When Do People "Hear" Ultrasonic Frequencies?

Children and young people are more sensitive to ultrasonic waves and may hear a portion of the sound output from Yard Gard, silent to most other humans' ears.

If you or others can hear the unit, we don't recommend sitting within range due to discomfort  however, rest assured that the unit's output is below the threshold to cause any damage to hearing or cause other physical harmThe sound is not pleasant but the volume is well under any level of intensity (loudness, decibels) that would cause injury, whether or not it is "heard." Ultrasound makes animals leave by making treated spaces uncomfortable, not dangerous. The Yard Gard output specification is 90 decibels at 1 meter. This is the equivalent of truck traffic noise at one meter.

Sound intensity drops swiftly with distance, so at greater distances such as four to five meters – more commonly experienced by users  the sound intensity reduces considerably. The relevant physics equation shows that at a distance of four meters the intensity drops to 78 decibels, i.e sound level similar to dial tone (80 dB), a bit louder than conversation (65 dB) & softer than city traffic inside a car (85 dB).

Occasionally any ultrasound device, just like many useful tools, can become a problem when it is not used according to instructions. While the Yard Gard sound output is well within safe levels, to the small number of individuals who DO hear its lower frequencies, the sound is not pleasant.

ultrasound safety         

In fact, using slightly different frequencies, in the UK and Europe other manufacturers have actually designed ultrasonic devices with the express purpose of dissuading young people from loitering on public or private property. So there is little doubt that those who can hear in this frequency range may not care for the experience.

Be a Good Neighbor

For this reason, it is important to behave courteously in the case of any reports of discomfort. Good neighbors do not deploy a Yard Gard pointed directly into someone else’s yard at short range, or toward anyone who dislikes and cannot avoid it, any more than they would blare music from loudspeakers or use a leafblower 24/7. This is simply common sense & good manners.

In the case of hearing a Yard Gard, usually, a polite request to the owner is all that is needed. Typically they are unaware of any problem, and gladly cooperate when asked. Proper use of the Yard Gard unit includes directing its output within the confines of one’s own property, and not pointed at people or confined pets. This is clearly stated in the instructions.

Here at Bird-X, we are always willing to work with anyone who needs an alternative method of pest control in order to solve a pest issue and keep on good terms with neighbors who may be especially sensitive. One excellent choice is the highly effective organic Nature’s Defense granules, which repel 22 different pest species from mice all the way up to deer and every pest critter in-between. When consideration and cooperation join together, a win-win solution can always be found – and Bird-X is here to help.