
, [p ʰ]
p ie
, [m]
m y
, [f]
f our
, [v]
v ery
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Articulatory phonetics (6) Dental Sounds 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 ̪s̪] 資 , [t ̪s̪ʰ] 刺 , [n ̪] 那 , [l ̪] 辣 [ 閩 ]: [t ̪] 大 , [t ̪ʰ] 拖 , [s ̪] 沙 , [z ̪] 熱 , [t ̪s̪] 十 , [t ̪s̪ʰ] 賴 , [ ɾ̪] 賊仔 柴 , [n ̪] 藍 , [l ̪] [E]: [θ]
th ing
, [ð]
th e
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Articulatory phonetics (7) Alveolar Sounds 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]
t en
, [d]
d uck
, [n]
n ew
, [s]
s ing
, [z]
z oo
, [l]
l ove
, [ ɹ]
r ed
, [ ɾ]
bu tt er
, [ ʃ]
sh e
, [ ʒ]
gara ge
, [t ʃ]
Ch ina
, [d ʒ]
j oy
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Articulatory phonetics (8) 14
Articulatory phonetics (9) Palatal Sounds 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 , [t ɕ] 交 , [t ɕʰ] 敲 , [j] 妖 [ 閩 ]: [ ɕ] 是 , [t ɕ] 摺 , [t ɕʰ] 試 , [ ʑ] 皺 , [j] 妖 [E]: [j]
y es
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Articulatory phonetics (10) Velar Sounds made by placing the tongue against the velum/soft palate Examples [ 國 ]: [k] 該 , [k ʰ] 開 , [x] 害 , [ŋ] 忙 [ 閩 ]: [k] 該 , [k ʰ] 開 , [g] 牛 , [ŋ] 黃 [E]: [k]
s k i
, [k ʰ]
k ey
, [g]
g ood
, [ŋ]
si ng
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Articulatory phonetics (11) Glottal Sounds made at the glottis Examples [ 國 ]: [ ʔ] 唉 [ 閩 ]: [h] 海 , [ ʔ] 食 [E]: [h]
h igh
, [ ʔ]
uh oh
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Articulatory phonetics (12) Retroflex Sounds made with the tongue tip curled back Examples [ 國 ]: [ ʂ] 扇 , [t ʂ] 詹 , [t ʂʰ] 蟬 , [ ʐ] 然 18
Articulatory phonetics (13) Manner of articulation Stop Nasal Fricative Affricates Approximant Flap/tap 19
Articulatory phonetics (14) Stop = plosive Two phases: Closure: airflow is completely blocked for a short time Release: an explosive sound as the air is released Three types: Aspirated: closure + release + big puff of air Unaspirated: closure + release + small puff of air Unreleased stops: closure Examples [ 國 ]: [p] 爸 , [p ʰ] 怕 , [t ] 打 , [t ʰ] 踏 , [k] 乾 , [k ʰ] 看 [ 閩 ]: [p] 爸 , [p ʰ] 打 , [b] 肉 , [t ] 踏 , [t ʰ] 桃 , [k] 菇 , [k ʰ] 苦 , [g] 牛 , [p ̚] 十 , [t ̚] 結 , [k ̚] 角 [E]: [p]
s p y
, [p ʰ]
p ie
, [b]
b uy
, [t]
s t ory
, [t ʰ]
t ie
, [d]
d ie
, [k]
s k y
, [k ʰ]
k ey
, [g]
g uy
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Articulatory phonetics (15) narrow glottal opening wide glottal opening voiceless spy 鼻 pie 皮 voiced buy to buy 抹 21
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]
m y
, [n]
n ew
, [ŋ]
si ng
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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]
f ew
, [v]
v iew
, [θ]
th ey
, [ð]
th e
, [s]
s ing
, [z]
z oo
, [ ʃ]
sh e
, [ ʒ]
gara ge
, [h]
h igh
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Articulatory phonetics (18) Affricates Homorganic stop + fricative Examples [ 國 ]: [t ̪s̪] 租 , [t ̪s̪ ʰ ] 粗 , [t ʂ] 朱 , [t ʂ ʰ ] 出 , [t ɕ] 家 , [t ɕ ʰ ] 恰 [ 閩 ]: [t ̪s̪] 租 , [t ̪s̪ ʰ ] 粗 , [t ɕ] 一 , [t ɕ ʰ ] 七 [E]: [f]
f ew
, [v]
v iew
, [θ]
th ey
, [ð]
th e
, [s]
s ing
, [z]
z oo
, [t ʃ]
ch oice
, [d ʒ]
j ob
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Articulatory phonetics (19) Approximant Two 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]
y es
, [w]
w e
, [l]
l ike
, [ ɹ]
r ead
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Articulatory phonetics (20) Tap/flap A quick motion of the tongue against a hard surface Examples [ 閩 ]: [ ɾ̪] 賊仔 [E]: [ ɾ]
bu tt er
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Articulatory phonetics (21) 27
Articulatory phonetics (22) Vowels are defined by Tongue height Tongue frontness/backness Roundedness 28
Articulatory phonetics (23) 意 欲 矮
it
思
bet bat
辦 屋 可
about but
黑
bought
棒 29
Articulatory phonetics (24) Three types of vowels Monophthongs A vowel in which the tongue position does not change Diphthongs A vowel in which the tongue position changes once = VG/GV (ex) [ 國 ]: [a ɪ] 埃 , [e ɪ] 黑 , [a ʊ] 好 , [o ʊ] 候 , [ja] 牙 , [wa] 娃 , [ ɥɛ] 約 (ex) [ 閩 ]: [ju] 油 (ex) [E]: [ ɔɪ]
b oy
Triphthongs A vowel in which the tongue position changes twice = GVG (ex) [ 國 ]: [ja ʊ] 妖 , [ja ɪ] 崖 , [wa ɪ] 歪 30
Articulatory phonetics (25) Syllable Consonants and vowels combine to make a syllable 31
Articulatory phonetics (26) Phonotactics Constraints 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 stress A prominent syllable in a word that is determined by the lexicon (ex) [ 國 ] 東西 [ ˈtoŋɕi]
vs.
[ ˈtoŋˈɕi] Three levels Primary stress:
dic tionary
Secondary stress:
diction a ry
Unstressed:
dic tion a ry
In unstressed syllables, vowels can be Reduced:
a bout
[ ə] Unreduced:
carr y
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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！ 34
Phonological categories and pronunciation variation (1) Pronunciations vary!
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Phonological categories and pronunciation variation (2) Phoneme /t/ allophone [t, t ʰ, ʔ, ʔt, ɾ, t ̚, t̪] 36
Phonological categories and pronunciation variation (3) The degree of variation increases with more natural and colloquial speech (assimilation) 37
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. 38
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] 39
Phonological categories and pronunciation variation (6) Main use of features Capture natural articulatory classes of phones Build articulatory feature detectors and use them to help phone detection 40
Phonological categories and pronunciation variation (7) Predicting phonetic variation Phonological rule Caveat: Variation is a stochastic process Many non-phonetic factors are important to this prediction task 41
Phonological categories and pronunciation variation (8) Factors influencing phonetic variation Non-phonetic Speech rate Word frequency Speaker’s state of mind Morphological boundaries Sociolinguistic factors Phonetic Intrinsic sound quality Prosodic boundaries Coarticulation 42
Acoustic phonetics and signals (1) Waves 43
Acoustic phonetics and signals (2) 44
Acoustic phonetics and signals (3) For computers to record and manipulate speech, it is necessary to perform analog-to digital conversion A two-step process Sampling — 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 45
Acoustic phonetics and signals (4) Sampling rate Number of sample taken per second At least two samples per cycle Nyquist frequency the highest frequency component that can be captured with a given sampling rate = ½ sampling rate 46
Acoustic phonetics and signals (5) Frequency = 100 Hz Sampling rate = 200 Hz Nyquist frequency = 100 Hz 47
Acoustic phonetics and signals (6) signal not in the original signal aliasing 48
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 49
Acoustic phonetics and signals (8) 50
Acoustic phonetics and signals (9) Recording format Channels: 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) 52
Acoustic phonetics and signals (11) Fundamental frequency = F 0 Measures speed of vocal fold vibration Hertz Amplitude Measures amount of air pressure variation Pascal (Pa) RMS Intensity Sound power per unit area measuring at a listener’s location Decibels (dB) 53
Acoustic phonetics and signals (12) 54
Acoustic phonetics and signals (13) Perceptual properties Pitch Mental sensation or perceptual correlate of F 0 Mel scale Loudness Perceptual correlated of power Human ear has greater resolution in the low power range Loudness interacts with frequency 55
Acoustic phonetics and signals (14) 56
Acoustic phonetics and signals (15) 57
Acoustic phonetics and signals (16) quick sensitivity drop most sensitive 58
Acoustic phonetics and signals (17) 1x 2x 1000 Hz 1x 2x 100 Hz 59
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 60
Acoustic phonetics and signals (19) 61
Acoustic phonetics and signals (20) Interpreting phones from a waveform 62
Acoustic phonetics and signals (21) 63
Acoustic phonetics and signals (22) FFT 64
Acoustic phonetics and signals (23) 65
Acoustic phonetics and signals (24) The source-filter model 66
Phonetic resources Pronunciation dictionaries CELEX CMUdict PRONLEX Phonetically annotated corpus English: TIMIT, Switchboard, Buckeye German: Kiel corpus Japanese: CSJ Mandarin: AS, NTU (Taiwan), CASS (China) Phonetic softwards PRAAT 67
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 68
Advanced: articulatory and gestural phonology (2) 69