SPEECH

SPEECH
1. The primary form of LANGUAGE; oral COMMUNICATION in general and on any particular occasion: Most people are more fluent in speech than in writing.

2. A usually formal occasion when a person addresses an audience, often with the help of notes or a prepared text.

3. A way of speaking, often involving a judgement of some kind: local speech, slovenly speech, standard speech.

4. The field of study associated with speaking and listening: the science of speech.

Anatomy and physiology

Speech is possible because of the development over millennia of an appropriate physical system: the diaphragm, lungs, throat, mouth, and nose, working together. All such organs preexisted the evolution of language and have such prior purposes as breathing, eating, and drinking. With the advent of speech, they continued to perform these functions while becoming available for additional uses, so that two systems (maintenance of the body and systematic communication) exist side by side. Vocal sound becomes possible when a stream of air is breathed out from the lungs and passes through the larynx, then into and through the pharynx, mouth, and nose. This sound may be voiced or voiceless: that is, the larynx may vibrate or not. Different sounds are made in the mouth by moving the lips, tongue, and lower jaw to change the size and shape of the channel through which the air passes. A CONSONANT is made with a narrowing of the channel, and the point of maximum narrowing is the place (or point) of articulation for that consonant. The way in which this is done is the manner of articulation. A VOWEL typically has a wider channel than a consonant. Since it is difficult to be precise about the articulation of vowels, they are normally described by their auditory quality. In discussing articulation, phoneticians refer to an articulator, which may be active (as with the lips and tongue) or passive (as with the front teeth).

Place of articulation

For bilabial consonants, the narrowing is achieved by bringing the lips together. For labio-dental consonants, the active articulator is the lower lip. In other cases, the active articulator is part of the tongue, which is raised towards the passive articulator on the roof of the mouth: see table.

Sounds can be classified according to the active articulator, for example the tongue: apical sounds made with the tip (Latin apex); laminal sounds with the blade (Latin lamina); dorsal sounds with the back (Latin dorsum). Retroflex sounds are made with the tip of the tongue curled back behind the alveolar ridge towards the PALATE. However, the commonest classification is according to the passive articulator. This terminology assumes that the active articulator is the organ that lies opposite the passive articulator in the state of rest: for example, the passive articulator of a dental sound is the upper front teeth, and the active articulator is the tip of the tongue. If some other active articulator is used, it is specified explicitly: for example for /f, v/, the lower lip moves up to the upper teeth, and these sounds are labio-dental: see table. The ASPIRATE /h/ is usually described as glottal. In English, /h/ is like a voiceless vowel in that there is no fricative-like narrowing in the mouth, so that the greatest point of narrowing is in the glottis. Most sounds have one place of articulation, but /w/ has a double articulation, being made by simultaneously rounding the lips and raising the back of the tongue towards the VELUM. It is thus both bilabial and velar.

Manner of articulation

This refers mainly to the degree of narrowing at the place of articulation of a sound. If the airstream is blocked completely, the result is a STOP, such as /b/, but if it is narrowed to the point where noise or turbulence is generated as air passes through the gap, the resulting sound is a FRICATIVE /v/. In the case of an APPROXIMANT or continuant, the manner of articulation is more open, as with the /r/ of rink as compared to the /z/ of zinc (a voiced fricative). When a stop is released, the articulators move apart and necessarily pass through the degree of narrowing which produces fricative noise. A PLOSIVE is released quickly, whereas an AFFRICATE is released slowly:

plosives	/p, b; t, d; k, g/
affricates	/tʃ, dʒ/
fricatives	/f, v; θ, ð; s, z; ʃ, ʒ; h/

There are several types of approximant. The velum is normally raised to prevent air from entering the nose: a NASAL is produced with the velum lowered. The airstream normally passes centrally through the mouth: in the case of a lateral, the air escapes at the sides. The tongue normally offers a convex surface to the roof of the mouth: for an r-sound, the tongue surface is often hollowed out and the tip raised. A GLIDE or semi-vowel is vowel-like and moves rapidly into the following vowel, and cannot be prolonged:

nasals	/m, n, ŋ/
lateral	/l/
r-sound	/r/
glides	/j, w/

Phoneticians conventionally describe consonants according to their articulation.

Articulator		Description	Examples
Active	Passive
lower and upper lips	–	labial	/p, b, m/
lower lip	front teeth	labio-dental	/f, v/
tongue:
tip	front teeth	dental	/θ, ð/
tip	alveolar ridge	alveolar	/t, d, s, z, n, l, r/
tip/blade	ridge/palate	palato-alveolar	/ʃ, ʒ, tʃ, dʒ/
front	palate	palatal	/j/
back	velum	velar	/k, g, ŋ/