Harvard Linguistics 110 - Class 05 Ipa + Lab Phonetics

Linguistics 110 Class 5 (10/2/02)

Zhang/Öztürk/Quinn

The International Phonetic Alphabet (IPA) (0) Homework: Fromkin p.480—11.1, 11.2; p.485—11.5; p.492—11.7, 11.8, 11.9; p.514—11.16. Due 10/7 (Mon) in class. (0)’ • Section classroom move: Boylston 104 → Boylston 103 • Need volunteers to go to the Robinson 107 section. (1) Spelling and speech: •

Did he believe that Caesar could see the people seize the seas? The silly amoeba stole the key to the machine.

•

though, tough, bought, cough, through, bough George Bernard Shaw’s joke about ghoti.

•

A combination of letters may represent a single sound: shoot character Thomas physics either deal rough nation coat glacial theater plain

•

Some letters have no sound in certain words: mnemonic whole resign ghost pterodactyl write hole could psychology sword debt gnaw bough lamb island knot

•

We are concerned with pronunciation, not orthography! We need a system for writing the pronunciation—transcription. —IPA (International Phonetic Alphabet)

(2) Purposes of IPA: • show pronunciation in a dictionary; • record a language in linguistic fieldwork; • form the basis of a writing system for a language. (3) Principles of IPA: • a set of symbols for representing all the possible distinctive sounds in the world’s languages; (about 90 consonants and 26 vowels) • one symbol ⇔ one sound; • use ordinary Roman letters as much as possible; • use of diacritics for suprasegmentals, minute shades of a sound. → economy of the system

1

(4) Some IPA symbols for non-English sounds •

Stops:

p’, t’, k’ (ejectives) ∫, Î, ƒ (implosives)

•

Trills:

ı, R

•

Clicks:

>, ˘, <, ¯, ≤

•

Vowels:

y, P, {, ¨, Ø

(5) Some useful IPA diacritics • • • •

aspirated nasalized long voiceless

Ó ) … 9

• • • •

unreleased rhoticity dental syllabic

} ± 1 `

noise in the glottis, especially at end of consonant ([pÓ]) air flows through nose as well as through mouth ([a)]) longer duration ([a…]) partial or no vocal cord vibration in an otherwise voiced sound ([l9]) release of consonant as mouth opens not heard ([d}]) r-coloring ([„]) upper teeth used as passive articulator ([d1]) a syllable without a vowel ([®`]).

(6) Suprasegmentals and how they are marked in IPA •

Stress: "permit "pervert "subject "content

per"mit per"vert sub"ject con"tent

ÆAppa"lachian, ÆMissi"ssippi, ob"streperous, ÆonoÆmato"poetically •

•

Tone: Mandarin:

ßoUâ ßoUü ßoUÄ ßoUë

‘to collect’ ‘ripe’ ‘hand’ ‘thin’

Intonation: Ã That’s a cat.

ã That’s a cat?

a. ‘Who’s over there?’ ‘Laura.’ b. Question = ‘Did you say Laura?’ c. Calling Laura’s name when she’s far away. d. Reprimand: ‘How could you have done that?’

2

Laboratory Studies of Phonetics ARTICULATORY INFORMATION FROM THE LAB (7) Static Palatography: •

Purpose: to study the region of upper surface of vocal tract or tongue contacted for a certain speech sound.

•

Method: paint palate OR tongue with mixture of charcoal and olive oil. When tongue touches palate, the coated surface transfers coating to the other surface.

•

Palatogram: paint tongue, data from palate. Need mirror.

•

Linguogram: paint palate, data from tongue.

•

Any precautions? a. If you are interested in the difference in place of articulation between [s] and [S] in English, should you use sop-shop or sot-shot? b. Anything about the vowel contexts?

(8) Dynamic Palatography—Electropalatography (EPG) • • • • •

Subject wears a custom-made pseudo-palate that has electrodes embedded in its surface. When an electrode is contacted, a circuit is completed, current flows, and the contact is recorded. The information is sampled over time (typically 40-200Hz, i.e., every 25-5 msecs) Advantages over static palatography: quantitative, time-varying information. Disadvantages: expensive (around $1,300 per speaker), pseudo palate might alter speech.

(9) Electromagnetic Articulography (EMA) •

Purpose: to track articulator movements over time during speech production using alternating electromagnetic fields.

•

Physical principle the device is based on: the electromagnetic field strength in a receiver is inversely proportional to the cube of its distance from a transmitter.

•

Method: a. Three transmitter coils placed equidistant from one another so that they generate a radially symmetric alternating electromagnetic field at different frequencies. b. A number of receiver coils (sensors) placed on the subject’s articulators (tongue, jaw, lips and teeth) along the midsagittal plane. c. The induced voltages on receiver coils are sampled at a high frequency. d. These voltages provide a measure of each receiver’s distance from each transmitter.

3

e. The Cartesian coordinates of each receiver can be calculated as the point where the radii of three circles from the three transmitters intersect. (10) • • • (11)

Other means of studying the vocal tract: X-ray. Ultrasound. Magnetic Resonance Imaging (MRI). Articulatory study of the larynx.

•

Fiberscopic laryngoscope.

•

Electroglottography (EGG). a. Purpose: to study vocal fold behavior such as f0, closed and open quotients, non-invasive. b. Method: place a set of skin electrodes on both sides of the larynx; glottis open → increased impedance; glottis closed → decreased impedance.

AERODYNAMIC INFORMATION FROM THE LAB (12)

Using flow masks to collect aerodynamic data:

•

Purpose: to study timing, magnitude or aspiration, nasalization, frication, etc. To infer articulatory information when such information is hard to collect (e.g., movement of velum).

•

Method: flow masks (separate masks for oral and nasal, or one mask with split channels). A pressure transducer translates pressure to electrical volt.

ACOUSTIC INFORMATION FROM THE LAB (13) • •

(14) • •

Source and filter: Source: vocal fold vibration—f0 and high frequencies that are multiples of f0. Filter: vocal tract—amplifies certain frequency components and weakens others depending on its configuration. Spectrogram and waveform: A spectrogram is a graph representation showing frequency, amplitude and time information. A waveform is a graph showing the amplitude of variation of air pressure of a specific point in a time course.

4