The American Heritage® Dictionary of the English Language, 4th Edition
n. Any of several frequency regions of relatively great intensity in a sound spectrum, which together determine the characteristic quality of a vowel sound.
n. A band of frequencies, in a sound spectrum, that have a greater intensity; they determine the quality of a sound; especially the characteristic sounds of the consonants.
The Century Dictionary and Cyclopedia
n. In phonology, the name given by Hermann to “the tone of constant pitch for each vowel,—independent of the tone on which it is sung.”
Word Usage
"'Pitch' 'formant'"amount of air flow 'to control the machine like a human laugh.""