Roughness (acoustics)

from Wikipedia, the free encyclopedia
Example: Two sine tones 1000 Hz and 1070 Hz (at 60 dB = 1 Asper) Listening to h '' and c '' 'at the same time ? / i 1000Hz alone. The sound h '' ? / iAudio file / audio sample
Audio file / audio sample

The roughness is a psychoacoustic perception variable that is perceived especially in frequency and amplitude modulated sounds . Especially sounds with modulation frequencies between about 30 and 300  Hz cause roughness, z. B. the creaking or humming sound of a flying beetle or an electric or piston motor .

The roughness can be reproduced using a complex calculation process. A process developed for this simulates the perception of realistic noises quite well.

Unit of measurement

The roughness of a noise ( sound ) is determined by listening tests and is given in the unit of measurement asper . An Asper corresponds to the roughness of a 100% amplitude-modulated 1 kHz sinusoidal tone at 70 Hz at a sound pressure level of 60  dB .

Roughness of chords


In pure tuning, the pure third (frequency ratio 5: 4, 386 cents) does not hear any beat in the overtones.

The "sharpened" third in equal steps (400 cents) is perceived as rough because the overtones "rub".

A major cadence Purely:

See: Intonation (music)

See also

Individual evidence

  1. Gerhard Müller, Michael Möser (ed.): Pocket book of technical acoustics. 3rd, expanded and revised edition, 2003, p. 88. (Online at Google Books)
  2. Ernst Terhardt: Acoustic Communication. Basics with audio examples. 1st edition, 1998, Springer-Verlag, ISBN 978-3-540-63408-9 , p. 293. (Online at Google Books)
  3. R. Sottek: Aurally compatible roughness calculation. ( PDF , 3.1 MB).