Audacity is a cross-platform multitrack audio editor. It allows you to record sounds directly or to import Ogg, WAV, AIFF, AU, IRCAM, or MP3 files. It features a few simple effects, all of the editing features you should need, and unlimited undo. The audio I/O uses PortAudio, which fully supports OSS, Mac OS X CoreAudio, and Windows WMME, and can be compiled with support for ALSA and Jack.
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.
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.
jMax is a visual programming environment for building interactive real-time musical and multimedia applications by allowing the user to interactively design dataflow circuits. The basic data types that can go through are integers, symbols, lists, etc. It is an event-driven system and has been used for MIDI processing. A second part of the system (DSP) allows a continuous signal to flow through a circuit, which is most useful for PCM sound (ie. microphone, sound files, etc.). The system is extensible by using shared libraries, you may add data processor types, data types, GUI elements, device types, and more. Data processors may also be designed as circuits and reused.
Transcribe! is an assistant for working out a piece of music from a recording. It offers many features aimed at making the transcription job smoother and easier, including the ability to slow down the music without changing its pitch, and to analyse chords and show you what notes are present.
somaplayer is music player for MP3, Ogg, wav, audio CDs, MP3 streams, and Ogg streams. It is able to use the appropriate sound drivers or demons or to stream directly to an Icecast server (Icecast2 or SHOUTcast) or to encode in MP3 and Ogg Vorbis. It also acts as a sound daemon that is able to accept connections from other somaplayers or any other sound player (xmms, mpg123, and others) thanks to a special wrapper.