What best describes the audiogram?

The audiogram is specifically a written record that displays an individual's hearing levels at various frequencies. This tool is essential in audiology for diagnosing hearing impairments and is typically used to assess how well a person can hear different pitches of sound, which are measured in Hertz (Hz). The results are plotted on a graph, allowing professionals to easily interpret a person's hearing ability across a range of frequencies.

The other options do not accurately describe an audiogram. A visual representation of sound waves pertains more to different aspects of acoustics and is not the purpose of an audiogram. A test for visual acuity relates to vision rather than hearing, while a chart indicating the frequency of injuries does not align with hearing assessment, as it deals with data related to safety and health incidents instead of auditory measurements. Thus, the definition provided in the correct choice is the most precise and relevant to what an audiogram represents.