The phrase "splits ears" can be replaced by several synonyms that convey the same meaning of a loud and jarring sound. One common synonym is "deafening," which describes a sound that is so loud it can cause temporary deafness. Another option is "ear-piercing," which suggests a sound that penetrates deeply into the ear. "Loud enough to wake the dead" is another idiom that can replace "splits ears" and implies a sound that is extremely loud and startling. "Thunderous" is a more poetic alternative and invokes the image of a resounding clap of thunder. Any of these synonyms can be used to describe a sound that is powerful and intense.