Magnitude estimation of loudness yields only relative, not absolute, values.

Evidence

For example, a sound twice as loud would be assigned a value of 2 and a sound half as loud would be assigned a value of .5. Using this approach, the numbers resulting from magnitude estimation only have meaning in the context of each other and in the context of the number assigned to the reference. If a listener assigned a value of 2 in a magnitude estimation experiment, we could determine that 2 is double that of 1, but the 2 by itself is meaningless. A sound with a loudness of two sones is twice as loud as a sound with a loudness of one sone, but we do not know the absolute loudness of either of those sounds. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 712

Categorization

• DEFINE: Clarifies how the sone scale works as a ratio/relative measure rather than an absolute one.