Sound waves and sound pressure waves are related concepts but differ in their specific definitions.
Sound waves refer to the propagating disturbances or variations in air pressure caused by a vibrating source, such as a speaker or musical instrument. When an object vibrates, it creates compressions (regions of high pressure) and rarefactions (regions of low pressure) in the surrounding medium, typically air. These compressions and rarefactions travel through the air as waves, forming what we perceive as sound. Sound waves are characterized by their frequency (pitch), amplitude (loudness), and waveform.
On the other hand, sound pressure waves specifically refer to the changes in air pressure caused by the sound waves. As sound waves travel through the air, they create alternating patterns of high and low pressure, leading to fluctuations in air pressure at a given point in space. The magnitude of these pressure fluctuations determines the sound's intensity or loudness. Sound pressure waves are commonly measured using a unit called the Pascal (Pa) or microPascal (µPa), which quantifies the pressure difference relative to atmospheric pressure.
In summary, sound waves represent the overall pattern of disturbance or variation in air pressure caused by a vibrating source, while sound pressure waves specifically describe the fluctuations in air pressure resulting from the propagation of sound waves.