Frequency discrimination stems from steep filter slopes plus 1 dB level sensitivity

Evidence

Since the lower slope is independent of critical-band rate, the model leads to direct proportionality between just-noticeable frequency variation, 2.1/, and the width of the critical band. The factor between the two should be 27, the constant lower slope in dB/ .1/G . This value corresponds quite well to the data outlined in Fig. 6.10. There, a factor of 25 is marked between the two values. Our model therefore assumes that the high sensitivity of our hearing system for variations in frequency is not established by the use of specialized systems that react to frequency changes. Rather, the steep slopes of the frequency selectivity of our hearing system are the reason for the high sensitivity to frequency changes. This sensitivity is based on our hearing system’s ability to indicate changes in excitation level that are of the size of only 1 dB. It seems that our hearing system is using this sensitivity for level changes together with its frequency selectivity to reach the high sensitivity for frequency variations. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1143

Categorization

• DEFINE: Clarifies that auditory frequency sensitivity is derived from excitation-level slopes, not dedicated frequency-change mechanisms.
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1143
• XREF: connects to: Frequency-modulation detection relies on the steep lower excitation slope at 27 dB per Bark; Human pitch discrimination far exceeds the ear’s filter resolution — David Howard, Jamie Angus, coustics and Psychoacoustics, 880; Brief tone durations severely impair frequency discrimination — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3313 (+3 more)

Broader Connections

• Human pitch discrimination far exceeds the ear’s filter resolution #contradicts (0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 880
• Brief tone durations severely impair frequency discrimination #qualifies (0.75) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3313