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
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
CoolEdit allows you to use the new ans license-free audio format
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 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).
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.
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)