SoundGeek

SoundGeek writes a cleaned copy of a recording beside the original. Steady background noise is reduced, mains hum is found and removed at whichever of 50 Hz or 60 Hz is actually present, rumble is taken out, and loudness is evened to a target measured to ITU-R BS.1770.

Three strengths of cleanup are offered, from filtering that returns the file at its original sample rate to a speech model that is far stronger and returns 16 kHz mono. The app is plain about what each one costs you.

Everything happens on the machine, the original is only ever read and never altered, and the app reports what it changed in numbers rather than asking you to take its word for it. No account, no adverts and no per minute charge.

Free and open source under GPL-3.0. The .NET 8 runtime is bundled, so there is nothing to install first.