Phonetics is the study of how human beings produce and perceive speech sounds. In court cases, sometimes evidence is given in the form of a speech recording which phoneticians are frequently called upon to analyse. Imagine that the prosecutor is claiming that the voice in the recording is that of the defendant's. A phonetician would then be required to prove this right of wrong by analysing the articulatory and acoustic properties of the recording, something of which is allegedly as unique as a fingerprint.
The two classes of sounds
Sounds of all languages fall under two categories: Consonants and Vowels.
Consonants
All consonants may be classified as either voiced or voiceless. In articulating a voiced consonant, the vocal cords are vibrating. (The vibration may easily be felt by gripping the larynx--the "Adam's apple"--between the fingers and the thumb while articulating the consonant.) In articulating an unvoiced consonant, the vocal cords are not vibrating.
Present-Day English has several consonant pairs that are articulated alike except that one is voiced and the other is unvoiced. Some examples are the phoneme spelled b in bat (voiced) and the phoneme spelled p in pat (unvoiced); the phoneme spelled d in dab (voiced) and the phoneme spelled t in tab (unvoiced); the phoneme spelled th in this (voiced) and the phoneme spelled th in thistle (unvoiced).
Consonants may also be classified according to the manner of articulation and the point of articulation: that is, how and where the flow of air is stopped or impeded when the consonant is articulated. Thus, we get the following systems of classification.
Present-Day English has several consonant pairs that are articulated alike except that one is voiced and the other is unvoiced. Some examples are the phoneme spelled b in bat (voiced) and the phoneme spelled p in pat (unvoiced); the phoneme spelled d in dab (voiced) and the phoneme spelled t in tab (unvoiced); the phoneme spelled th in this (voiced) and the phoneme spelled th in thistle (unvoiced).
Consonants may also be classified according to the manner of articulation and the point of articulation: that is, how and where the flow of air is stopped or impeded when the consonant is articulated. Thus, we get the following systems of classification.
Vowels
Nasal vowel / Oral vowel
Previous Vowel / Later Vowel
Rounded vowel / Unrounded vowel
Open vowel / Closed vowel
Place or point of articulation
One of the differences between consonants and vowels is that when we articulate vowels, the airstream flows out freely along the middle of the tongue. When we articulate consonants on the other hand, we make some kind of obstruction in the speech organs, which prevents the air from flowing out freely. These obstructions may be made with for example some part of the tongue touching or approaching the roof of the mouth, or with the lips touching each other or the upper teeth, or by making an obstruction between the vocal chords. The parts of the speech organs which are involved in articulating consonants (tip of the tongue, lips, palate, teeth, vocal chords etc.) are called articulators.
Manner of articulation
Manners of articulation describe the kind of obstruction that takes place in articulation of the consonant in question.
Semivowels
Semivowels are vowel-like consonants: that is, the air-flow is not stopped or impeded so as to cause a friction-sound, but the aperture through which the air passes is smaller than the aperture of any vowel. Also, in forming words, semivowels appear in positions where consonants normally appear. Present-Day English has two semivowels, both of which are voiced (vocal cords vibrating during the articulation of the nasal). (The semivowels, the lateral /l/, the retroflex /r/, and the nasals are sometimes called the resonants.)
1. /w/ (the phoneme spelled w in wet): (voiced) bilabial velar semivowel. (This phoneme is bilabial because it requires rounding of both lips; it is velar because the back of the tongue rises toward the velum when the phoneme is articulated.)
2. /j/ (the phoneme spelled y in yard): (voiced) alveopalatal semivowel.
The parts of the human vocal apparatus
that are relevant to the description of English phonemes
Comentario » Comments »»» Blogger Facebook Disqus