The word "sonance" refers to a pleasing or harmonious sound, often used in relation to music or speech. Some antonyms for sonance might include discordance, dissonance, or cacophony, which all describe unpleasant or jarring sounds. Other opposites might include silence or stillness, which describe the absence of sound altogether. Non-musical antonyms might include chaos or confusion, which suggest a lack of order or structure. Additionally, antonyms for sonance might include words like monotony or repetition, which describe sounds that are dull or unvaried. Overall, there are many different words that reflect the opposite of sonance, representing a wide range of sounds and sensations.