The word "震耳欲聋" is formed by combining four characters: 震 (to shake), 耳 (ear), 欲 (about to), and 聋 (deaf). Literally, "震耳" means "shaking the ear", and "欲聋" means "about to become deaf", so together they create a vivid description of a sound so intense that it violently affects the ear and is on the verge of causing deafness, thus conveying the meaning of "ear-splitting" or "deafening".