Which of the following is NOT a visual clue to impairment?

The correct answer identifies enhanced hearing as not being a visual clue to impairment. Visual clues to impairment typically relate to observable behaviors that can indicate a person's level of functioning, especially in areas like coordination, reactions, and judgment.

When assessing someone for possible impairment, specific visual indicators such as poor coordination—where a person may struggle with balance or dexterity—can be directly observed. Additionally, slow reactions are also visible; for instance, if a person responds sluggishly to stimuli, that can be perceived through their actions or interactions. Impaired judgment, while more cognitive and subjective, can manifest visibly in choices or behaviors that are clearly irrational or unsafe in a given context.

On the other hand, enhanced hearing does not fall within this category. It may not be a symptom of impairment; in fact, some substances might even heighten a person's sensory perceptions. However, it does not lend itself to direct visual observation, which is key for identifying impairment through objective signs. Therefore, enhanced hearing is appropriately recognized as not a visual clue to impairment in the context of Standardized Field Sobriety Testing.