Increasing intensity improves frequency discrimination, much more at low frequencies

Evidence

Better FDLs at higher intensities. Referring back to Figure 6–12, we observe that thresholds decreased as the intensity of the stimulus is increased. The task became easier at higher and higher stimulus levels. Notably, the change in the FDL with frequency was also much larger for the low frequencies than the high ones. For example, between the 10 and 80 dB levels, thresholds decreased by about a factor of 4 at 800 Hz but only by a factor of 1.25 at 8000 Hz. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1266

Categorization

• QUESTION: Why would intensity matter far more at 800 Hz than 8000 Hz? Possibly because low-frequency place cues depend on excitation spread that intensity sharpens.
• XREF: Pattern of larger level effects at low frequency echoes temporal-coding theories of pitch that operate mainly below a few kHz.