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 easy to use noise reduction software to restore poor quality recordings,
especially to increases the performance of automatic speech recognition systems.
The free demo version will process sound files of up to 30 seconds length.
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.
Many sound editors provide a so called Cue List which allows you to mark and label
individual sections within an audio signal very easily. This is suitable for the documentation
of EVP examples. With CueListTool it's possible to copy the Cue List from one WAV file
to another. This is useful if for instance several people are working on a copy of the same
WAV file and want to exchange or merge their results later.
– Digital Audio Reconstruction Technology
A professional program especially for the restoration of noisy and distorted audio recordings.
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.
Professional spectrum analysis software – but unfortunately very expensive...
Speech Tools von JAARS, Inc.
Here you can download various programs for the speech analysis for free.
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.
WAVclean and WAVhum
WAVclean is a rather easy to use filtering program which can be used to "launder"
noisy WAV files. WAVhum by the same manufacturer is a powerful and simple to use hum noise
eraser that removes unwanted cyclic noise from WAV file. A short test showed that the latter
is more effective for EVP. The shareware versions of these programs allow to process only
the first 100 seconds of a recording, which is however sufficient for short EVPs.
MP3 to WAV Decoder / WAV to MP3 Encoder
These programs allow to compress (encode) soundfiles into the space saving
MPEG Layer-3 (MP3) format as well as to decompress (decode) MP3 files back into WAV files.
MP3 files have only one eleventh of the original size and are therefore ideal
for sending EVP examples by e-mail or uploading them on the homepage.
This (MS-DOS) program serves for the generation of acoustic "raw material"
for recordings of EVP by means of random controlled speech synthesis.
A detailed description of this method can be found in the article
The speech synthesis method [P87, 2/97].
With EVPdemo you can archive your EVP examples and add spoken comments to
them in order to create automatically playing demonstrations of them which can
be recorded to an audio cassette or burned to a CD.
Windows program for the generation of acoustic "raw material" by means of
random controlled speech synthesis. Sessions can be logged with questions and answers.
By using a Cue List with WAV files it is possible to use "real" phonemes for
synthesizing "random speech".
EVPatchworker is a Software for synthesizing EVP (Electronic Voice Phenomena).
EVPatchworker enables any owner of a PC with soundcard to synthesize any number of EVP.
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)
To unpack ZIP files, an unpacking program is needed which can be downloaded
as shareware at the following addresses:
If you are looking for a specific software program for download, it might be worth visiting
NONAGS Freeware Shareware World Center