[ I or T ] to change the style, loudness, etc. of something such as your voice in order to achieve an effect or express an emotion改变（嗓音）的音量（或音质等），调节（声音）

[ I ] specialized to change from one musical key to another（音乐）变调

[ T ] formal to change something, such as an action or a process, to make it more suitable for its situation调节，调整

[ T ] specialized media to mix an electrical signal that represents sounds or pictures with a radio signal so that it can be broadcast调制（无线电波）；调谐