Which of the following statements is true about sound waves?

The correct statement regarding sound waves is that humans hear by sensing sound waves that result from changes in the pressure of air or water. This is fundamental to understanding how auditory perception works. Sound waves are created by vibrations that cause fluctuations in air pressure, which then propagate through the medium (be it air, water, or solid materials). When these waves reach our ears, they cause the eardrum to vibrate, which is then translated into neural signals that the brain interprets as sound. This process highlights the importance of the physical mechanism through which we perceive sounds.

In contrast, while other statements mention related concepts, they are not accurate: sound waves do not travel faster than light waves, as light speed in a vacuum is constant and significantly faster than sound. Additionally, the frequency of sound waves affects the pitch perceived by the listener, whereas loudness is more closely associated with amplitude. Lastly, pitch is determined by frequency, not amplitude. Understanding these distinctions is crucial in the study of sensation and perception in psychology.