Final answer:
A sound wave is accurately described as a pressure wave, consisting of longitudinal motion of particles in the medium, creating periodic compressions and rarefactions. This scientific description captures the essence of how sound is generated and perceived within the audible frequency range.
Step-by-step explanation:
The statement 'A sound wave is a pressure wave; they can be thought of as fluctuations in pressure with respect to time' is true. Sound waves are indeed longitudinal, pressure waves, which move through a medium in the form of alternating compressions and rarefactions of the substance through which they are passing, whether it be air, water, or solids. These periodic variations in pressure are what we hear as sound. The molecules in the medium vibrate back and forth in the same direction as the wave travels, creating areas where they are pushed together (compressions) and areas where they are spread apart (rarefactions).
For example, a speaker produces a sound wave by oscillating a cone. This motion causes the air molecules around the cone to vibrate, forming compressions and rarefactions that travel through the air as sound waves. These pressure disturbances are audible to humans when they fall within the audible frequency range, which is typically between 20 Hz and 20 kHz.