The words we speak travel through air , carried by vibrations  in the air. To create those air vibrations, we have an amazing speech system, which is much more than just our mouths.

Of course, we use air to breathe and live. But we also use air to speak and pronounce  words, and that is what this page explains in very basic terms.

Airflow

For every word that we speak, we can track the flow of air. It comes IN through our mouth/nose; it goes down our windpipe to our lungs. And then, to pronounce the word, it comes back up though our windpipe, and OUT through our mouth—and sometimes our nose.

As the air comes up from our (1) lungs , through our (2) voice box, and out through our (3) vocal tract—THAT is when we vibrate the air and change the "shape" of those vibrations to create different sounds, syllables and words.

1 Lungs

The lungs  are two elastic sacs in the chest that draw in air (mainly to oxygenate the blood). To initiate speech, they push air back up through the windpipe towards the voice box.

2 Voice Box

As air rises up from the lungs through the voice box in the neck, it may or may not be vibrated (so-called voiced and unvoiced sounds).

3 Vocal Tract

To control and shape the air flow above  the voice box, the air travels through and exits the vocal tract, which consists of:

  • the mouth  (oral cavity)—tongue, teeth, lips
  • the nose  (nasal cavity)

Using the vocal tract, we resonate the air and make two main types of speech sounds:

  • vowels
  • consonants

Speech Sounds

When we speak  in English, we use about 44 different sounds. When we write  in English, we use 26 letters  (the alphabet A-Z). You notice that there are more sounds than letters, and so there are not enough letters to represent all the sounds. It's important to understand that when we talk about speech and pronunciation, we are talking about the sounds of the phonemic chart, NOT the letters of the alphabet.

1 Vowels

A vowel  is a speech sound that we make by NOT blocking air as it travels out through the mouth.

example  vowel sounds:
/ ɪ / i: / ʊ / u: / e / ɜ: / ə / ɔ: /

2 Consonants

A consonant  is a speech sound that we make by blocking  air as it travels out through the mouth or nose. We block air by touching together two or more of the lips, tongue, teeth, top of mouth and back of throat.

example  consonant sounds:
/ p / f / θ / t / s / ʃ / ʧ / k /

Pronunciation

Syllables

A syllable  is a meaningless unit of pronunciation having one vowel  sound with or without surrounding consonant  sounds, like this:

 sounds 
 consonantvowelconsonantexamples
s
y
l
l
a
b
l
e
s		 V /aɪ/
 VC/ɒk/
CV /tə/
CVC/pəs/

Words

A word  is a meaningful unit of speech formed from one or more syllables. For example, I  is a one-syllable word and octopus  is a three-syllable word, as you see in the examples below:

wordnumber of syllables
II1
greengreen1
quitequite1
quietqui-et2
orangeor-ange2
tableta-ble2
octopusoc-to-pus3
interestingin-ter-est-ing4
unrealisticun-rea-lis-tic4
unexceptionalun-ex-cep-tio-nal5

One or more words can form a sentence.

Summary

  • The lungs push air up for speech.
  • In the voice box, air passing through can be voiced or unvoiced.
  • In the vocal tract, unblocked air makes vowels  and blocked air makes consonants.
  • Vowels and consonants make syllables.
  • Syllables make words.
  • Words make sentences.

vibrate  (verb): move fast and continuously backwards and forwards

vibration  (noun): an example of vibrating

throat  (noun): the passage that leads from the back of the mouth

windpipe (noun): the air passage from the throat to the lungs; the trachea

oxygenate (verb): charge or enrich with oxygen

oxygen (noun): a colourless gas in air that is essential for life

initiate (verb): cause a process to begin

meaningless (adjective): having no meaning or significance

meaningful (adjective): having meaning or significance

sources : Original Link