Free Music Software: Christian Budde’s Noise Reduction is a free VST plugin for Windows.

Budde notes:

The Noise Reduction plugin is based on a spectral gate to filter out unwanted noise in the frequency domain. The gate is based on the lightweight dynamic series and features a soft knee and customizable attack and release times.

Originally this plugin was planned for the KVR’09 developer contest, but in the end I missed the deadline by one day and thus I had to use another plugin for my entry.

Features:

• Highly customisable spectral noise gate
• Continous and consistent characteristic
• Fully adjustable soft knee in dB (as margin below the threshold)
• Several exotic window functions available
• Low CPU usage
• Different FFT sizes
• Manual included
• Open source (as part of the Delphi ASIO & VST Project)

Download it from Budde’s site.