Aglaophone is a system of interconnectable modules for the recording, processing, and playback of real-time audio. It features a real-time spectrogram display for visualization along with a number of processing modules. Modules include filters, downsamplers, upsamplers, and quantizers. An MP3 comparison module allows interactive blind comparison of MP3 encoded audio with CD audio.
Brp-pacu is a cross-platform dual-channel FFT-based acoustic analysis tool to help engineers analyze live professional sound systems using the transfer function.
BWView offers multi-channel frequency analysis, originally designed to handle brainwave (EEG) files. Uses an unusual wavelet-based heterodyne-style analysis instead of the conventional FFT, allowing a much more natural frequency scale, and also much finer detail to be shown for the higher frequencies.
FANR is real-time audio note recognition (WAV to MIDI) software. The input is a wave signal captured trough the alsa pcm device and the output is a simple midi stream launched trough the ALSA sequencer.
Free Music Instrument Tuner features include an error history, volume history, wave-length shape, ALSA and JACK support.
FreeADSP is an (almost) realtime free cross-platform audio DSP applicaion heavily relying on external plugins for audio I/O, UI, effects (LADSPA, DSSI) and generic device interfacing (mice, joysticks, etc).
Japa (JACK and ALSA Perceptual Analyser), is a 'perceptual' or 'psychoacoustic' audio spectrum analyser. Possible uses include spectrum monitoring while mixing or mastering, evaluation of ambient noise, and (using pink noise), equalisation of PA systems.
LastWave is a signal processing oriented command language. It mainly consists of a powerful command line language with matlab-like syntax, which includes a high level object-oriented graphic language. It allows to deal with high-level structures such as signals, images, wavelet transforms, extrema representation, short time fourier transform,...
NASPRO (NASPRO Architecture for Sound PROcessing) is a powerful, reusable, modular, real-time capable, thread-safe, scalable, standard-agnostic, cross-platform framework for digital signal processing, especially focused on sound processing. Its main aim is to give audio application developers a full-featured, yet scalable, high-performance, and integrated tool to make use of virtually any external sound processing component via a single, fully transparent and platform-independent API.
ObjectProDSP is a tool for DSP design and analysis. It lets you define and edit a DSP network graphically.
Pd is a free real-time computer music software
package resembling Max.
Signal Applications To Audio Networks is a program that is used for various audio related signal processing tasks.
SigBrowser is a small tool to display large signals (up to 2 GB filesize / 1-6 channels / 16 bit integer).
SignalGen is a free (GPL) Linux (X windows GUI-based) utility that generates relatively low frequency signals with the use of a PC sound card. It is an entirely suitable replacement for a hardware signal generator if one doesn't require signals of a frequency higher than about 50 KHz.
Sonic Visualiser is an application for viewing and analysing the contents of music audio files. The aim of Sonic Visualiser is to be the program you reach for when you find a musical recording you want to study rather than simply hear. As well as a number of features designed to make exploring audio data as revealing and fun as possible, Sonic Visualiser also has powerful annotation capabilities to help you to describe what you find, and the ability to run automated annotation and analysis plugins in the new Vamp analysis plugin format.
Sound Ruler is a tool for acoustic analysis, graphing and teaching. It interactively recognizes and measures 35 temporal and spectral properties of each sound in a file. It also features several measurement, graphing and didactic modules.
Spectromatic is a program for generating spectrograms from audio files. Spectrograms are a form of simple time-frequency analysis which lets you see how the distribution of energy at different frequencies in an audio stream change over time. Spectromatic reads its input as mono or stereo 16-bit wave files, and writes the output image to an elongated PNG image (colour for stereo, grayscale for mono audio).
SSPLab AudioAnalyser (SAA) is a tool for analyzing audio signals in terms of its content. It is an opensource project released under GPL. It aims to: replicate human hearing system in terms of separating sources, recognizing speech and thus analyze the auditory scene, listen to the separated sources, and act as a osciloscope and specrum analyser for audio frequencies.
Tapiir is a simple and flexible audio effects processor, inspired on the classical magnetic tape delay systems used since the early days of electro-acoustic music composition. It provides a graphical user interface consisting of six delay lines, or "taps", which can introduce an almost arbitrarily big or small delay to their inputs and can be feed back to each other. A wide set of effects can be easily achieved by properly configuring and connecting the delay lines: complex echo patterns, resonances, filtering, etc. Delays, interconnections and gains can all be controlled in real time.
The Python audio processing suite
The Python audio processing suite is a module that contains a variety of convenience functions to process audio signals. It can be used to plot spectral analyses of a song across time and to quickly ascertain encoding quality, but the instrumental goal of this suite is to robustly identify duplicated songs, regardless of which album they were released in, encoding quality, or start time.
Vibtoolbox is a set of command line tools for analysis of vibration and acoustic test data. The interface design used for most of the tools in the package is the standard UNIX filter model. The tools take input on standard input and transform the input in some fashion, and then send the transformed input data to standard output. The filters are not interactive and are controlled by command line options. The tool set also defines ASCII and native binary database formats for storage of vibration and acoustic laboratory and flight test data.
wlog is a tool to analyze signals using wavelets. The wavelet tranformation has the property that it "divides"(or "decomposes") a signal in "smooth" S and a detailed (or "discontinuous") D part.