Animals and particularly dogs have often been seen to behave oddly or "freeze" in the presence of paranormal activity. Dogs have sensory perception that is different to a human. Their hearing can sense up to 50KHz, which is way beyond the human upper threshold of around 18KHz (and lower with old age). Acoustic energy above 20KHz is known as "ultrasonic" and there are various devices that use this frequency range, for instance car alarms and parking sensors. Bats also use ultrasonic for echolocation and use frequencies up to 100KHz. Some paranormal teams have tried to detect energies in the ultrasonic region, but there are no readily available "wide-band" instruments capable of covering the 20 to 50 KHz band.
* Typical response up to 50KHz
* Wideband response, which does not require tuning
* Backlit display for use in total darkness
* No resets
* Envelope detector and audio connector for headphones etc
DETECTING AND MEASURING ULTRASOUND
Using a Spectral Electronics Canum I (Ultrasonic Listening Device)
Theories in paranormal and psychic research suggest that spirit entities may communicate through higher vibrations than the living. Typically a human can sense sound up to approximately 18KHz, while other animals such as dogs with a higher sensory perception are able to hear sounds in a range up to 50KHz. Dogs in particular are believed to behave oddly or "freeze" in the presence of supposed paranormal activity, hence the name of the equipment as Canum is Latin for Dog. Acoustic energy above 20KHz is known as "ultrasonic", and the Canum is calibrated to detect sounds within this range up to 50KHz.
The canum can be used in a similar fashion to the EMF Meter during investigations. Again it is important to perform a 'baseline sweep' of your location prior to commencing vigils to ensure that there are no naturally occurring sources of ultrasound. Any readings captured during vigils can then be compared to the baseline tests, thus offering an objective means of comparison. Specific experiments that can be employed typically involve attempts to verbally communicate with a spirit entity either through a medium or attempting to converse through a sťance. In the event that a spirit energy is able to verbally respond, any sudden or spontaneous measurements of ultrasound through the Canum could indicate some evidence of this.