Spectro - Spectro is a freeware audio file analyzer for windows.
Lossless Audio Checker - A utility to check whether an audio file is truly lossless or not.
REW - REW is free room acoustics analysis software for measuring and analysing room and loudspeaker...
S_TOOLS-STx - Digital Signal Processing (DSP), STx
Spek - Spek helps to analyse your audio files by showing their spectrogram.
sndpeek - a real-time audio visualization tool (animated, 3D)