The antonyms for the word "more deep-toned" would be lighter, higher-pitched, and shriller. When it comes to describing sound, deep-toned refers to a low, resonant, and full-bodied sound. On the other hand, light-toned is the opposite characteristic, and refers to a sound produced at a higher frequency with a softer and milder quality. Higher-pitched also suggests a sound with a sharper and brighter tone, while shriller means penetrating and harsh. When we use antonyms, we create a contrast between different aspects of the same idea, and this opposition helps us to better understand the meaning of the original word.