Phonetics and Phonology
Before we start: Here you find some additional information on the anatomy of the larynx.
Function of the larynx: The larynx, composed of cartilage, held together by ligaments, sits on top of the trachea. Its box-like structure houses the vocal folds that lie behind the Adamís Apple. The gap between the vocal folds is called the glottis. The function of the larynx as a vibration source is termed phonation.
Voicedness and Voicelessness: The state of the glottis leads to different configurations for sounds known as voiced and voiceless sounds. If the vocal folds are apart (open), the air passes freely through the glottis. In this case the vocal folds do not cause any vibration. A sound that is produced in this way is called voiceless.
If the glottis is narrow, the vocal folds are brought together; the air passes through and causes the vocal folds to vibrate. As a result, the vibrated sound is called voiced (see also describing sounds).
Activity: Say a vowel /a:/ as in PALM. Prolong it. Press your hand on your larynx, and feel the buzz - the voicing. Now say a long /m/ and feel the same thing. Now say a long /s/. Go on and say a /z/. Prolong it. Can you feel hear the voicing for the /z/? Say /szszsz/ and feel the contrast of voiceless and voiced in these sounds.