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How Speech is Produced

As you know, speech is made up of different sounds put together in different combinations to form words. Every language has its own unique system of sounds and ways of combining these sounds. Before taking up the sound system of American English, it is helpful to have a basic understanding of how speech is produced or made.

The first thing you need for speech or talking is sound. You must produce an audible tone or sound, and the source for speech sounds is the air stream coming from your lungs. During normal breathing, this air stream is inaudible. During speech, the vocal cords in the throat (voice box) open and close rapidly, breaking up the air stream into a series of puffs. That is, the air is set into vibration, which produces sound.

Try it now. Take a breath, open your mouth and say “ah.” This is the basic way sound is produced. Try it again. This time hold your hand firmly against the front of your throat, over your voice box. As you say “ah”, feel your throat vibrate. Next, try making the “ee” sound in the word “see”. Notice that your mouth is almost closed when you make this sound. Now alternate between the “ah” and “ee” like this: “ah-ee-ah-ee”. Feel your mouth open and close and change its shape. This is one way you produce different sounds, by changing the shape of your mouth.

The sounds of language are divided into two main groups: vowels and consonants. The “ah” and “ee” are examples of vowel sounds. The primary distinction between vowels and consonants is that 1) for vowels, the air stream flows freely through the mouth and 2) for consonants, the air stream is blocked or obstructed by the lips, tongue, or teeth and does not pass freely through the mouth.

Another distinction is that the vowel forms the core of a syllable, i.e., the syllable functions as an independent unit of speech that can stand alone without an accompanying consonant. Consonants, on the other hand, cannot stand-alone or function as independent units of speech.

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Phonetic Symbols

In most languages, the letters of the alphabet used for spelling do not always correspond exactly to the actual speech sounds. This is especially true for English, as you are well aware, and some of your difficulties with English pronunciation are most likely a direct result of this fact. Let us consider a few examples of the discrepancies between spelling and pronunciation:

1) often words have more letters than sounds as in the word “shoe” which has four letters but only two sounds;

2) the letter may have no relation to the sound as in the word “phone” which is pronounced as “fone”, or the word “of” pronounced as “ov”;

3) words may be spelled differently but pronounced the same as with the words, “to, too, two”;

4) words may be spelled the same but pronounced differently as with the verb “use”, pronounced as “uze” and the noun “use”, pronounced as “use”;

5) different letters may be used for the same sound such as the words “keep” and “cook” in which the beginning letters “k” and “c” are both pronounced as “k”;

6) some letters may be silent such as the letter “b” in the word “thumb”, the letter “k” in the words “know”, and the letter “t” in the word “listen”. These are only a few examples of the limitations of English spelling, and you will probably think of many more from your own personal experience.

Because of the inherent ambiguity in attempting to discuss the sounds of English using the conventional alphabet and spelling system, it is helpful, if not necessary, to use phonetic symbols. The symbols used to discuss sounds are typically adopted from the International Phonetic Alphabet or IPA. The IPA is the system commonly used for research and language teaching purposes and includes symbols for most of the sounds of the World’s languages.

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Vowel Sounds of American English

There are thirteen phonetic symbols for vowels but, in English spelling, there are only five letters to represent these sounds. This is why the English spelling system for vowels is often confusing and difficult to learn. Consequently, to accurately represent each of the vowels, it is necessary to use a number of additional symbols that are not contained in the standard alphabet.

Unlike the consonants, which may be produced with or without voicing, the vowels are always produced with voicing (vibration of the vocal cords). The particular vowel that is produced is determined by the degree of opening in the mouth and the position and shape of the tongue and lips.

For example, if you make the vowel /i/ as in the word “see” and then the vowel /u/ in “Sue”, you will notice that your lips are rounded for the /u/ , but not for the /i/. Now, lets add the vowel /ʌ/ as in the word “but”, and then make the sequence of sounds /i-ʌ-u/. Feel your tongue move from the front of your mouth to the back. This is because the tongue is raised or bunched in the front of the mouth for /i/, and then moves to the middle for /ʌ/, and then to the back for /u/. Thus, the positioning of the tongue in the mouth (front, middle, back) is one of the primary ways of classifying the vowel sounds.

Front Vowels

This first group of vowel sounds, /i, ɪ, e, ɛ, æ/, is called front vowels because they are produced with the highest part of the tongue arched towards the front of the mouth.

Central Vowels

The next group of vowels, /ʌ, ə/ and /ɝ, ɚ/, is called central vowels because they are produced with the tongue arched in the center of the mouth, i.e., midway between the front and back. These vowels are further distinguished according to whether they are stressed or unstressed. To illustrate, say the words “but” and “about”, and you will observe that the vowel in “but” and the first vowel in ‘about” are nearly the same. The main difference is that the vowel in “but” is stressed, and the vowel in “about” is unstressed, i.e., it occurs in an unstressed syllable. This difference is represented phonetically by using the symbol /ʌ/ for the stressed form of the vowel and /ə/ for the unstressed form.

Similarly, the symbols /ɝ/ and /ɚ/ are used to distinguish between the stressed and unstressed form of the /r/-vowel. The symbol /ɝ/ is used for the stressed vowel in words like “bird” and “nurse”, and the symbol /ɚ/ is used for the unstressed form in words like “mother” and “later”. Like the /r/-consonant, the /r/-coloring of the /r/-vowel is produced by a slight curling of the tongue tip.

Back Vowels

The next group of vowels, /u, ʊ, o, a/, is called back vowels because they are produced with the back part of the tongue arched toward the back of the mouth. The three vowels /u, ʊ, o/ also differ from all of the other vowels because they are produced with a higher degree of lip rounding. Listen to the back vowels in the sample words and try saying them to familiarize yourself with the sounds and symbols.

Diphthongs

The sounds in the last group, /ai, au, oi, iɚ, eɚ, oɚ, aɚ/, are combinations of vowels that function as single vowels. They are produced by starting with one vowel and then gliding or moving to another vowel. They are characterized by a constantly changing quality, and the symbols used to represent them are only suggestive of their starting and ending point. There are many different possible diphthongs besides those included here, but these are some of the most common ones and will serve to acquaint you with this type of sound.