What sound parameter is determined only by the medium?

What sound parameter is determined only by the medium?

• A. Frequency
• B. Period
• C. Intensity
• D. Propagation speed

Answer: (D)

The sound parameter that is set by the medium itself is the propagation speed. This speed depends on how easily the medium can be compressed and how dense it is—stiffer, less dense materials transmit sound faster, while more compressible or denser media slow it down. In formula terms, the speed of sound is tied to the medium’s elastic properties and density, so changing the material changes the speed even if the sound source doesn’t change. The frequency is determined by the vibrating source and stays the same when the wave crosses into another medium (the wavelength adjusts to the new speed via the relation λ = v/f). The period is the inverse of frequency, so it’s also set by the source. Intensity depends on how much energy the source puts out and how the wave propagates through space and the medium, including attenuation, so it’s not fixed by the medium alone. So, the parameter determined only by the medium is the propagation speed.

The sound parameter that is set by the medium itself is the propagation speed. This speed depends on how easily the medium can be compressed and how dense it is—stiffer, less dense materials transmit sound faster, while more compressible or denser media slow it down. In formula terms, the speed of sound is tied to the medium’s elastic properties and density, so changing the material changes the speed even if the sound source doesn’t change.

The frequency is determined by the vibrating source and stays the same when the wave crosses into another medium (the wavelength adjusts to the new speed via the relation λ = v/f). The period is the inverse of frequency, so it’s also set by the source. Intensity depends on how much energy the source puts out and how the wave propagates through space and the medium, including attenuation, so it’s not fixed by the medium alone.

So, the parameter determined only by the medium is the propagation speed.