Proximity sensor that doesn't bother dog/cat's hearing?

Hey everyone!
I’m looking for a proximity sensor that doesn’t use sound within the 45Hz to 64kHz range, but would work with an arduino without too much issue. Any suggestions would be helpful.
The project I have in mind will be mounted to the vest of a pet, needs to detect range, and work inside and well as outside (so lots of ambient light from sun or modern LED lamps).

The sensor I found is the US-015 and sends ultrasound at 40kHz. But it looks like dogs can hear frequencies from 67Hz to 45kHz while cats hear at 45Hz to 64kHz… so something outside of those ranges, this way it doesn’t bother the pet. Maybe a light emitting sensor maybe?
Ultimately, I’m looking for a combination of sensors to cover 360 degrees, about 6 feet away max distance.

I need it to do the following, in order of priority:

  1. Detect objects within 2m (6ft. or so)
  2. Update around 100 times a second or faster
  3. Not irritate animals with sound
  4. Reasonably cheap so they can be easily replaced when broken or lost
  5. (optional) Detect/report distance

Any ideas/suggestions would be greatly appreciated! I’d like to not have to set up reflectors everywhere in order for this thing to work.

Are you sure it’s sound? Sound is a mechanical wave, as opposed to, say, Wi-Fi or zigbee or Bluetooth, which are electromagnetic. (This is why sound doesn’t travel in space but Wi-Fi can.)

A lot of bloggers on the Internet get this wrong, not understanding the difference between an electromagnetic wave and a mechanical one. But dogs can’t hear light and they can’t hear WiFi transmissions or Zigbee transmissions.

If the sensor is sonar-based, then, yes, the dog can probably hear it. But if it’s a radio frequency, the dog probably can’t.

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Thanks for the response! I just read over my post and it’s a bit garbled and confusing - I’ve edited it.

The sensor I’m referring to is this little guy here (Adafruit US-015 sensor). It’s definitely sonic, and looks like it emits a 40 kHz frequency.

Basically, this is the perfect sensor except I need to replace it with something that isn’t ultrasonic. Microwave, light, radio, I’m not sure yet

Thanks for the details. I’m still confused about the details of the use case, though. Why would you need it to update “100 times per second or faster”?

The term ““proximity sensor“ is used in two different ways. In robotics, it is used so that a moving object, like a drone or a robot, knows where it itself is in space and can guide its trajectory accordingly. those may indeed need readings multiple times per second.

In home automation/security it’s normally used to detect when an object has moved into range of the sensor. These often are set to detect once a minute or so to avoid false alerts.

Even if you wanted something to detect a dog running towards a pet door, for example, something that detects every couple of seconds should be sufficient. Definitely not more than 100 times per second.

So which kind of proximity sensor were you looking for, and why do you need something that fast? (Among other things, anything which is sending a radio signal that frequently is going to eat through batteries like crazy.)

Is this something that the dog is going to be wearing? Or walking towards? Or running towards? Is it going to be powered by mains power or battery? Is the purpose to activate another device like a pet door or a light? Or to track where the dog is if the dog leaves a detection zone?