Hi again rwmalin456-ga,
As typically defined, ultrasonic is the frequency higher than the
nominal audio frequency range as measured in hertz (Hz.) The human
audio frequency range is 64-23,000 Hz.
Ultrasonic animal control devices use frequency ranges above our
hearing range but within the hearing range of the animals we are
trying to control. The assumption is that the high frequency sound is
annoying to the animal in question and will serve to repel or contain
it. Whether or not these devices work is still subject to debate, but
for the purposes of your question, we?ll operate on the premise that
In that case, we need a frequency that is above our range of hearing
but is within the cow?s range. A cow?s hearing is between 23-35,000
Hz. So anything in the 24,000 to 35,000 Hz range should do the job.
Here is a chart of hearing ranges for various animals
How Well Do Dogs and Other Animals Hear?
According to this website, cows are agitated or aroused by high
frequency sounds and clamed by low frequency sounds.
Here is a good overview of how ultrasonic devices work and a
discussion of their efficacy.
Electronic Pest Control Devices
If you are considering marketing such a device in the US, you may want
to read this FTC warning:
FTC Warns Manufacturers and Retailers of Ultrasonic Pest-control Devices
That should give you what you need. If any of the links don?t work,
let me know. Good luck with your project.
Thanks for your question.
hearing frequency cow
ultrasonic rodent control frequency