Obsolete term for a written character representing a sound, as opposed to a meaning. The modern term is 表音文字.
See also: 表音文字
The word 声音文字 was once used to refer to phonetic symbols, but it is rarely used today.
The modern standard term for phonetic symbols. 声音文字 is its obsolete predecessor.
Compound of 声音 (voice, sound) and 文字 (character, script). The exact historical derivation is uncertain; it was used as a term for phonetic writing before being replaced by 表音文字.