AUDINDEX - Real-time audio indexing tool
AUDINDEX is a Windows PC program for quickly adding an index to an audio file. AudIndex will allow you to replay the audio while recording the times (relative to the start of the audio) when keys are pressed.

BROWSE - Simple tool for browsing audio files
BROWSE is a program for browsing audio recordings. With BROWSE you can drag and drop audio files in a range of formats onto the display to see and hear their contents. BROWSE allows you to zoom, scroll and save the audio files to other formats.

CochSim - Cochlear Simulation teaching tool
CochSim is a dynamic simulation of the time and frequency analysis performed by the ear. Sound signals such as sinewaves, pulse trains, sawtooth waves and vowels can be fed into an auditory filterbank and the output monitored in a moving animated display. The program shows the vibration of the oval window and the basilar membrane, the haircell activity against filter frequency and time, and an average excitation pattern across the cochlea.

EFxHist - Fundamental Frequency Histograms
EFxHist is a program to analyse joint speech and laryngograph recordings. EFxHist locates each pitch period in the laryngograph waveform and produces statistical analyses including distributions of fundamental frequency, closed-quotient, jitter and shimmer.

Enhance - Speech Signal Enhancement
UCL Enhance is a program for the enhancement of the intelligibility of speech recordings. The program incorporates a number of standard techniques for manipulating the overall amplitude of the signal and for the removal of steady-state additive noise. However, the program is unusual in its ability to detect and enhance selective regions of the speech signal based on their phonetic properties.

ESECTION - Speech signal cross-sections
ESection is a free program for calculating and displaying spectral and other related analyses of sections of a speech signal. It can be used to demonstrate the different spectral properties of elements of speech. It can also calculate an LPC spectrum, autocorrelation and cepstrum analyses, and can display the signal as a waveform or as a spectrogram. It automatically finds formant and fundamental frequency values.

ESYNTH - Harmonic analysis/synthesis teaching tool
ESynth is a free program designed to explain the harmonic analysis and synthesis of signals. With ESynth you can create signals by adding together individual sinusoidal waveforms (sinewaves) and study the resulting waveform and spectrum. You can also perform an analysis of an input waveform, to see how a given sound can be represented in terms of a sum of sinewaves.

ESYSTEM - Signals and Systems teaching tool
ESYSTEM is a free program for experimenting with signals and systems. With ESYSTEM you can see the effect of simple systems on a range of simple signals. You can generate simple signals such as sinewaves, pulses, pulse trains, sawtooth and noise; you can pass them though systems such as an amplifier, a resonator, a low-pass, high-pass or band-pass filter, or a vocal tract model. You can observe the effect on the input and output waveforms and the input and output spectra. Now includes extensive tutorial!

FAROSON - The Auditory Lighthouse
FAROSON is a free program for displaying a real-time scrolling coloured pattern from speech sounds. The aim is to construct a pattern that reflects our subjective sensations of loudness, pitch and timbre. The program may be useful in teaching about the nature of sound sensation.

HEARLOSS - Hearing Impairment Demonstrator
HearLoss is a free interactive Windows PC program for demonstrating to normally hearing people the effects of hearing loss. With HearLoss you can replay speech, music and noise under a variety of loudness, filtering and masking conditions typical of hearing impairments. Best of all you can interactively change the settings and demonstrate their consequences.

PROREC - Speech Prompt & Record System
Prorec is a free Windows PC program for prompting speakers with lists of words or sentences and recording their speech back to disk. ProRec is suited to linguistics field workers wanting to use their laptop as an audio recording system.

RTGRAM - Real-time Spectrographic Display
RTGRAM is a free program for displaying a real-time scrolling speech spectrogram on Windows computers. RTGRAM is optimised for speech signals and has options for different sampling rates, analysis bandwidths, temporal resolution and colour maps.

RTPITCH - Real-time Pitch Track Display
RTPITCH is a free program for displaying a real-time fundamental frequency track for a speech signal on Windows computers. With RTPITCH you can monitor the waveform and pitch of speech sounds being played into the computer's microphone or line input ports. RTPITCH also has an option to display two pitch tracks and switch between them for intonation practice.

RTSPECT - Real-time Waveform and Spectrum Display
RTSPECT is a free program for displaying a real-time waveform and spectrum display of an audio signal on WIndows computers. With RTSPECT you can monitor the waveform and spectral shape of sounds being played into the computer's microphone or line input ports. RTSPECT can display one or two-channel audio signals.

SFS - Speech Filing System Tools for Speech Research
The Speech Filing System (SFS) is a free software suite running on Windows and Unix systems for the storage and analysis of speech data. It provides a comprehensive environment for speech signal processing, synthesis and recognition.

VOISCRIPT - Scripted Audio Playback System
VoiScript is a program to synchronise display of a script with replay of an audio recording. VoiScript allows you to move around a scripted recording simply by clicking on the script. Since VoiScript also allows you to record your own voice, it is useful in many educational situations. VoiScript comes with instructions about how to author your own audio applications.

VTDEMO - Articulatory synthesis teaching tool
VTDemo is a free program designed to demonstrate how the vocal tract generates different sounds. With VTDemo you can play larynx buzz through a vocal tract that can be manipulated in shape and hear the results.

WASP - Waveforms Annotations Spectrograms and Pitch
WASP is a free program for the recording, display and analysis of speech on personal computers. With WASP you can record and replay speech signals, save them and reload them from disk, edit annotations, and display spectrograms and a fundamental frequency track.

WTUTOR - Web tutorial authoring system
WTUTOR is a system for the authoring and delivery of interactive teaching and learning that we use for our own Web tutorials. WTutor allows you to create tutorials containing multimedia and quiz questions using standard word-processing software in combination with freely available tools. No additional software is required at the student end.

Spectral rotation
A suite of Matlab scripts that perform spectral rotation, of the kind described by Blesser B (1972) Speech perception under conditions of spectral transformation: I. Phonetic characteristics. J Sp & Hear Res, 15: 5-41. For a study that has used this technique, and for examples, follow this link. The software is available via anonymous FTP free of charge but with no guarantees and copyright retained by UCL.

ProSynth Project Deliverables
ProSynth was a research project looking at "all-Prosodic" speech synthesis. A number of data and software deliverables are available.

FIX - Feature Information Xfer
FIX (Feature Information Xfer) is a set of programs designed to facilitate analysis of confusion matrices by both ordinary and sequential information transfer analysis (SINFA - Wang & Bilger, 1973, JASA, 54[5] 1248-1266). The programs may be menu-driven, or run as stand-alone modules. These executables run under MS-DOS on an IBM PC or clone. The programs have also been used under UNIX on a MASSCOMP 5/6000 series computer. Source code may be made available for users with special needs. The software is available via anonymous FTP free of charge but with copyright retained by UCL.

POLYFIT - Polynomial Fitting of auditory filter shapes
POLYFIT is a program for the fitting of roex filter shapes to thresholds measured in notched noise, especially as a function of level. This software implements the procedures described in a series of publications, most recently: Rosen, S., Baker, R. J., & Darling, A. M. (1998) "Auditory filter nonlinearity at 2 kHz in normal hearing listeners," J. Acoust. Soc. Am. 103, 2539-2550. These executables run under MS-DOS on an IBM PC or clone. They are written in ANSI C and source code may be made available for users with special needs. The software is available via anonymous FTP free of charge but with copyright retained by UCL.