What term describes the measure of how much a medium obstructs sound waves?

The term that describes how much a medium obstructs sound waves is acoustic impedance. Acoustic impedance is a fundamental concept in auditory physics that quantifies how difficult it is for sound waves to travel through a medium. It is defined as the ratio of the pressure of the sound wave to the particle velocity within the medium.

A medium's acoustic impedance is influenced by its density and the speed of sound in that medium. Higher acoustic impedance means that the medium presents more resistance to the sound waves, which can affect how sound propagates, reflects, or is absorbed. This property is crucial in various applications, including audio engineering, architectural acoustics, and medical ultrasound, as it dictates how well sound can transmit through different materials.

In contrast, wave speed refers to the speed at which sound travels through a medium but does not quantitate obstruction. Sound intensity measures the power per unit area carried by a sound wave, while sound pressure describes the local pressure variation from the ambient atmospheric pressure caused by the sound wave. These concepts are related to sound but do not specifically address the obstructive capacity of the medium like acoustic impedance does.