HOBI Animal Alert Test Reports

International field testing for HOBI alert whistles

Figure 2.5: Voice spectrums measured for free flow. The figures on the left shows the voice spectrum when
ΔP = 0.0042bar and on the right when ΔP>0.0317bar.The hearing range for moose, deer and other wild animals range from a few hertz to over 20,000 hertz. As seen in diagram 2.5 Hobi emits sound at least up to 40,000 Hz (measured between 50 – 40,000 Hz) According to Professor R. Silvennoinen, Ph. D., with Joensuu University in Finland, the Hobi Ultrasonic Animal Alert works. He explains the test in the following manner: When a vehicle is travelling at a speed of 100 km/h. one Hobi produces a sound of 102 decibels In the same situation a pair of Hobi produce 105 – 106 dB. Volume at 50m is 68,7dB and at 100m still at 40 dB

“Figure 2.8 shows the pressure differences caused by various speeds proportioned to the measuments taken for free flow…..The figure also shows that the frequency curve magnitudes are relatively high between the speeds of 70 km/h and 100km/h when comparing them to the maximum magnitude of the curves. This proves that the whistle does make a sound when driving at these speeds.”“Figure 2.8 shows that the spikes begin to be high enough to be properly heard at 80km/h -100km/h"Study of Wildlife Alert Whistle
Harri PaatialaMaster’s Thesis Laboratory Study
November 2004
Department of Physics
University of Joensuu

“In my opinion, the tests show that the wild ruminants occuring in Finland in large numbers are able to hear the sound caused by the whistles tens of meters away and react to the sound in the same way as to any other stimuli deviating from their normal sound enviroment. Positive reactions were also achieved with several other animal species.”

January 31 2005
Kaarlo Nygrén,
Ilomantsi Game Research Station,
Ilomantsi, Finland

We 'determined that the drivers in question did not encounter wildlife and game. This includes roads that are normally crossed by wildlife or game. We assume that this can be attributed to the presence of the warning device.'

January 21 1980
Veterinaerrat Dr. Josef Koenig
President, League Against Animal Torture and Abuse of Animal Testing
Vienna, Austria

'We tested the device on horses to see if the sound would startle them and the test proved quite conclusively that it does not have any negative effect on horses.'

December 27 1984
I.I. Hughes
Executive Vice-President, Ontario Humane Society
Newmarket, Ontario, Canada

'Inaudible frequencies in the range of 16 - 19 Khz were detected from A, "A" being the Holbie Model (Hobi Model). The speed at which inaudible frequencies were generated was approximately 35 miles-per-hour.'

June 8 1988
James E. Morin
Calibration Lab Manager, Trans-Bay Electronics, Inc.
Richmond, California, USA