In articulatory phonetics, we investigate how speech sounds are produced using the fairly complex oral equipment we have. We start with the air pushed out by the lungs up through the trachea (or windpipe) to the larynx. Inside the larynx are your vocal folds (or vocal cords), which take two basic positions.

1 When the vocal folds are spread apart, the air from the lungs passes between them unimpeded. Sounds produced in this way are described as voiceless.

 2 When the vocal folds are drawn together, the air from the lungs repeatedly pushes them apart as it passes through, creating a vibration effect. Sounds produced in this way are described as voiced.

The distinction can be felt physically if you place a fingertip gently on the top of your Adam’s apple (i.e. that part of your larynx you can feel in your neck below your chin), then produce sounds such as Z-Z-Z-Z or V-V-V-V. Because these are voiced sounds, you should be able to feel some vibration. Keeping your fingertip in the same position, now make the sounds S-S-S-S or F-F-F-F. Because these are voiceless sounds, there should be no vibration. Another trick is to put a finger in each ear, not too far, and 26 The Study of Language produce the voiced sounds (e.g. Z-Z-Z-Z) to hear and feel some vibration, whereas no vibration will be heard or felt if you make voiceless sounds (e.g. S-S-S-S) in the same way.