Software

Here you find a list of useful programs being helpful for the generation, analysis and filtering of EVP. Besides a short description you find links to the Websites from where you can download evaluation or freeware copies of these programs.

Sound processing and analysis

CoolEdit

A very versatile audio editor with filter function for removing background noise and general broad band noise from audio signals. Besides many other audio formats, CoolEdit 2000 can also open and save MPEG Layer-3 files (*.mp3). After installing a little free Plug-In CoolEdit allows you to use the new ans license-free audio format Ogg Vorbis which has a better quality and a higher compression compared to MP3. How noisy signals are cleaned using CoolEdit will be described in the article Filtering of Voices using Software CoolEdit 2000 by Rolf-Dietmar Ehrhardt. For a brief introduction into editing sound files using CoolEdit, see the article Editing Sound Files by Tom Butler.

Expander

Expander 1.2 is a small freeware program for slowing down the playback speed of a WAV file without changing its pitch. Although the operation is a bit complicated, it works faster than the Stretch function of CoolEdit and the sound sound quality is much better. The best results for halving the playback speed have been achieved for 44100 Hz signals by the following parameters: 'Expansion Rate' = 2, 'Frame Size' = 2048, Frame Distance = 256, 'Window Function' = 'Hamming' und 'Synthesis Method' = 'FBS'. In the new version 2.0 (Shareware, $20) these parameters are already preset, and it can do now arbitrary expansions and compressions (not only integer-factor expansions).

GoldWave

This audio editor doesn't have the same functionality as CoolEdit, however, it's suitable particularly for evaluating EVP recordings in both forward and backward direction.

UCL Enhance

This is a program for the enhancement of the intelligibility of speech recordings, developed by the Department of Phonetics and Linguistics at the University College London. Download is free.

TrueType-Schriftart für Phonetische Lautschrift

For the documentation of the pronunciation of EVP, the phonetic transcription in International Phonetic Association (IPA) standard as known from dictionaries is suitable. TrueType fonts for Windows and Macintosh can be downloaded for free at the Website of the Summer Institute of Linguistics (SIL) .