Piercingness is a term that is mainly used to describe the intensity of a sound or noise. There are several synonyms for this word that can be used to describe this phenomenon more accurately. Some of these synonyms include sharpness, shrillness, penetration, and acuteness. Each of these words has slightly different connotations, but they all describe a high-frequency sound that is immediately noticeable and can be somewhat discomforting. Synonyms like these are often used in music and audio production to fine-tune and adjust the overall sound of a piece. Ultimately, the right synonym for piercingness depends on the context and the intended effect.