Which of the following is a symptom specifically associated with PCP use?

Hyperacusis, characterized by an increased sensitivity to normal environmental sounds, is specifically associated with phencyclidine (PCP) use. Users of PCP often report auditory distortions, which can include heightened sensitivity to sounds, making ordinary noises feel overwhelming or painful. This symptom arises due to the drug's effects on glutamate receptors and its impact on the central nervous system, leading to changes in perception and sensory processing.

Other symptoms associated with PCP use include agitation, hallucinations, and dissociative states, but hyperacusis stands out for its direct relation to auditory perception changes caused by the drug. The other options, such as hypotension or flushed skin, can occur with various substances or conditions and are not unique to PCP. Similarly, hypotonia, while it might relate to other central nervous system depressants, does not specifically point to PCP usage. Hyperacusis, however, is a particular auditory experience that aligns closely with the effects of PCP on the brain.