Image:Gray noise spectrum.png

[edit] Summary

Spectrum analysis of uncompressed source for 10 seconds of gray noise ^{file— play in browser}. Note the logarithmic frequency scale.

The analysis was done using Audacity, and plotting with gnuplot. Transparency was touched up in GIMP to make the graph background pure white.

[edit] Instructions

Obtain the frequency analysis from Audacity, set the maximum number of windows, and use a Hamming window. The following script was used to generate the image:

set terminal png transparent font "/usr/share/fonts/truetype/ttf-bitstream-vera/Vera.ttf" size 800,600 enhanced
set output "gray_noise_spectrum.png"

# this seems to fix the trailers on the TTF font for the x-label
set bmargin 4

# enable grid
set grid
set grid mxtics

# set up x-axis
set logscale x 10
set xrange [100:22000]
set xlabel "Frequency (Hz)"
set xtics border nomirror

# set up y-axis
set yrange [-40:0]
set ylabel "Intensity (dB)"
set ytics border nomirror

# again to deal with bad bboxes on the TTF...
set key height 1 box

# plot the output from Audacity
plot "gray_noise.txt" title "Gray Noise" with filledcurves x1 3

[edit] Licensing

I, the copyright holder of this work, hereby release it into the public domain. This applies worldwide. In case this is not legally possible: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law. Afrikaans | Alemannisch | Aragonés | العربية | Asturianu | Български | Català | Česky | Cymraeg | Dansk | Deutsch | Eʋegbe | Ελληνικά | English | Español | Esperanto | Euskara | Estremeñu | فارسی | Français | Galego | 한국어 | हिन्दी | Hrvatski | Ido | Bahasa Indonesia | Íslenska | Italiano | עברית | Kurdî / كوردی | Latina | Lietuvių | Latviešu | Magyar | Македонски | Bahasa Melayu | Nederlands | ‪Norsk (bokmål)‬ | ‪Norsk (nynorsk)‬ | 日本語 | Polski | Português | Ripoarisch | Română | Русский | Shqip | Slovenčina | Slovenščina | Српски / Srpski | Svenska | ไทย | Tagalog | Türkçe | Українська | Tiếng Việt | Walon | ‪中文(简体)‬ | ‪中文(繁體)‬ | zh-yue-hant | +/-

• Colors of noise
• Grey noise