Two terms I often use when writing about pronunciation are voiced and unvoiced. Apparently they are not as familiar in this context as I assumed they were. A reader has asked me to explain my use of them.
In one sense, to voice something is the same as to say or speak it:
Homeowners voice their concerns about increased earthquake activity.
Likewise, in some contexts, unvoiced means unspoken:
If people seem tense because of unvoiced disagreements, you may have to bring concerns out into the open.
In the context of pronunciation, however, voiced and unvoiced refer to consonant sounds that are uttered with the lips, tongue and teeth in the same position, but which produce different sounds.
Voiced sounds result when the vocal cords are touching and vibrate.
Unvoiced sounds are pronounced with the vocal cords apart.
For example, both sounds, /d/ and /t/ are uttered with the tongue in the same position, but the sound at the beginning of the word dog is voiced. The sound at the beginning of the word toy is unvoiced.
The following English consonant letter pairs represent voiced and unvoiced sounds:
b/p = boy, pit
d/t = dog, toy
v/f = van, fan
Note: The usual spelling for the unvoiced sound in this pair is f. An exception is the word of, in which the letter f represents the voiced sound.
j/tch = jet, witch
Note: The letter g represents two sounds. The “soft” sound is the same as that of the letter j. The “hard” sound belongs to the following consonant pair.
g/k = girl, kite
The letter s and the letter-combination th represent both voiced and unvoiced sounds:
s = music [voiced], sing [unvoiced]
th = they [voiced], thin [unvoiced]
The sound /zh/ is represented by the letter g in a few English words derived from French, such as genre and menagerie, but more often the sound /zh/ is spelled with the letter combination si: invasion, intrusion, vision. The /zh/ sound is also spelled with the letter s followed by u: visual, casual.
The unvoiced sound of /zh/ is /sh/, as in ship.
The sounds for the letters l, m, n, ng, and r are voiced. They do not have unvoiced equivalents in English.