Sound recorders are a must have tool. We use ours firstly to record witness accounts or details of activity that the owner of a property has encountered. When this is played back it is possible to concentrate on specific events and to better document the salient points for future use.

Another use is to record the investigation as it happens, very useful to listen to later, who heard or saw what and in what order, a very valuable aid to accurately documenting events.

The analogue recorder of the type shown above is really only useful for use for these two types of use, the quality is not great and you really need to use a clean tape each time, which can make them expensive for investigation use.

Digital recorders are now available at prices that make them an affordable and economical alternative. One of our digital recorders is shown below.

Digital recorders can also be used try to record EVP (Electronic Voice Phenomenon) during investigations, a purpose for which they are ideally suited. The recorder can be left in a suspected haunted location and may capture a noise or an EVP, later the sound can be directly downloaded onto a PC for analysis.

One Important point on the use of digital recorders. If you use compression, part of the compression algorithm is to restrict the recorded audio frequency range to that, that can fall within human hearing, EG 20Hz to 20Khz for the minimal compression, 120Hz to 8Khz for the greatest compression. EVP's are normally found from 1.8Khz right up to 20Khz, hence Digital is good as long as its not compressed.

For our younger readers the human ear can hear 20Hz to 20Khz at best, 80Hz to 9Khz for the older readers, which sadly seems to include me.

We normally take a PC or laptop to investigations and regularly dump electronic data to it for later analysis, but in doing this we free up our important equipment for reuse.
If You are going to record vigils make sure you keep a record of file names or tape numbers when and where a recording was taken and when it finished. You can do this conveniently on the recording at the beginning by saying the time, the area and who is present in the area.

As long as your watch was set accurately and everyone else has synchronised his or her watches events in different locations can be accurately linked. As part of this we set one watch to the Greenwich time signal and then use this to synchronise the rest.

Bear in mind that most tape based recorders are not noise free and in any case the quality of some of the built in microphones as questionable. It is always better to use an external microphone, these can be directional, boom types or boundary types.

Directional Microphones do exactly what they say on the tin, although most conventional mikes are to some point directional. Boom mikes can be set up on a tripod to insulate them from surface sounds or of course you can put them close to the ceiling to hear footsteps above.

Boundary Microphones are omni directional and can hear over 360 degrees with virtually the same degree of sensitivity. These "can" be more expensive, but guarantee that you do not miss a peep either from EVP's or at a vigil, where they will pick up every tiny sound. As a group we have a mix of all of these types, the most used are the normal and boundary microphones. A boundary microphone is attached to the digital recorder shown above.

One important point if you are using recorders with micro or other sorts of tape. Tapes can slip slightly side to side on the tape head and can be significantly out of line machine to machine. For these reasons either use a new tape or one that has been completely erased with one of the degaussing tape erasers. Otherwise you may think you have recorded a noise, when in fact you are hearing snatches of something recorded previously.