Tinnier refers to something that gives off a high-pitched, metallic sound. Synonyms for this word include piercing, sharp, shrill, cacophonous, clanging, clangorous, jangling, jangly, tinny, and trebly. Each of these synonyms has its own specific characteristics that differentiate it from the others. For instance, piercing and sharp both suggest a sound that is intense and painful to the ears, while shrill has a connotation of being unpleasantly high-pitched. Cacophonous refers to a harsh, chaotic sound, while jangling and clangorous imply a metallic, discordant sound. Overall, each of these synonyms can be used to describe a sound that is similar to tinnier but with its unique nuances.