Heiban

Heiban, written with the kanji 平板 and literally meaning “flat,” is a term used in Japanese phonology to describe a specific pitch-accent pattern. In a heiban word, there is no downstep (no internal drop in pitch) within the word itself. The first mora is typically low, and the remaining moras of the word stay high until the end of the word. Because there is no internal nucleus of accent, the word is often described as unaccented or flat within the word.

In practice, whether a word is classified as heiban depends on the language variety being described. In Tokyo-style pitch accent, heiban is one of the common patterns alongside others such as atamadaka (accent on the first mora), nakadaka (accent on a later mora within the word), and odaka (accent near the end of the word). The distinction is important for predicting how pitch changes when particles attach to the word in connected speech. With a following particle, the pitch shift that characterizes the phrase may occur after the word boundary, rather than within the word.

Heiban is particularly associated with certain native and compound Japanese words and can vary by dialect. In many dialect descriptions, the term helps categorize words that do not display an internal downstep, in contrast to words with a clear accented mora. The concept is a standard part of discussions of Japanese pitch accent and is used to analyze intonation patterns in spoken language studies.