What are the two key characteristics of noise?

The two key characteristics of noise are frequency and intensity. Frequency refers to the number of vibrations or cycles per second of a sound wave, which determines the pitch of the sound. Intensity, on the other hand, refers to the loudness or amplitude of the sound wave. Together, frequency and intensity allow for the complete characterization of a sound's auditory properties, which is essential in understanding the impact of noise in environments, particularly in fields such as aerospace physiology where exposure to noise can affect performance and well-being.

Other characteristics listed in the other options, such as duration, distance, pitch, and clarity, play roles in specific contexts of sound perception but do not encompass the primary measurements of noise itself. Duration touches on how long the noise lasts, while distance relates to how far the sound travels before reaching the listener. Pitch is associated with frequency but does not encompass the broader aspect of sound measurement. Clarity refers to the quality or distinctness of the sound rather than a defining characteristic of noise.