MadSci Network: Zoology |
Dogs' range of hearing is approximately between 50Hz and 45kHz. Like with humans, no particular frequencies among those are more objectionable than others, but it's reasonable to assume that sensitivity follows a pattern comparable to that of humans, at least in that sensitivity is lowest at the extremes and has a peak somewhere in-between. I am unaware of more detailed studies on canine hearing acquity. So it isn't the pitch that matters, it's how loud the sound is to the animal. You're unfortunate to have chosen dogs as your "pet hate". Given the fact that their range of hearing differs only by just over an octave from humans' it means that their maximum sensitivity will be well withing the human range of hearing and that only the area between 20kHz and 40kHz is eligible for use in this particular application. There too, some care must be exercised. Even though tones beyond 20kHz are inaudible by themselves, people who are continuously subjected to an ultrasonic sound field (as in the area of ultrasonic cleaners) regularly suffer from headaches or nausea. Also, young children often have a range of hearing extending up to 30kHz and even higher for asthmatic kids. So, apart from dogs you may well find yourself scaring off about any hearing form of life, including your kids. As for how to constrain dogs to {world\your house} without having to lock yourself up you could consider "half doors" as they used to be common here in Europe. The door would be split into two halves with the top half usually open and the bottom half closed. Cheers, Bruno
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