Room Tone Generator!
A free VST and AU plug-in by Jay Rose, CAS
As described in Producing Great Sound for Film and Video

screenshot
Drop about a half-second of clean roomtone into this utility.
It'll use your source as a model, and generate matching random roomtone.
Yes, random! It won't sound looped, no matter how much you need!

This plug-in requires the free open-source SonicBirth utility from SourceForge. It runs in Macs only, but can be hosted in any software that accepts AU or VST.

For full details and instructions, see the ReadMe file included with each of the downloads below.

 

Downloads

 

This is free and open-source.

Plug-in © 2014 and contributed by Jay Rose.
SonicBirth © 2004-2007 and contributed by Antoine Missout.
You may modify and/or distribute, if you maintain the free and open-source status and include credit for the above contributions with your version.
Want to write a Windows version? We'd love to include it here.