Antonyms of "low tones" refer to sounds that are bright, sharp, or high-pitched. Such sounds can be described as high tones, loud, shrill, or piercing. These antonyms are often used to describe vibrant and energetic music, such as those produced by wind instruments or female vocalists. The opposite of a low tone can also be a passionate, intense, or expressive sound, as opposed to the subtle, muted tones of a low-pitched sound. In everyday language, antonyms for low tones might be referred to as sharp, bright, or upbeat sounds. The right antonym will depend on the context and nature of the sound in question.