A nurse is conducting an audiometry test to differentiate between loudness and intensity of sound for a patient with suspected hearing loss. Which statement correctly distinguishes loudness from intensity?

Choice A rationale This statement incorrectly identifies the units of measurement for these properties. While intensity is indeed measured in decibels, which is a logarithmic unit expressing the ratio of sound power, loudness is a subjective sensation and does not have a physical unit like hertz. Hertz is the unit of frequency, which describes the pitch of the sound. Therefore, equating loudness to hertz is scientifically inaccurate in the context of human auditory perception and physics. Choice B rationale This statement misrepresents the physical characteristics of sound. Intensity relates to the amplitude of sound waves and the energy they carry per unit area, not the frequency. Frequency determines the pitch, not the intensity. Furthermore, loudness is the psychological correlate of amplitude, while duration is a separate temporal aspect of sound. These definitions do not correctly distinguish how a patient perceives sound versus how sound energy is physically measured during an audiometry test. Choice C rationale This statement correctly distinguishes between the two concepts. Intensity is an objective, physical property of sound waves that can be measured using instruments; it is expressed in decibels where 0 decibels represents the threshold of human hearing. Loudness, however, is a subjective psychoacoustic attribute. Two sounds with the same measured intensity may be perceived as having different loudness by different individuals, depending on the frequency and the health of the patient's auditory system. Choice D rationale This is incorrect because loudness is not an objective measurement. While intensity can be quantified using calibrated audiometers to provide a specific decibel level, loudness varies based on individual perception, ear anatomy, and neurological processing. In clinical audiometry, the nurse measures the intensity required for the patient to perceive a sound, but the "loudness" is what the patient actually feels or reports, making it a subjective experience rather than a direct objective measurement.