contracted sound; palatalized sound
In Japanese phonology, refers to morae that combine a consonant with a small kana (ゃ, ゅ, ょ), such as きゃ (kya), しゅ (shu), ちょ (cho).
Sounds like 'kya', 'shu', and 'cho' are called yōon (contracted sounds).
contracted sound; open yōon
From 拗 (yō, 'twisted' or 'bent') + 音 (on, 'sound'), referring to the 'twisted' or modified pronunciation of these morae.