Intensity discrimination improves with level for tones, violating Weber’s law

Evidence

Weber’s law did not hold for tones. In fact, the JND, when expressed as a proportion of the intensity of the stimulus, decreased with increasing intensity across the audible range. This phenomenon is called the near miss to Weber’s law. Note that we observe this result only for tones and not noise at levels greater than 20 dB SL. • The Weber fraction was not dependent on frequency. The overall sensitivity for intensity discrimination did not vary with frequency, and the slope of the near miss to Weber’s law was constant across the frequencies up to about 10 kHz. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 824

Categorization

• DEFINE: Introduces and defines the ‘near miss to Weber’s law’ — a core concept in loudness perception.
• QUESTION: Why does the near miss hold for tones but not for noise above 20 dB SL? The chapter gestures at multi-frequency integration — worth chasing the mechanism further.