Download of ToneLib-NoiseReducer 1.2.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The actual developer of this free software for Mac is ToneLib. The software is included in Audio & Video Tools.
From the developer:
ToneLib NoiseReducer is a powerful, yet simple plugin that modulates a two-unit noise reduction rack effect so you can easily remove all the unwanted noises from your mix. Designed to be straightforward and easy to use, TL NoiseReducer adapts perfectly to practically every specific task you aimed on. You won't find anything superfluous in the controls of this plugin.
You may want to check out more Mac applications, such as SoundByte, Lounge Lizard Session or microKORG SoundEditor, which might be related to ToneLib-NoiseReducer.