语言学——发音英文版

Phonetics: Distinctive Phonetic Features* Feature Description _ Consonantal produced with a constriction along center line of oral cavity. Only vowels, /w/, /h/, and /y/ are not. Vocalic Anterior Coronal Continuant Strident largely unobstructed vocal tract. Vowels and liquids (/l/, /r/) are vocalic; glides (/w/, /y/) are not. point of articulation near alveolar ridge, including all labial and dental sounds. articulation involves front of tongue no complete obstruction in oral cavity; only nasals, stops, and affricates are non-continuant articulation with long, narrow constriction; such as /s/, /z/, /f/, /v/, /sh/, /zh/, /ch/, /jh/
− Pickett, The Acoustics of Speech Communication, p. 7.
Phonemes indicated by / /; phones (allophones) indicated by [ ].
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Phonetics: Introduction Syllable: • Unit of speech containing one or more phonemes. • A vowel in a syllable is called the syllable nucleus. • Most syllables contain one vowel (or diphthong); some contain only a lateral (“bott/le”) or nasal (“butt/on”) as the most intense sound. • Syllable boundaries sometimes ambiguous (“tas/ty” vs. “tast/y” vs. “ta/sty”) Coarticulation: The “blending” of two or more adjacent phones, causing a non-distinct boundary between them. Coarticulation is caused by smooth changes in the articulators (lips, tongue, jaw) over time.
• One assumption of phonology: utterances can be represented as sequence of discrete units.
• Are such units purely an “invention” of linguistics? Spoonerisms (“belly jeans” vs. “jelly beans”) and rhymes indicate small units of language (Reverend William Archibald Spooner (1844-1930)) • Utterances of the same word(s) have many differences… we’re usually only interested in those differences that are “linguistically significant” or that are “perceived as different”. • Implies a somewhat subjective nature to phonology, whereas we want an objective measure of perceived or produced units.
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Phonetics: Distinctive Phonetic Features
nasal tract velic port velum (soft palate) tongue pharynx glottis
(vocal folds and space between vocal cords)
(hard) palate oral tract alveolar ridge lips teeth tongue tip larynx (voice box)
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vocal folds = vocal cords
The Speech Production Apparatus (from Olive, p. 23)
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Phonetics: Introduction Coarticulation Example:
y
uw
aa
r
“you are”: /y uw aa r/
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Phonetics: Introduction Another Example of Coarticulation:
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Phonetics: Introduction (adapted from Schane, p. 4-6) • Speech signal is continuous; we perceive discrete entities. (How many sound units are in the word “cat”?)
CS 551/652: Structure of Spoken Language Lecture 2: Spectrogram Reading and Introductory Phonetics
John-Paul Hosom Fall 2010
Spectrogram Reading Why bother??
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More Formant Data…
(source unknown)
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Phonetics: Introduction Phonology: A description of the systems and patterns of sounds that occur in a language (abstract), often involving comparisons between languages and/or evolution of a language over time. Phonetics: A branch of phonology that deals with individual speech sounds, their production, and their written representation. Phoneme: • A unit of speech that can be used to differentiate words (e.g. “cat” /k ae t/ vs. “bat” /b ae t/). • Phonemes identify minimal pairs in a language. • The set of phonemes in a language subject to interpretation; most languages have 20 to 40 phonemes.
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Phonetics: Introduction Allophone: A speech sound constituting one of the systematic phonetic variants of a given phoneme. Different allophones are predictable from environment (e.g. “toe”, “caught”, “fitness”, “writer”; “sill”, “still”, “spill”) Phone: An acoustic realization of a phoneme. (Many different phoFra Baidu bibliotekes may represent the same phoneme.) “The phoneme /s/ consists of more than 100 allophones”
• Features may be binary or multi-valued
• Capital letters indicate feature name: Manner square brackets [] indicate feature value: [+fricative]
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Phonetics: Distinctive Phonetic Features • Exact set of features and feature values depends on goals (no “right” or “wrong” set of features or values) • Distinctive features provide a vocabulary for describing speech • Are distinctive features purely an “invention” of linguistics? memory tasks show that when people forget a phoneme, they usually remember a phoneme with similar distinctive features
What’s the point of spectrogram reading? Do people read spectrograms as part of their job? Do computers “read” spectrograms in order to recognize speech? There are some jobs that require spectrogram reading (e.g. phonetic time alignment), but not many. Automatic speech recognition systems do not process speech in this way.
Primary reason for spectrogram reading: If you’re going to work on a problem, it’s advisable to understand the nature of that problem. Spectrogram reading provides a direct method for “hands-on” learning of the characteristics of speech. Studying phonetics, signal processing, or techniques in speech recognition/speech synthesis does not fully convey the complexity and structure of spoken language.
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Phonetics: Distinctive Phonetic Features • Phonemes do not differ randomly from one another; there are relationships among phonemes (e.g. /p/ vs. /t/ vs. /ah/) • A (distinctive) feature is a “phonetic property that can be used to classify sounds” [Ladefoged, p. 42] • Typically, features are associated with aspects of articulation