Final answer:
Intensity or loudness of a sound is related to sound intensity, which is the power per unit area carried by the wave and depends on the wave's pressure amplitude. The loudness of sounds is appropriately quantified in decibels.
Step-by-step explanation:
Intensity or loudness is related to the power per unit area carried by a sound wave. A useful quantity for describing the loudness of sounds is called sound intensity. Sound intensity (I) is defined in equation form as I = P/A, where P is the power through an area A, with the SI unit for I being Watts per square meter (W/m²). The intensity of a sound depends upon its pressure amplitude; higher amplitude means greater pressure maxima and minima, resulting in a louder sound and increased intensity.
The relationship between blood volume, pressure, and flow does not directly determine the loudness of a sound. However, when one is in a quiet environment, such as a quiet forest, subtle internal sounds like the blood pulsing through the ears may become noticeable. The unit of measuring sound intensity is the decibel (symbol: dB), which quantifies the intensity of a sound relative to a reference level, indicating its amplitude and perceived loudness.