Can A High Power Ultrasonic Dog Repeller Go The Distance?

Can a high power ultrasonic dog repeller go the distance?  

Distance matters when faced with an aggressive dog, and effective range is influenced by the sound frequency being used.  An ultrasonic’s sound wave will travel a shorter distance than a lower frequency sound wave because an ultrasonic sound wave has many more vibratory cycles over time and distance than the lower frequency sound waves, like those of the Sound Defense.  Ultrasonic sound uses up its energy faster due to the increased number of cycles of vibration it needs to create the sound waves of ultrasonic sound.  The higher the tone, the more compact the waves, the more energy is required to move the vibration through the air.  The more energy needed to move the vibration through the air, the quicker friction acts on the sounds wave, reducing its energy and amplitude.  Ultrasonic dog deterrents emit high-frequency tones.  These ultrasonic sounds lose their energy faster as the sound wave moves through the air.  As a sound wave’s frequency increases, the distance it will travel decreases, and its amplitude will decrease at a quicker rate.  Lower frequency sound, like tones found in dog’s sensitive hearing range, will go further and won’t decrease in amplitude as quickly as an ultrasonic sound wave.  The further the signal can travel and the longer it maintains its power, the better.  When dealing with an aggressive dog, distance matters.  The Sound Defense emits a signal with frequencies in dog’s sensitive hearing range which are far lower than the frequencies emitted by a high power ultrasonic dog repeller.

Outside there are many obstacles that can affect a sound wave such as cars, trees, tree leaves and branches, mailboxes, and so on.  Ultrasonic sounds have shorter, very compact wavelengths.  This means an ultrasonic sound wave is more likely to be stopped by an object in its path than a lower frequency sound wave like those in dog’s sensitive hearing range.  A high power ultrasonic dog repeller has sound waves that are more likely to be absorbed, reflected, or scattered by an object in its path.  Diffraction is the ability of a sound wave to continue around an object as it moves through a medium, like air.  Diffraction won’t happen if the wavelength of the wave is smaller than the obstacle.  The sound wave cannot move around the obstacle in its path if it is smaller than the object.  The sound wave quits moving forward.  Because a high power ultrasonic dog repeller emits sound waves that have shorter wavelengths, there is more opportunity for the sound wave to be blocked than lower frequency sound waves, like those emitted by the Sound Defense K9 Warning DeviceThe lower the frequency, the better the sound wave moves around objects. Sound in dog’s sensitive hearing range is of a far lower frequency than an ultrasonic sound.  The frequencies in dog’s sensitive hearing range are not as susceptible to reflection, scattering or absorption.

Aiming so that the sound reaches the dog is important, and since a high power ultrasonic dog repeller has a smaller beam angle, it is more difficult to aim than lower frequency sound that has a wider beam angle. A high power ultrasonic dog repeller emits a signal that has a smaller beam angle than an audible dog deterrent.  If a person could see sound as it is emitted from a speaker, it may look like a flashlight’s beam.  The width of a flashlight’s beam is called its beam angle.  “Beam angle” for sound is calculated by the sound generator size and the frequency output.  A smaller sound generator is necessary to produce the higher frequency sound.  A smaller sound generator and higher frequency output translate into a more narrow “beam angle” than that of an audible dog deterrent.  A wider “beam angle” like that of an audible dog deterrent like the Sound Defense, would be easier to aim.

The sound’s frequency can be an influencing factor when considering the effective range and aiming ability.  Look for the Sound Defense, which utilizes a lower frequency range in the dog’s sensitive hearing range.

Back to main topic: Dog Repellent