Speech Speech Speech is human vocal communication using language. Each language uses phonetic combinations of a limited set of perfectly articulated and individualized vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are the same word, e.g., "role" or "hotel"), and using those words in their semantic character as words in the lexicon of a language according to the syntactic constraints that govern lexical words' function in a sentence. In speaking, speakers perform many different intentional speech acts, e.g., informing, declaring, asking, persuading, directing, and
Formant Formant In speech science and phonetics, a formant is the spectral shaping that results from an acoustic resonance of the human vocal tract. However, in acoustics, the definition of a formant differs slightly as it is defined as a peak, or local maximum, in the spectrum. For harmonic sounds, with this definition, it is therefore the harmonic partial that is augmented by a resonance. The difference between these two definitions reside in whether "formants" characterise the production mechanisms of a sound or the produced sound itself. In practice, the frequency of a spectral peak can differ from the associated resonance