The word "more stridulous" means something that is louder or more harsh sounding. Some antonyms for this word would be "soft, gentle, quiet, or soothing." These words describe sounds that are more subtle and calming in nature, opposed to sounds that are clamorous and disquieting. These antonyms are often associated with peaceful environments, such as a quiet forest or a serene garden. Using these antonyms in writing or speech can help to create a more tranquil and relaxed atmosphere or tone. So, if you want to describe a sound that is not too harsh, you can use antonyms like soft, gentle, and soothing.