Auditory hallucinations are defined as perceptions of sound that are not actually present in the environment. There are different synonyms that can be used to describe this phenomenon. For instance, one synonym is "hearing voices," which refers to the experience of hearing someone or something speaking when there is no one around. Another synonym is "acoustic hallucination," which is a more technical term that emphasizes the sensory nature of the experience. Similarly, "auditory illusion" can be used to describe a false perception of sound that is created by the brain. Other possible synonyms for auditory hallucination include "sonic hallucination," "sound hallucination," and "audio hallucination".