Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
Spectro - Spectro is a freeware audio file analyzer for windows.
Tenacity - Tenacity is an easy-to-use, privacy-friendly, FLOSS, cross-platform multi-track audio editor/recorder for Windows, macOS, Linux and other operating systems.
Friture - Friture is a program designed to analyze audio input in real-time.
AudioMass - A full-featured web based audio editor 🎶
Lossless Audio Checker - A utility to check whether an audio file is truly lossless or not.