Phonetics is the study of all the raw speech sounds or phones that are produced within a specific language and their description in terms of the manner in which they are physically produced by the vocal apparatus. Sounds vary according to the positions of speech organs, the points of articulation, and the control of the air flow, the manner of articulation.

Points of articulation

Bilabial articulation Dental articulation Labiodental articulation Alveolar articulation
Velar articulation Palatal-alvelar articulation Palatal articulation Retroflex articulation
For example, a "t" sound in English is identified as alveolar (using the hard palate), unvoiced (not using the vocal cords), plosive (enunciated by blocking and then suddenly releasing the air flow from the lungs). The sound is also aspirated, i.e., there is a puff of air released after its production.

Some attempt has been made to exhaustively document the myriad speech sounds forms by the International Phonetic Association, through the publication of the International Phonetic Alphabet (IPA). Linguists and linguistics students conventionally use this alphabet rather than standard orthographics when they record and publish language texts. Standard orthography, rather than the IPA, will be used in this unit. Accordingly, readers must be aware that the spelled forms do not accurately depict the actual phones represented, a problem that does not occur when IPA orthography is used. As an example of IPA use, consider the following, which you can try to decipher.

The character of variations in speech sound selection and patterning in different languages can be illustrated by some features of French and English phonetics. We have already described the English "t" sound as an unvoiced aspirated alveolar plosive. French also has a "t" sound that is similar to the English phone, but is actually produced by placing the tongue on the teeth rather than the hard palate. Thus the French "t" is defined differently as an unvoiced aspirated dental plosive and is represented by a different character in the International Phonetic Alphabet. The difference between the "t's" in the two languages can be heard in the production of the words:

"bait" (English)

"bête" (French: stupid)

The difference identified is not restricted to the "t" sound alone but is systematically applied to other phones through systematic phonological rules appropriate to the language. The French dental "t" derives from a wider practice preferring the teeth to the alveolar ridge as a point of articulation. Thus the "l" sound, which is articulated on the hard palate in English, is produced in French by placing the tongue on the upper teeth, is audible in the difference between

"bell" (English)

"belle" (French: beautiful)

This regular selection of regular points and manners of articulation results in the formation of sound series in the language, i.e., an alveolar series in English and a dental series in French, and is a major feature of systematic phonetic patterning.

A more extreme difference in "t" sounds can be observed by comparing English and Zulu. Zulu includes an alveolar "t" equivalent to the English form but through a manner of articulation involving a closing of the air passage, the creation of an oral vacuum, and a sudden release of the stop. This articulation results in a "click" similar to the noise in English usually represented by "tsk". This manner of production is systematically applied at other points of articulation producing a whole click series: a bilabial click (similar to a kissing sound), a alveolar click (the "tsk" sound), and a velar click, produced in the back of the throat.

Note: The images and animations on this page were    provided courtesy of Ali Morawej, of the Department of Electrical Engineering, University of Manitoba. You might like to view his groundbreaking Articulating Speech and Hearing Perception Project site, on which he has developed computerized illustrations and models of speech production for use in speech therapy. (Access requires a password, but you may sign in as a guest.)