声音 (shēng yīn) covers sound, voice, and noise depending on context. 声 refers to sound in general, while 音 refers to musical or tonal sound. Together they form the everyday word for any audible sound. For a human voice you can say 声音 or more specifically 嗓音 (sǎng yīn). Volume is expressed as 声音大小 (loudness) and turning up or down volume is 调高/调低声音.