What is measured in decibels and relates to the pressure produced by a sound wave?

The correct answer is amplitude. Amplitude refers to the height of the sound wave, which directly relates to the pressure produced by that wave. In terms of sound measurement, a higher amplitude indicates a louder sound, measured in decibels (dB). This concept is fundamental in understanding how sound intensity is perceived by listeners.

Frequency, on the other hand, refers to the number of cycles of a sound wave that occur in a second, which determines the pitch of the sound rather than its loudness. The outer ear is part of the anatomy responsible for capturing sound but does not inherently measure sound characteristics like amplitude. The cochlea, located within the inner ear, is involved in the process of translating sound waves into neural signals for the brain but does not measure sound in decibels itself. Understanding these distinctions clarifies why amplitude is the correct choice when discussing sound pressure and its measurement.