Introduction to Sound
Letters and sounds
The modern English alphabet (also called the modern Latin alphabet) has 26 letters. Five of these letters (a, e, i, o, and u) are vowels and the remaining 21 are consonants. These 26 letters, alone or in combination, are used to spell the 43 sounds of English.
The fact that there are more sounds than letters in the English language complicates the process of learning English pronunciation. Many consonant sounds are spelled as digraphs, or combinations of several letters representing only one sound. Commonly known and accepted examples are the th spelling of the words them and think and the sh spelling of the word she. If that weren't complicated enough, it is also the case that the sh sound can be spelled with the letters ch, as in the words chef, and machine.
Common vowel spellings are even more difficult to master. In addition to many possible combinations of the five letters that comprise English vowels, the letters w, y, and the digraph gh can form part of the spelling for a vowel sound, as in the words down, day, and eight, respectively. The letter y alone, although it is not commonly regarded as a vowel, can represent a vowel sound, as in the word myth.
Consonant sounds versus vowel sounds
Consonant sounds are generalized as being sounds that either push air through a constricted opening in a vocal tract, or briefly and completely stop the air, then release it. As an example of constricting air, notice the first sound of the word see. In contrast, the word be begins by using the lips to stop the air completely. There are also some consonants that behave a bit like a vowel sound as well as a consonant sound. These sounds are called semi-vowels, and the w sound is an example of one. The word we begins with a w sound.
The English sound system allows both voiced and unvoiced consonant sounds. Voiced sounds are created when the vocal cords vibrate during the sound's production, and unvoiced sounds are created without this feature. Many consonant sounds occur in voice and unvoiced pairs, meaning the overall articulation for both sounds is the same, and the major difference is whether the vocal cords are made to vibrate or not. Examples of these pairs include the t sound and d sound, the p sound and b sound, and the s sound and the z sound.
Vowel sounds are all voiced and are characterized by having a more open vocal tract during their production, as well as being syllabic. A syllabic sound is a sound that forces a syllable to occur. Each syllable of a word has one, and only one, syllabic sound; therefore, there can be no more than one vowel sound per syllable.
While the base of most syllables is a vowel sound, it is also possible for specific consonants (called syllabic consonants) to fill this core function. English has three syllabic consonants, schwa+r, the l sound, and the n sound. The l sound and n sound are only syllabic when the syllable they exist within has no accompanying vowel sound, while schwa+r is always a syllabic consonant (when it is not syllabic, it is just called an r sound). In addition, the l sound and n sound can only be syllabic on an unstressed syllable, whereas schwa+r can occur on either a stressed or an unstressed syllable.