1Sound or noise — any audible sound perceived by the ear. The everyday word for sound.
外から大きな音が聞こえてきた。
A loud sound came from outside.
ドアの閉まる音で目が覚めた。
I woke up to the sound of the door closing.
雨の音を聞きながら本を読むのが好きだ。
I like reading a book while listening to the sound of the rain.
テレビの音を少し小さくしてくれる？
Could you turn the TV down a bit?
2A musical note — a single pitch or tone in music.
高い音が出せるように練習している。
I'm practicing so I can hit high notes.
最後の音を外してしまった。
I missed the final note.
その曲は低い音が印象的だ。
That piece is notable for its low tones.
3Fame or reputation — used in expressions like 音に聞く to mean being known or reputed for something.
彼の腕前は音に聞く通り素晴らしかった。
His skill was as excellent as I had heard.
あの店は音に聞く名店だ。
That shop is famous, as I've heard.