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.
eXtace is a visual sound display/analysis program. It requires Esound (esd) for its audio source. It includes various fast fourier transforms of the audio data in realtime. Its displays include a 3D wireframe flying landscape, a 3D textured flying landscape, a 16-256 channel graphic EQ, three types of scopes, a 3D "spike" flying landscape, and two forms of spectragrams. The 3D traces can be picked up, manipulated, and displayed at nearly any angle. eXtace also features a 3D direction control widget for controlling the angle and speed at which the trace runs away and a gradient/colormap editor for changing the colormap to suit your needs. No OpenGL is required.
HASAS (HydroAcoustic Signal Analysis System) is a modular system for passive sonar signal analysis. It can be used for biological research or surveillance, for example. The soundcard is used as input device, and it currently includes all the very basic functionality; beamformed audio, direction finding, level histogram, LOFAR/DEMON (narrowband spectrogram), wideband spectrogram, and raw audio.
The Snack sound extension adds commands for sound play/record and sound visualization, e.g. waveforms and spectrograms. It supports in- memory sound objects, file based audio, streaming audio, WAV, AU, AIFF, and MP3 file formats, synchronous and asynchronous playback. The visualization canvas item types update in real-time and can output postscript. New commands and file formats can be added using the Snack C-API.
The aim of auch (audio-checker) is to visualize music. It takes audio from the microphone and uses it to simulate an elastic and vibrating surface (chladni-tranform) or the reflection of such a surface (makyoh-transform). Many more transforms can be activated by unlocking the interactive shell.
MARF is a general cross-platform framework with a collection of algorithms for audio (voice, speech, and sound) and natural language text analysis and recognition, along with sample applications (identification, NLP, etc.) of its use. MARF can run distributed over the network (CORBA, Java RMI, and Java XML-RPC Web Services) and may act as a library in applications or be used as a source for learning and extension.
WaveSurfer is a sound visualization/manipulation tool for novice and advanced users, with a simple and intuitive user interface. It can be adapted to different tasks, such as speech research and education, speech/sound analysis, and sound annotation/transcription. You can also make more advanced/specialized applications by extending it with custom plugins or embed WaveSurfer components in other applications. Its flexible interface handles many different file formats, and it runs on many flavors of Windows and Unix. It also supports encoding and Unicode with unlimited file size, and more.