Unit 2. The organs of speech (2014)Apunte Inglés
Apuntes creados a partir de las clases del profesor Joan Carles Mora y el libro de recomendación de Brian Mott.
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2. THE ORGANS OF SPEECH
Man’s speech apparatus consists of three parts:
I. The respiratory apparatus or lungs which provide the air which is used in the production of
most speech sounds.
II. The larynx, which generates most of the energy in speech sounds.
III. The supraglottal cavities, which act as resonators for the laryngeal tone.
2.2. The lungs and the act of respiration In the act of breathing, the lungs expand and contract. They expand as we take in air, and they contract as we breathe out. The cycle of breathing in and out takes about four seconds.
Although most speech sounds are produced on an egressive air stream, that is, while we are breathing out, it is also possible to speak on an ingressive air system, which we sometimes do when we are sobbing.
The type of sound known as implosives and clicks are made by drawing air in, rather than exhaling. Implosives are made on a glottalic ingressive airstream. In the production of implosive consonants, air is contained in the mouth and pharynx and larynx is lowered, thus rarefying it. When air is allowed to enter to the mouth gain, it rushes in with a hollow explosion.
Clicks are made with the mouth-air mechanism and the process involved is rather like kissing or sucking. The tongue makes contact with the roof of the mouth at two places and a vacuum is created. When air is allowed in to fill the vacuum, a clicking sound is heard. Clicks are generally marginal to language because these sounds have no phonemic status in our language.
Ejectives are made on a glottalic egressive airstream: the larynx is raised to compress the air trapped in the mouth and pharynx before it is released.
(Picture: the organs of speech) 2.3. The larynx The larynx is the hard casing around the vocal cords (Cubierta). It protects the cords from damage and, as it is a kind of valve between the lungs and the mouth, it plays an essential role in speech production, eating and breathing.
When we are eating the cords prevent the entry of foreign bodies into the windpipe.
By closing the cords and locking air in the lungs, we also assist in muscular effort of the arms and abdomen.
The vocal cords are two bands of elastic tissue lying horizontally across the larynx from back to front. They are joined at the front by the thyroid cartilage, and at the back by the arytenoid cartilages. The opening between the cords is known as the glottis. During normal breathing, the cords are wide apart so that the air from the lungs passes through freely without producing vibration.
In speech the cords may adopt thre principal positions: - wide open and not vibrating - close together and vibrating - tightly shut with the air from the lungs pent up behind them.
In the first instance, as the air from the lungs is unobstructed, we produce what are called unvoiced sounds (p,f).
1 If the cords are so close together that the air from the lungs makes them vibrate as it passes through the glottis, then we produce what we called voiced sounds (vowels, voiced consonants) In phonetics we can say that [p] is distinguished from [b] and [f] is distinguished from [v] by the voice correlation.
When the vocal cords vibrate, the speed of vibration varies. This speed (frequency, measured in hertz (hz)) is controlled by a combination of factors.
- The tension and length of the vocal cords which can be modified.
- The air pressure from the lungs which can be regulated.
The greater the air pressure from the lungs, the faster the vibration.
The faster the vibration of the cords, the higher the pitch of the note that is produced.
In normal speech, the frequency range is from about 60Hz to 350Hz. The human ear’s useful frequency range is very wide: 20-20,000Hz.
The power transmitted along a sound wave is called the intensity and is measured in decibels (dB).
Apart from variation in the frequency of vibration of the vocal cords, there may also be variation in the mode of vibration, giving rise to different types of voice. In normal voice, and average amount of air escaping from the lungs; this is the mode we use most of the time when we are speaking. But there also exist other types of voiced called creaky voice, breathy voice, and whisper or murmur.
- Creaky voice: it is produced when we are speaking under our breath, or to avoid disturbing people in the vicinity of the conversation, or in order to keep a conversation private.
- Breathy voice: the opposite of creaky voice in the sense that, instead of using weak breath force, we use strong breath force and expel the air rapidly from the lungs, in no more than two seconds.
- Whisper voice: the vocal cords vibrate but there is a considerable opening through which quite a lot of air escapes at the end of the cords beside the arytenoid cartilages.
A third consideration regarding the vibration of the vocal cords is the amplitude of vibration, which is related to loudness. The wider the cords move apart in the open phase, the louder the resultant sound will be.
(Picture: 1. How the glottis opens and closes / 2. The various states of the glottis When the vocal cords are tightly shut so that the air from the lungs builds up behind them, a glottal stop is produced if they suddenly open: - in the final [p], [t] and [k] are characteristically preceded by the glottal stop - can also actually replace other sounds in English rather than accompany them, which is often the case of non-initial - is also used to reinforce initial vowels in English. This abrupt beginning to vowels, which is not typical of Spanish, is known as the hard attack.
2.4. The supraglottal cavities There are three supraglottal cavities: - Pharynx, the area at the back of the mouth - Oral cavity/mouth - Nasal cavity 2 These cavities act as resonators for the sound generated by the vocal cords in the larynx.
(Pictures p. 50) The resonances set up in the vocal tract (which is the cavity we are mainly concerned with) are called formants and, as the vocal tract changes shape to produce different sounds, different formant frequencies come into play. Sounds are made up of many different formants.
The shape of the oral cavity is determined mainly by the movement of the tongue. This is the most elastic and mobile of the articulators (Active articulator as opposed to a passive articulator like the palate). It can be stretched (estirarse) forward in the mouth, retracted and bunched up (Amontonarse), and also move up and down while adopting these other positions so that either the front or the back or centre is raised or lowered.
- If the front of the tongue is raised half way bed If the back of the tongue is raised half way ball or bought If the front of the tongue is raised until it is fairly close to the palate leave If the tongue is lowered and retracted slightly live In the articulation of some sounds the lips play an important role. When sounds are produced with the lips pushed forward or protruded, we call them rounded or labialized. (Labialization correlation).
Consonants sounds are produced: - If we bring our lips and teeth into contact or into close proximity - If we raise the tongue so high that it almost makes contact or effectively touches the passive articulators.
This absence versus presence of contact between the organs is the basis of our physiological distinction between vowel and consonant articulations.
[t] the tip of the tongue is brought into contact with alveolar ridge (the hard gum ridge just behind the upper teeth). The flow of air from the lungs is momentarily obstructed. When the contact is released, we hear the characteristic explosion of [t] as the air escapes.
[k] the back of the tongue touches the velum [p] the lips are closed and then abruptly opened, but there is no voice Admission of air to the nasal cavity is controlled by the vellum. If the velum is raised and touched the back wall of the pharynx, then air passes exclusively through the mouth, thus producing oral sounds.
On the other hand, if the velum is lowered, so that air is allowed to enter the nasal cavity, then we talk of nasal or nasalized sounds.
The term nasal is for the consonants [m, n, ŋ]. Nasalized is applied to vowels since the passage of air through the nose in the case of vowels is concomitant with its passage through the mouth, there being no obstruction.
The equivalents of the nasal consonants [m, n, ŋ] are [b], [d] and [g] The nasalization correlation.
When the velum or soft palate is raised to shut off the nasal cavity, we speak of velic closure.
The expression velar closure refers to the action of raising the back of the tongue to the velum in the production of the consonants [k, g, ŋ].
2.5. Co-articulation We have spoken of the features like voice and nasalization as pertaining to individual sounds segments. But these feature can colour a sound system as a whole, so that different communities 3 and even individuals use particular voice settings or phonetic settings, which give, them their typical voice quality or timbre.
These long-term muscular adjustments of the vocal apparatus that put a muscular constraint on the speaker’s vocal performance and give it its auditory colouring can be divided into supralaryngeal settings and laryngeal settings.
Examples of supralaryngeal settings: 1. Lip-rounding 2. Whisper 3. Nasalization 4. Raised larynx 5. Lowered larynx 6. Retroflex articulation 7. Dentalized voice 8. Palatalized voice 9. Velarized voice Examples of laryngeal settings: 1. Creaky voice 2. Breathy voice 3. Harsh voice* * In harsh voice, the larynx is very tense and the ventricular folds or false vocal folds are pushed down onto the true vocal folds with the result that the speaker sounds angry and aggressive.
In English there are a number of alveolar consonants, so English tends to sound alveolarized.
The tongue-tip is used quite a lot.
English is also characterized by neutral lips held loosely apart, probably because [I] and schwa are very common, though there is occasionally more opening of the mouth for sounds like [ai], [au] and [ӕ].
(French is characterized by lip-rounding) The tongue is hardly ever visible in the English setting.