Image:DescenteInfinie.ogg

From Wikipedia, the free encyclopedia

DescenteInfinie.ogg‎ (Ogg Vorbis sound file, length 1m6s, 42kbps)

Wikimedia Commons logo This is a file from the Wikimedia Commons. The description on its description page there is shown below.
Commons is a freely licensed media file repository. You can help.
Featured sound star This is a featured sound file, which means that members of the community have identified it as one of the finest sound files on the English Wikipedia, adding significantly to its accompanying article. If you have a different recording of similar quality, be sure to upload it using the proper free license tag, add it to a relevant article, and nominate it.

Contents

[edit] Summary

[edit] Comments

  • English : This is a Shepard-Risset glissando. I programmed this acoustic illusion in Java one year ago. Unfortunately, the source code is lost today because of a computer crash, but the equation is below.
  • Français : Ceci est un glissando de Shepard-Risset. J'ai programmé cette illusion acoustique en Java il y a un an. Le code source est malheureusement perdu (crash de mon ordinateur), mais l'équation est présentée ci-dessous.
  • Español : Este sonido es un Shepard-Risset glissando. Programe esta ilusion acustica hace un año en Java. Desafortunadamente, el codigo se perdio al estropearseme el ordenador pero la ecuacion esta abajo.

[edit] Equation

\,s T-periodic on \mathbb{R}

\forall t \in \left [0, T \right [

\,s(t) = a(t) \sin \left ( \omega(t) t \right ) + a(t + T) \sin \left (2 \omega(t) t \right )

with \begin{cases} \begin{array}{lcl} a(t) & = & A_0 \cfrac{1 + \cos \pi \frac{t}{T}}{4} \\ \omega(t) & = & 2 \pi F_0 \cfrac{1}{2^\frac{t}{T}} \\ F_0 & = & 220\,Hz \\ T & = & 20\,s \\ A_0 & = & 0.7 \end{array} \end{cases}

The same signal is added on a minor chord, on several octaves, see details on my web site.

--Gloumouth1 01:39, 10 December 2005 (UTC)

[edit] Loop

If you want to have a loop, as T = 20 s, you can crop this sound exactly from 20 s to 40 s.

[edit] Another idea

If I (or you) have time, one day, another function which could be programmed and recorded...

\forall t \in \mathbb{R} \quad s (t) = \sum_{k=-\infty}^\infty a_k(t) \sin \left ( \omega_k(t) t \right )

with \begin{cases} a_k(t) = A_0 e^{-\cfrac{ \left ( k-\frac{t}{T} \right ) ^2}{\sigma^2}} \\ \omega_k(t) = 2 \pi F_0 2^{k - \frac{t}{T}} \\ A_0, F_0, T, \sigma \, constants \end{cases}

--Gloumouth1 17:04, 5 March 2007 (UTC)

[edit] Licensing

This illustration was made by Gloumouth1.

Please credit this : Gloumouth1, http://gloumouth1.free.fr

An email to gloumouth1 at laposte.net would be appreciated too.
I, the copyright holder of this work, hereby publish it under the following licenses:
GNU head Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation license, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation license".

Aragonés | العربية | Asturianu | Български | বাংলা | ইমার ঠার/বিষ্ণুপ্রিয়া মণিপুরী | Brezhoneg | Bosanski | Català | Cebuano | Česky | Dansk | Deutsch | Ελληνικά | English | Esperanto | Español | Eesti | Euskara | فارسی | Suomi | Français | Gaeilge | Galego | עברית | Hrvatski | Magyar | Bahasa Indonesia | Ido | Íslenska | Italiano | 日本語 | ქართული | ភាសាខ្មែរ | 한국어 | Kurdî / كوردی | Latina | Lëtzebuergesch | Lietuvių | Bahasa Melayu | Nnapulitano | Nederlands | ‪Norsk (nynorsk)‬ | ‪Norsk (bokmål)‬ | Occitan | Polski | Português | Română | Русский | Slovenčina | Slovenščina | Shqip | Српски / Srpski | Svenska | తెలుగు | ไทย | Türkçe | Українська | اردو | Tiếng Việt | Volapük | Yorùbá | ‪中文(中国大陆)‬ | ‪中文(台灣)‬ | +/-
Creative Commons License
Creative Commons Attribution iconCreative Commons Share Alike icon		 This file is licensed under the Creative Commons Attribution ShareAlike 2.5 License. In short: you are free to share and make derivative works of the file under the conditions that you appropriately attribute it, and that you distribute it only under a license identical to this one. Official license
You may select the license of your choice.

josh

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeDimensionsUserComment
current21:40, 9 December 20051m6s (336 KB)Gloumouth1 (en:Shepard tone I programmed it in en:Java one year ago. --Gloumouth1 Category:Synthetic sound)