Roughness is proportional to the product of modulation frequency and masking depth

Evidence

Roughness (Daniel and Weber, 1997; Fastl and Zwicker, 2007) is a psychoacoustic quantity which is caused by relatively fast amplitude modulations (15–300 Hz) that take place for stimuli within the range of a critical band. For example, narrowband noise always sounds slightly rough, since there are random amplitude fluctuations in it. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1237 (#expands, via linked claim)

If the level of sound fluctuates relatively slowly over a certain range of rates, between about 1 Hz and 16 Hz, a significant fluctuation strength may be perceived. When the modulation rate far exceeds 16 Hz, our hearing is unable to follow the level of sound, and the sound is perceived as rough, associated with the psychoacoustic quantity roughness. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1217 (#expands, via linked claim)

Categorization

• XREF: connects to: Low modulation frequencies produce fluctuation sensation while higher ones produce roughness — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1381; Roughness-versus-modulation-frequency curves shift shape across carrier frequencies; Roughness grows faster with modulation depth for tones than for noise (+3 more)

Related

• Roughness grows faster with modulation depth for tones than for noise (similarity 0.95)
• Periodic modulation enhances perceived fluctuation strength beyond random noise (similarity 0.93)
• Low modulation frequencies produce fluctuation sensation while higher ones produce roughness (similarity 0.93)
• Frequency modulation produces up to six times the roughness of amplitude modulation (similarity 0.93)
• Fast amplitude modulations within a critical band produce roughness perception (similarity 0.92)
• Modulation frequency determines whether sound is heard as fluctuation, roughness, or multiple tones (similarity 0.91)
• Roughness reflects rate of change, so fast modulation roughens while slow change does not (similarity 0.90)
• Roughness depends on modulation degree or FM index plus modulation rate (similarity 0.90)
• Fluctuation strength depends on the critical-band interval a frequency sweep traverses (similarity 0.89)
• Frequency-modulated tones lose fluctuation strength above 1 kHz centre frequency (similarity 0.88)
• Above 250 Hz modulation, frequency-modulated sounds behave as steady state. (similarity 0.88)
• Wideband frequency modulation produces far more roughness than amplitude modulation (similarity 0.87)
• Roughness from harmonics requires fundamental frequencies below 100 Hz (similarity 0.87)
• Slow sound-level changes are heard as fluctuation and fast ones as roughness (similarity 0.87)
• Amplitude-modulated tones produce three distinct sensations depending on modulation frequency (similarity 0.86)

Broader Connections

• Roughness grows faster with modulation depth for tones than for noise #qualifies (0.85)
• Fast amplitude modulations within a critical band produce roughness perception #expands (0.80) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1237
• Modulation frequency determines whether sound is heard as fluctuation, roughness, or multiple tones #expands (0.80) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1217
• Frequency separation between two tones systematically shifts fusion, roughness, then resolution #expands (0.70)