(phonetics, prosody) metathesis (the transposition of letters, syllables or sounds within a word)

(linguistics) sound shift / (linguistics) sound shifts from Old Japanese to Modern Japanese, especially those which are preserved in historical kana usage.

Kyūjitai form of 音楽学 (“musicology”)

soundproofing material; sound-absorbing material

car horn

(Internet slang) Tokutei Asia (East Asian countries which have obvious negative views of Japan)

(phonetics) phonetic symbol

speech organ

secondary audio channel in a multiple audio channel television broadcast (音声多重放送), used for commentary, audio in another language, etc.

(physics) infrasound