TEXT 5 for questions 31-34

    Speech production is made possible by the specialized movements of our vocal organs that generate speech sounds waves.

    Like all sound production, speech production requires a source of energy. The source of energy for speech production is the steady stream of air that comes from the lungs, as we exhale. When we breathe normally, the air stream must vibrate rapidly. The vocal cords cause the air stream to vibrate.

    As we talk, the vocal cords open and close rapidly, chopping up the steady air stream into a series of puffs. These puffs are heard as a buzz. But this buzz is still not speech.

    To produce speech sounds, the vocal tract must change shape. During speech we continually alter the shape of the vocal tract by moving the tongue and lips, etc. These movements change the acoustic properties of the vocal tract which in turn produce the different sounds of speech.

32. What is the text about?