Weber’s law states JND is a constant fraction of stimulus magnitude

Evidence

Weber, however, was the first to develop a systematic method of inquiry evaluating the relationship between the magnitude of physical stimuli and their associated sensation or perception. Although his work was conducted primarily in the areas of touch and vision, in 1834 he discovered what is now known as Weber’s law (see Chapter 4). He noticed that, for pressure on the skin, the JND in weight was about 1/30th of the weight. Further evaluation has demonstrated that this principle has evidence from many other sensory modalities, including hearing and vision. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 59

Categorization

• DEFINE: Weber’s law defined: JND in weight is about 1/30th of the weight, generalizing across modalities.
• XREF: Connects to the reader’s auditory perception understanding — Weber’s law is foundational for later frequency/level discrimination results.