Low modulation frequencies produce fluctuation sensation while higher ones produce roughness

Evidence

Modulated sounds elicit two different kinds of hearing sensations: at low modulation frequencies up to a modulation frequency of about 20 Hz, the hearing sensation of fluctuation strength is produced. At higher modulation frequencies, the hearing sensation of roughness, discussed in detail in Chap. 11, occurs. For modulation frequencies around 20 Hz, there is a transition between the hearing sensation of fluctuation strength and that of roughness. It is a smooth transition rather than a strong border that exists between the two sensations. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1381

Categorization

• DEFINE: Distinguishes fluctuation strength from roughness by modulation frequency, clarifying two psychoacoustic constructs divided near 20 Hz.
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1381
• XREF: connects to: Modulation frequency determines whether sound is heard as fluctuation, roughness, or multiple tones — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1217; Fast amplitude modulations within a critical band produce roughness perception — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1237; Roughness is proportional to the product of modulation frequency and masking depth (+3 more)

Broader Connections

• Modulation frequency determines whether sound is heard as fluctuation, roughness, or multiple tones #corroborates (0.95) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1217
• Fast amplitude modulations within a critical band produce roughness perception #expands (0.85) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1237
• Roughness is proportional to the product of modulation frequency and masking depth #expands (0.80)
• Perception of two tones progresses from beats to roughness to smoothness #expands (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 575