Consonants that are "voiced" are those whose sound comes from the vibration of the vocal cords. One way to tell is to put your fingers on your throat, and if you feel your larynx (voice box) vibrate, the consonant is voiced. Another way to experiment is to put your fingers in your ears, and if, when you say the consonant aloud, you can still hear the sound through vibrations in your head and neck, it is voiced. An unvoiced consonant makes its sound by way of the air moving through your tongue, lips, and teeth. For example, though the consonants "b" as in "ball" and "p" as in "pea," are similar, the letter "b" is voiced, where "p" is not. Likewise, "z" in "zoo" is voiced, and "s" in "see" is not. Try saying each of them with your fingers on your throat, and you will find an obvious difference!