Tones are compulsory elements of syllables in many of the world’s languages and contrast word meanings using differences in pitch (fundamental frequencies). For example, tones may be flat, rising, falling, or moving (contour tones). Tone languages are described as either simple or complex. Simple tone languages have two-way contrasts, often differentiating between high or low tones, whereas complex tone languages have more than two-way contrasts. Tones are different from intonation; tones relate to syllables whereas intonation relates to phrases and sentences. This entry describes the geographic distribution of tone languages, provides specific examples of such languages, and outlines the various methods of transcribing tones. This is followed by discussions of how children learn to identify and produce tones, the impact of communication disorders on tone ...