Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
VOICED AND VOICELESS SPEECH SOUNDS
Voiced sounds are those made while the vocal cords are vibrating: all vowels and some consonants (b, d, and g, for example) are voiced. Voiceless sounds (also called unvoiced sounds) are those made when the vocal cords are not vibrating (consonants p, t, and k, for example, are voiceless). Put a finger on your Adam’s apple, and say cut (KUHT) and gut (GUHT); you’ll feel the voiced vibrations of the g, but no vibrations from the voiceless k.
