The phrase "clear as bell" typically suggests clarity, precision, and audibility. A few antonyms that come to mind would include the following: muffled, indistinct, jumbled, noisy, chaotic, and confusing. If something is not as "clear as bell" it might be difficult to understand, hard to hear, or simply disorganized in some way. When communication is not clear, it can lead to misunderstandings and misinterpretations. It is important to strive for clarity in all forms of communication, whether it be verbal or written, to avoid potential confusion and ensure that messages are accurately conveyed.