White noise JNDLs are level-independent above 40 dB but narrow-band are not

Evidence

Changing from tones to broad-band noises affects the dependence of JNDL on sound pressure level. As indicated in Fig. 7.7, the level dependence disappears almost completely for white noise in the sound pressure level range above 40 dB. If white noise is limited by a low-pass filter so that the upper slope of masking with its level dependence can be seen, the level dependence becomes noticeable again, as indicated by open circles connected by broken lines. The size of JNDL around 60 dB sound pressure level is about 0.5 dB for most broad-band noises. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1049

Categorization

Category: Factual Claims

• QUESTION: Why does low-pass filtering of white noise restore level dependence? The connection to masking slopes is mentioned but not elaborated here.

Related

• Level discrimination for broadband noise is level-independent above 40 dB sound pressure (similarity 0.94)
• White noise masking of tones is linear but frequency-dependent above 500 Hz (similarity 0.83)
• JNDL level dependence unifies across frequency when scaled to loudness level (similarity 0.82)
• Level discrimination thresholds grow steeply near hearing threshold (similarity 0.81)
• Raising low-pass noise level measurably raises its perceived pitch (similarity 0.81)
• Masking by bandlimited noise depends only on masker energy within the critical band. (similarity 0.81)
• Partial masking of a tone by background noise diminishes as tone level rises (similarity 0.80)
• Just-noticeable changes are tenfold worse at masked threshold then normalize 20 dB above (similarity 0.80)
• Only tones exceeding a level-dependent masked threshold are audible in noise (similarity 0.80)
• Masked threshold of a tone by white noise is computable from critical-band level (similarity 0.80)
• Keeping total level constant while widening bandwidth requires lowering spectral density (similarity 0.80)
• Low-pass noise cutoff discrimination degrades with level while high-pass cutoff does not (similarity 0.79)
• A narrow noise band can mask signals multiple octaves away at high stimulus levels. (similarity 0.79)
• Noise loudness is level-independent until bandwidth exceeds the critical bandwidth. (similarity 0.79)
• Noise bandwidth below the critical band does not raise masked threshold. (similarity 0.79)