DFasma is free open-source software which is used to compare audio files in time and frequency. The comparison is first visual, using wavforms and spectra. It is also possible to listen to time-frequency segments in order to allow perceptual comparison. It is basically dedicated to analysis. Even though there are basic functionalities to align the signals in time and amplitude, this software does not aim to be an audio editor.
Can load about 25 different audio formats (thanks to libsndfile or libsox).
Shows spectrogram, amplitude, phase spectra and group delay.
Can play a filtered sound given a selected frequency band.
Rectification of the spectrogram tilt (cepstral lifting).
Can create and edit segmentation files.
Can create and edit fundamental frequency (F0) files (thanks to REAPER).
Baudline is a time-frequency browser designed for scientific visualization of the spectral domain. Signal analysis is performed by Fourier, correlation, and raster transforms that create colorful spectrograms with vibrant detail. Conduct test and measurement experiments with the built in function generator, or play back audio files with a multitude of effects and filters. The baudline signal analyzer combines fast digital signal processing, versatile high speed displays, and continuous capture tools for hunting down and studying elusive signal characteristics.
Tau Analyzer is a free program, which can help you to distinguish with reasonable accuracy the original studio-based CDs from poor quality fakes, that have been “reconstructed” using a lossy audio source, such as mp3. Using this program you can check the authenticity of your purchased or borrowed music CDs.
Tau Analyzer features an intuitive user interface, allowing users to work directly with audio CDs, and has some additional functions such as spectrum and frequency analyzers, ATIP and ISRC data readers, etc.
Spectro is a freeware audio file analyzer for Windows. Currently capable of reading FLAC, APE, MP3 and WAV files. Spectro lets you view vital data about compressed audio files and creates a spectrogram of the wave data. This allows you to quickly and easily spot quality issues with a file and also look for transcodes.