Grey noise: Difference between revisions
m Tagging using AWB (10467) |
Some cleanup and better explanations. Clarified that *the* grey noise doesn't exist. This article doesn't need that much attention because the actual work is done in the equal-loudness curves article. |
||
| Line 1: | Line 1: | ||
{{Refimprove|date=September 2014}} |
|||
{{Colors of noise}} |
{{Colors of noise}} |
||
| Line 5: | Line 4: | ||
[[Image:Gray noise spectrum.svg|thumb|left|Grey noise spectrum]] |
[[Image:Gray noise spectrum.svg|thumb|left|Grey noise spectrum]] |
||
This is in contrast to [[white noise]], noise which |
This is in contrast to [[white noise]], noise which has the same energy at all frequencies but is not perceived as equally loud to [[psychoacoustics]]. ''See [[Colors of noise]]''. |
||
Note that humans perceive noise loudness based on amount of energy per octave, not amount of energy per hertz, so pink noise is closer to “equally loud at all frequencies” than white noise is.<ref>http://www.acousticfields.com/white-noise-definition-vs-pink-noise/</ref> Similarly, a grey noise weighting curve must produce a psychoacoustically flat curve on a plot of energy per octave, not on a plot of energy per Hz (like [[Fast Fourier Transform]]). |
|||
Since equal-loudness curves depend not only on the individual but also on the volume at which the noise is played back, there is no one true grey noise.<ref>http://www.audiocheck.net/testtones_greynoise.php</ref> A mathematically simpler and clearly defined approximation of an equal-loudness noise is [[pink noise]] which creates an equal amount of energy per octave, not per hertz (i. e. a logarithmic instead of a linear behavior), so pink noise is closer to “equally loud at all frequencies” than white noise is.<ref>http://www.acousticfields.com/white-noise-definition-vs-pink-noise/</ref> |
|||
{{Listen|filename=Gray noise.ogg|title=10 seconds of grey noise|description=}} |
{{Listen|filename=Gray noise.ogg|title=10 seconds of grey noise|description=}} |
||
Revision as of 14:03, 14 August 2015
| Colors of noise |
|---|
Grey noise is random noise subjected to a psychoacoustic equal loudness curve (such as an inverted A-weighting curve) over a given range of frequencies, giving the listener the perception that it is equally loud at all frequencies.
This is in contrast to white noise, noise which has the same energy at all frequencies but is not perceived as equally loud to psychoacoustics. See Colors of noise.
Since equal-loudness curves depend not only on the individual but also on the volume at which the noise is played back, there is no one true grey noise.[1] A mathematically simpler and clearly defined approximation of an equal-loudness noise is pink noise which creates an equal amount of energy per octave, not per hertz (i. e. a logarithmic instead of a linear behavior), so pink noise is closer to “equally loud at all frequencies” than white noise is.[2]
References
 | This article related to telecommunications is a stub. You can help Wikipedia by expanding it. |