In this section, we study the behavior of our vocal mechanism. Despite the fact that there are many aspects of this system that we do not completely understand (particularly around the vocal folds), our ability to conduct experiments with our own speech mechanism allows us to quickly verify much of its behavior.
The smallest units of speech sounds are called phonemes. One or more phonemes combine to form a syllable, and one or more syllables to form a word.
Phonemes can be divided into two groups: vowels and consonants. Vowels are always voiced.
There are approximately 12 to 21 different vowel sounds used in the English language. Discrepancies usually are due to disagreement over what constitutes a pure vowel sound rather than a diphthong (a combination of two or more vowels into one phoneme).
Consonants involve rapid and sometimes subtle changes in sound.
Consonants may be classified according to their manner of articulation as plosive (p, b, t, etc.), fricative (f, s, sh, etc.), nasal (m, n, ng), liquid (r, l), and semivowel (w, y).
Consonants are more independent of language than vowels are.