Fletcher’s equal-power masking assumption is demonstrably false

Evidence

Since all the methods, except that using Fletcher’s assumption, lead to similar values of the critical bandwidth, it seems reasonable to accept the latter estimates and conclude that the equal power assumption is wrong. It will be shown in Chap. 7 that threshold is reached when the signal power is one half (at low frequencies) to one quarter (at higher frequencies) that of the masker. Introducing these ratios, masking of a tone by noise (Fletcher’s method) leads to the same critical bandwidth as found using the five methods described. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 912

Categorization

Category: Contrarian or Surprising Claims

• DEFINE: Explains why the classic equal-power assumption fails and what ratios actually hold.

Related

• Equal-power masking assumption is wrong and only partly power detection holds (similarity 0.98)
• Fletcher’s equal-power assumption implies a low-frequency critical band near 50 Hz (similarity 0.90)
• Fletcher assumed tone audibility requires power match within a critical band (similarity 0.88)
• There is a critical bandwidth beyond which adding noise power no longer increases masking (similarity 0.85)
• Noise bandwidth below the critical band does not raise masked threshold. (similarity 0.84)
• Two simultaneous maskers partition the spectrum where each dominates (similarity 0.82)
• Equal-level narrow-band maskers mask less at higher centre frequencies (similarity 0.82)
• Critical bandwidth stays constant with masker level up to about 50 dB. (similarity 0.81)
• Masking effectiveness depends only on masker power inside the critical band. (similarity 0.81)
• Fletcher originated threshold measurement, loudness relations, and masking models (similarity 0.81)
• The band-widening paradigm measures signal threshold while varying masker bandwidth (similarity 0.81)
• Masked threshold rises once noise bandwidth exceeds the critical bandwidth (similarity 0.81)
• Pure-tone versus noise masking differences depend on masker frequency (similarity 0.81)
• Masker effectiveness is determined solely by power falling within one auditory filter. (similarity 0.80)
• Beyond threshold, masker and signal levels rise one-for-one in decibels (similarity 0.80)