Sounds of Speech as Acoustic

And Articulatory Units

 

1) Acoustic aspect of speech sounds.

2) Articulatory and physiological aspect of speech sounds.

 

Acoustic aspect of speech sounds

 

Acoustically, speech sound is a physical phenomenon produced by the vibration of the vocal cords and perceived due to the vibrations of the air which occur at the rate of 16 to 20 thousand times per second.

Sounds may be periodical and non-periodical. The auditory impression of periodic wares is a musical tone or a speech tone. If the vibrations are not rhythmical we hear noises.

Sound has a number of physical properties:

- frequency (the number of vibrations per second)

- intensity Changes in intensity are perceived as variation in the Loudness of a sound.

- duration – it is the length of the sound or quantity of time during which the same pattern of vibration is maintained.

Other acoustic characteristics of speech sounds are fundamental frequences or musical tones and overtones or harmonics.

 

Articulatory and physiological aspect of speech sounds

 

Speech is impossible without the following 4 mechanisms, which work simultaneously.

(1) the power mechanism

(2) the vibrator mechanism

(3) the resonator mechanism

(4) the obstructer mechanism

The power mechanisms consists of the diaphragm [ ], the lungs, the bronchi, the windpipe (or trachea) [ ] the glottis, the larynx, the mouth cavity and the nasal cavity.

The vibrator mechanism (or the voice producing mechanism) consists of the vocal cords, they are in the larynx. The vocal cords are 2 horizontal folds of elastic tissue. They may be opened or closed completely or incompletely. The pitch of the voice is controlled mostly by the tension of the vocal cords. 3 speech sounds are produced by the vocal cords: h,, its voiced allophone and glottal stop [?]

The resonator mechanism consists of the pharynx, larynx, the mouth cavity and the nasal cavity.

The obstructer mechanism consists of the tongue (blade with the tip, front, back): the lips, the teeth, the soft palate with the uvula, the hard palate, the alveolar ridge.

Articulatory differences between vowels, consonants and sonorants depend on the 3 articulatory criteria:

1. the presence or absence of an articulatory obstruction to the air stream in the larynx or in the supra-glottal cavities;

2. the concentrated or diffused character of muscular tension;

3. the force of exhalation.

On the basis of these criteria consonants may be defined as sounds in the production of which a) there is an articulatory obstruction to the air stream (complete or incomplete), b) muscular tension is concentrated in the place of obstruction; c) the exhaling force is rather strong.

Vowels may be defined as sounds in the production of which a) there is no articulatory obstruction to the air stream; b) muscular tension is concentrated more or less evenly throughout the supra-glottal part of the speech apparatus; c) the exhaling force is rather weak.

Sonorants are sounds intermediate between noise consonants and vowels because they have features common to both. There is an obstruction, but not narrow enough to produce noise. Muscular tension is concentrated in the place of obstruction, but the exhaling force is rather weak. English sonorants are [m, n, ŋ, l, w, r, j].

 

Articulatory and physiological classification of English consonants according to the following pronounles:

 

I. Work of the vocal cords and the force of exhalation.

II. Active organ of speech and the place of obstructor.

III. Manner of noise production and the type of obstruction with the following subdivisions:

(1) voice or noise prevalence

(2) number of noise producing foci

(3) shape of the narrowing

IV. Position of the soft palate

 

I. Consonant are subdivided into

- voiced – vocal cords are drawn together and vibrate

- voiceless – vocal cords are apart and don’t vibrate

Voiced consonants are also called “fortis” (Latin) – the force of exhalation is greater and “lenis” – soft, when the force of exhalating is weaker.

II. Consonant are classified into:

- labial – bilabial and labio-dental

- lingual – a) forelingual – dorsal,, θ, apiсal, cacuminal

b) medio-lingual

c) backlingual

- pharyngal or glottal – h

 

III. From the point of view of the closure consonants may be of (1) occlusive when complete closure is made (p, b, t, d, k, g, m, ŋ); (2) constrictive, when the closure is incomplete (f, r, θ, w, l, r); (3) occlusive-constrictive or affricates, when the combination of 2 closures takes place [t∫, d ]; (4) rolled-intermittent closure – Russian p. Some phonetic include in the 3^rd group lateral, nasals and semivowels.

 

IV. – Oral-soft palate is raised and the air passes through the larynx and month cavity

- Nasal consonants – soft palate is lowered and the air passes through the nasal cavity [m, n, ŋ]

 

Articulatory and physiological classification of English vowels

 

The most general classification of vowels is according to:

I. Position of the lips

II. Position of the tongue

III. Degree of tenseness and the character of the end of a vowel

IV. Length

V. Stability of articulation

 

I. a) rounded u – u: É - É:

b) unrounded

 

II. Most scientists divide vowels according to the

a) horizontal

b) vertical movements of the tongue

 

a) When the bulk of the tongue moves backwards, it is usually the back part of the tongue which is raised highest towards the soft palate. Vowels produced with the tongue in this position are called back. They are subdivided into: - fully back [É É: u: É I ]

- back – advanced [Ù u a:] ou u¶

 

When the bulk of the tongue moves forward, it is usually the front part of the tongue which is raised highest toward the hard palate. Vowels produced with this position of the tongue are called front. They are subdivided into:

- fully front [I: e æ eI з æ∂ aI]

- front – retracted [I au]

 

Vowels [∂ ∂:] are considered by British phoneticians to be central. Daniel Johes says that the central part of the tongue is raised highest and it is pronounced at the junction between “front” and “back”. Russian phoneticians consider it as mixed

b) According to the vertical movements of the tongue vowels are subdivided into:

high i: I u u:

mid, half open e ∂: Î(∂) É(u)

low, open Λ É: æ a: É É(I) a(I,u)

Each of the subclasses is subdivided into vowels of narrow variation and vowels of broad variation:

narrow variation I: u:

high

broad I u

narrow variation e ∂: o (u)

mid

broad Î(∂) ∂

narrow Λ É:

low

broad a: É æ a (I, u)

 

 

III. According to the degree of tenseness traditionally long vowels are defined as tense and short are lax. But there are different opinions this problem.

 

IV. According to the length vowels are subdivided into (historically) long and short. Vowel length depends on a number of linguistic factors:

(1) position of the vowel in a word,

(2) word accent

(3) the number of syllables in a word,

(4) the character of the syllabic structure,

(5) sonority.

 

(1) In the terminal position a vowel is the longest, it shortens before a voiced consonant, it is the shortest before a voiceless consonant

be – bead – beat

(2) A vowel is longer in an accented (stressed) syllable, than in an unaccented one

‘Forecast (прогноз) - fore’cast (предсказывать погоду)

(3) In polysyllabic words similar vowels are shorter than in one – syllable words

verse - university

∂: (longer) ∂: (shorter)

(4) In words with V, CV, CCV type of syllable the vowel length is greater than in words with VC, CVC, CCVC type of syllable

e.g. [u:] is longer in dew (CV type) than in duly (CV type)

(5) Vowels of low sonority are longer than vowels of greater sonority. It is so, because the speaker unconsciously males more effort to produce greater auditory effect while pronounciry vowels of lower sonority, thus making them longer.

e.g. I is longer than É:

I: is longer than a:

D. Jones treats quantity independently of the vowel sounds themselves. Thus he treats I: and I as positional allophones of one phonemes.

 

V. Stability of articulation can be treated conventionally. We can speak only of relative stability of the organs of speech, because pronunciation of a sound is a process.

According to this principle vowels are subdivided into:

(a) monophtongs or simple vowels

(b) diphtongoids

(c) diphtongs or complex vowels

(a) English monophtongs are pronounced with more or less stable lip, tongue and the mouth walls position. I e

(b) A diphthongoid is a vowel which ends in a different element. There are 2 d – ids in English I: u:

(c) Scientists define diphthongs as one simple sound.

 

D. Jones defines diphthongs as an unisyllabic gliding sound in the articulation of which the organs of speech start from one position and then glide to the other position. The 1^st element of a diphthong is the nucleus, the second is the glide.