Narrow-band noise self-modulation masks external amplitude modulation

Evidence

Two pairs of amplitude modulated sounds (modulation frequency 4 Hz) are presented: The first sound in each pair is white noise, the second is narrowband noise with a bandwidth of 10 Hz. The first pair has a degree of modulation of 50%, the second pair only 7%. In the first pair both modulations are clearly audible. However, due to the strong self modulation of the narrowband noise with about 6.4 Hz effective modulation frequency, the amplitude modulation of the narrow-band noise is not audible in the second sound pair. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3302

Categorization

• DEFINE: Introduces the concept of self-modulation in narrowband noise — its intrinsic fluctuation acts like its own amplitude modulation.
• XREF: Connects to noise fluctuation and modulation perception literature; self-modulation of narrowband noise is a classic sonar/bioacoustics phenomenon. — connects to: Intrinsic noise amplitude fluctuation masks detection of imposed amplitude modulation; Narrow-band noise self-modulates at 0.64 times its bandwidth — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3336; Modulation in off-frequency channels can suppress on-frequency modulation processing — Dijk, Pim van, Physiology, Psychoacoustics and…, 3473 (+3 more)
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3302

Broader Connections

• Modulation in off-frequency channels can suppress on-frequency modulation processing #corroborates (0.90) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3473
• Modulation-frequency-specific disruption captures interferer masking effects better than energy models #expands (0.82)
• Energy-based models of modulation filterbanks fail to predict interferer effects on detection #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3494
• Narrowband noise at a given frequency masks nearby tones much more than distant ones #exemplifies (0.75)