JND for frequency changes is level-independent while level JNDs shrink with level

Evidence

A typical example is given in Fig. 7.4. Two sets of data with a I-kHz tone, one for level changes (left) and another for frequency changes (right), are shown as a function of level. The results produced for level variations (measured as just-noticeable amplitude modulation and indicated by the open circles) decrease from almost 2 dB to about 0.7 dB between 30 and 70 dB sound pressure level. The results for just-noticeable level differences (dots) decrease as a function of level from about 0.7 dB to about 0.3 dB. There is a factor of about 2.5 between the two curves. However, the dependence of just-noticeable amplitude modulation on level remains similar to that for the just-noticeable level difference. The data produced for justnoticeable frequency modulation (open circles in the right part in Fig. 7.4) show no dependence on level. The same is true for the just-noticeable frequency difference (dots) although the data are about a factor of 3 lower than for frequency modulation. The interquartile ranges indicate very clearly that the two sets of data do not overlap, i.e. just-noticeable frequency modulation and just-noticeable frequency difference not only lead to different results but may also be produced by different signal processing in our hearing system. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1034

Categorization

Category: Factual Claims

• XREF: The level-independent frequency discrimination contrasts with amplitude/level discrimination, echoing the place-vs-rate coding distinction from Chaps. 5 and 6.

Related

• Just-noticeable level variations always exceed just-noticeable level differences (similarity 0.87)
• Detecting level variation is about 2.5 times harder than detecting level difference (similarity 0.87)
• Level discrimination thresholds grow steeply near hearing threshold (similarity 0.86)
• JNDL level dependence unifies across frequency when scaled to loudness level (similarity 0.85)
• Just-noticeable frequency increments are constant along critical-band rate but rise as pitch strength weakens (similarity 0.84)
• Frequency discrimination depends on pitch strength and worsens as pitch strength falls (similarity 0.83)
• Pitch discrimination is best near 500 Hz and degrades at both extremes (similarity 0.83)
• Humans can typically discriminate level differences of 1 to 2 dB (similarity 0.83)
• The ear’s just-noticeable amplitude difference depends on signal type, level, and frequency (similarity 0.82)
• Short tone duration inflates JNDF, and level affects low-pass but not high-pass cutoff discrimination. (similarity 0.82)
• Frequency modulation detection is level-independent but thrice frequency-difference detection (similarity 0.82)
• Amplitude discrimination depends on relative loudness increment, not absolute change (similarity 0.82)
• Interval-adjustment precision declines sharply at 10 kHz (similarity 0.81)
• Just-noticeable amplitude modulation drops steeply as tone level rises (similarity 0.81)
• Frequency discrimination thresholds rise dramatically from 500 Hz to 5000 Hz (similarity 0.81)

Broader Connections

• Interval-adjustment precision declines sharply at 10 kHz #complicates (0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5408