How to stop/reduce ultrasonic sound wave device?

[bluetuliphead]

I have a random but pressing question.
I am currently being blasted a nearby ultrasonic noise machine which I can only get within 2 metres of and there is no one to appeal to regarding the issue.
How can I disable/reduce the noise given the constraints?
This is the device.
https://katycraft.com/product/powerful-ultrasonic-garden-squirrel-repeller-deterrent/

I have tried every other avenue regarding this issue so I am turning TO SCIENCE! Thanks in advance for any ideas.

 

[jedishrfu]

It sounds like your neighbor has placed this on their lawn and its pointed at your property. Is that right?

First step, I'd get a decibel app for your phone like the Decibel X:dB Sound Level Meter app on the Apple AppStore. Its free with in-app purchases but sufficient to measure the strength and frequency of the ultrasonic pulses.

https://www.soundly.com/blog/best-decibel-meter-apps

This way you'll know its not psychosomatic as people taking certain medications may have auditory hallucinations.

Next, I'd check the specs of the device to see if it broadcasts in the range detected by the sound level meter. This way you'll know its from that device.

Next, I'd show the neighbor whats going on and that you might file a noise complaint about it with the police in small claims court. They may be able to place it so its not aimed at your property. Alternatively, you could hire a lawyer to handle the matter.

There is no way scientifically of eliminating the noise completely short of shutting it off. You could wear noise cancelling headphones although they might not cancel ultrasound at the frequency thats emitted. You could use soundproofing in your home but that costs money, would only be effective indoors and may not work as well as you'd like.

It's always better to work with your neighbor to get it resolved as legal actions and clandestine actions backfire and make things worse especially with a vindictive neighbor.

 

[Klystron]

I have tried every other avenue regarding this issue so I am turning TO SCIENCE!

Hi blue tulip. @jedishrfu covers your options quite thoroughly in post #2, perhaps suggesting alternate avenues for mitigating your problem. Sampling and creating a record of the offending sounds, as suggested, is an inexpensive project.

Technically, sounds waves can be sampled and a counter sound wave generated that cancels the annoying sound with varying levels of success. In practice this requires relatively expensive electronic equipment including directional microphones, MIDI controllers, integrated amplifier and speakers, and computers running the sampling and broadcasting software. Electronic musicians and audio hobbyists likely have access to this equipment.

More simply, one can apply various sound reduction strategies to your environment. The high frequency squeals used to bother small mammals are difficult to inhibit. Some humans and pets, sensitive to these sounds, are bothered as much as wildlife. Many cities have sound ordinances that apply to your situation.

Consider compromise with the offending neighbors such as changing direction of their broadcast and placing timers on their devices that restrict when they operate. Ideally, they switch to non-audio squirrel controls once your problem is presented.

 

[Baluncore]

How can I disable/reduce the noise given the constraints?

It constitutes a legal nuisance if it radiates across a boundary.

If legal methods fail, escalate. Fight sound with sound.
Install a hidden ultrasonic microphone on your property. Down-convert the received signal to low-frequency audio. Replay that through a hidden speaker aimed back at the neighbour controlling the ultrasonic source. Gradually increase the gain and power until the neighbour turns off their ultrasonic generator.

 

[JT Smith]

What does it sound like? If it's ultrasonic how do you know when it's running? And why are they using it?

A friend bought a similar priced device to stop the neighbor's dog from barking. It was just a battery operated toy that didn't really do anything to affect the dog for more than maybe a second or two.

If you can't negotiate with the neighbor and you can't get the authorities to help you then you're sort of screwed. Learn to live with it or move. Or turn on Taylor Swift music full blast and leave for the day.

 

[jedishrfu]

I think the Barney song would be more appropriate:



There are several other songs that can spice up your relationship with your neighbor that I'm sure you're familiar with.

 

[Vanadium 50]

I think the Barney song would be more appropriate:

Doggone asteroid missed one.

I am with @JT Smith here. How do you know its on? If you can hear it, its not ultrasonic.

 

[bluetuliphead]

OK so when it goes off, I can hear it and see the lights going at the same time so I know I'm not crazy. This is the app recording. It spikes to the right every time it goes off. Is this a frequency range most people can hear? It's between 13000 and 17000 hz. I'm 32 so I thought I'd be too old to hear that?
Legal/ police route not pursuable like I said. I need practical work arounds however laborious.

 

[Baluncore]

That looks like about 15 kHz, which children can hear, but not usually adults.
15 kHz to 50 kHz will affect you. You will feel irritable and confused, but you will not know why because you do not know where the irritation comes from. The effect is like having an untreatable headache.

The advantage of down-converting and replaying is that the operators will not know why they can hear their own ultrasonic deterrent. Maybe the manufacturer will exchange it for another, or they will get their money back.

 

[bluetuliphead]

That looks like about 15 kHz, which children can hear, but not usually adults.
15 kHz to 50 kHz will affect you. You will feel irritable and confused, but you will not know why because you do not know where the irritation comes from. The effect is like having an untreatable headache.

The advantage of down-converting and replaying is that the operators will not know why they can hear their own ultrasonic deterrent. Maybe the manufacturer will exchange it for another, or they will get their money back.

I would love the privilege of a confusing headache. I'm not trying to flex my youthful ears but I can hear it and I know I'm not wrong because I hear the epic screech, I check and indeed, it's sound on light is on.

Are there ways to insulate against setting it off? I think it goes off of a heat sensor?
I appreciate this is hardly the cerebral physics I'm sure you're normally here for. But this is practical bumpkin physics. Help the young earred sad person plz

 

[Baluncore]

Young ears can hear up to 20 kHz, so it would not surprise me if you can hear it.

Are there ways to insulate against setting it off? I think it goes off of a heat sensor?

Some movement detectors could be blinded with a continuous IR LED, others might be jammed by an IR noise signal. You might blind it physically by painting its sensor black.

You would need to identify the type of sensor used.

 

[bluetuliphead]

Young ears can hear up to 20 kHz, so it would not surprise me if you can hear it.

...

You would need to identify the type of sensor used.

I thought at 32 I wasn't young enough anymore but sadly, I can hear it!

So I believe its a PIR. Unsure how I'd blind that without physical options

 

[Flyboy]

I am assuming that talking to the neighbor about possibly replacing the unit with a higher frequency output is not an option?

If so, then yeah, jamming the sensor is the best option.

Orrrrr… it’s solar powered, right? Throw something over the solar panel, like a leaf or something, and secure it in a way that’s not obvious. It’ll run out of power in a few days, tops.

 

[DaveE]

Can you take a picture of it and show us?
Are the sensors (whatever they are) pointed at your house, or in the other direction?

 

[Vanadium 50]

If so, then yeah, jamming the sensor is the best option.

And only a little crime-y.

IMHO, he should:

1. Talk to the neighbor
2. Talk to the police
3. Talk to a lawyer

It sounds like he is between the 1st two steps. He should not jam or otherwise interfere with the device.

 

[jack action]

How can I disable/reduce the noise given the constraints?

https://dsiac.org/technical-inquiries/notable/defeating-passive-infrared-motion-sensors/

The PIR sensor basic principle of operation depends on the difference in IR energy between an intruder and the background. The sensor detects the presence of an object when its field-of-view is blocked by an object that has a different temperature than the background. As a passive device, the sensor does not transmit a signal. Instead, the sensor responds to the energy emitted by a human intruder, which is approximately equivalent to the heat radiated by a 50-watt light-bulb. The PIR sensor responds to either the heat energy emitted by a human body or changes in background radiation caused by a person blocking the background in the sensor’s field-of-view. Using a variety of lenses, the detection pattern is subdivided into the solid angular segments. The electrical signal varies when a heat source moves out of one solid angular segment into the next, providing detection of a heat source in motion. Logic circuitry is usually applied to the received signal to differentiate among various situations. If the signal pattern matches that of a person in motion rather than generalized heating and cooling, an alarm is generated. The PIR sensor is more sensitive to motion across the field-of-view than to motion toward or away from the sensor. By properly designing the optics, the PIR sensor’s field-of-view can be tailored to provide various coverage patterns.

An intruder who appears to be the same temperature as the background is invisible to the sensor and could create a vulnerability.

So if you flood the sensors with a heat source (similar to a 50-watt filament light bulb), when an animal goes in front of it, the sensor won't see the difference between the background and the animal.

Pro: Probably not illegal. Con: It will be difficult to fine-tune it.

 

[Baluncore]

Arguing legality, assumes you know the country, and the national jurisdiction to which this matter is subject. That I do not know.

If the neighbour is permitted to cause a nuisance, then we must assume you have a reciprocal right. That is why down-conversion and re-radiation as audio is possible. It puts them in control, and you have a counter-claim if they take the issue to the law.

Avoid trespass and damage to property. Follow the legal path. It is understandable that, once someone is disempowered by all the normal processes for resolution, they will turn to violence. That is the way of the world.

 

[berkeman]

If so, then yeah, jamming the sensor is the best option.

So if you flood the sensors with a heat source (similar to a 50-watt filament light bulb), when an animal goes in front of it, the sensor won't see the difference between the background and the animal.

Pro: Probably not illegal. Con: It will be difficult to fine-tune it.

Taking the US as an example, since the FCC does not regulate IR interference (AFAIK), it might be possible to use an IR laserpointer with a precision aiming mechanism to overload the PIR sensor in the device.

Quiz Question -- what common household item would you use to fine-tune the aiming of that laserpointer in a stealthy way, and what time of the day or night would you do that?

 

[Klystron]

That is why down-conversion and re-radiation as audio is possible.

If the OP must take action, down converting the ultrasonic to audio sound range, amplifying the sound and rebroadcasting over outdoor discreetly positioned speakers, seems the lessor evil.

The audio broadcast equipment is essentially identical to your outside sound system for playing music or announcing guests at your front door. Position one or more outdoor speakers mounted to play toward the noise source when countermeasures required.

Continue sampling the noises on a phone or small computer with indoor/outdoor microphones sensitive to the offending noises. Develop your counter-broadcast signal and pipe it through your house sound system. Could be as simple as playing a song or animal vocalizations when the nuisance noise bothers you, avoiding the need to down-convert*.

Obey all laws and sound advisories, counter-broadcasting only during approved music hours, at approved volume levels without 'obscenity'.

FYI an outdoor shopping strip in Santa Cruz CA played amplified classical and baroque music over loudspeakers in an attempt to discourage skateboarders fragging the concrete. The skaters retaliated by wearing earbuds and noise-cancelling headphones. Neighbors complained about all the noise.

* Subsonic noise below human hearing thresholds can be detected (felt) by body cavities including stomach and nasal cavities. Effects vary but have been described as OP posts. Woofer speakers produce low frequencies while tweeters emit high frequencies. Typical weatherproof outdoor speakers play midrange (fine for this discussion).

 

[berkeman]

BTW, just to amplify (not sorry for the pun) the option of working something out with your neighbor instead of using the other options...

When I worked at HP a number of years ago here in Silicon Valley, there were a few months where the R&D floor where I worked was temporarily partially used for a manufactuiring line. Management was moving things around in the building, and needed to locate a manufacturing line right next to our Engineering cubicles for a while during the transition. Should be no problem, right?

Except that the Mfg folks liked to play local radio stations during their shifts pretty loudly, to help ease the repetitiveness of their assembly work. Unfortunately, that ended up being pretty distracting for the R&D types like me, who had to focus in on our design work and not make any intellectual mistakes.

So (I'm not admitting to being one of the R&D ringleaders...) we decided to use our intellectual prowess and RF instruments to jam their FM radio receivers so that we could regain our peacefully quiet R&D Lab environment...

You can imagine how that went and what happened next. We spent so much time re-tuning our RF signal generator to jam their FM radios as they kept switching stations that it was not an efficient solution. I think in the end we just finally walked across the aisle and asked them politely to use earbuds. Live and learn.

 

[sophiecentaur]

Technically, sounds waves can be sampled and a counter sound wave generated that cancels the annoying sound with varying levels of success.

Only over a small localised region (particularly for ultrasound wavelengths.

, once someone is disempowered by all the normal processes for resolution, they will turn to violence

You're gonna need a bigger squirrel to take offence at the noise.

But you have my sympathy; bad neighbours are bad news.

 

[Baluncore]

Technically, sounds waves can be sampled and a counter sound wave generated that cancels the annoying sound with varying levels of success.

The wavelengths here are all less than one inch.
The sound will need to be cancelled separately for each ear, and for any part of your head that is sensitive to ultrasound.

 

[Klystron]

The wavelengths here are all less than one inch.
The sound will need to be cancelled separately for each ear, and for any part of your head that is sensitive to ultrasound.

The original response was to try noise cancelling headphones. Even if the nuisance noise exceeds normal operating specs, the sound proofing should provide some mitigation for sensitive users.

Suggest: ambient sound OFF, noise cancelling ON.

If too expensive a solution, 3M makes decent ear protection headphones roughly 1/10 the cost. My simple 3M headphones cost ~$35. (room for extra earplugs inside)
My fancy Sony noise cancelling headphones ~$350.

 

[Baluncore]

Active noise cancellation technology works well for frequencies under 500 Hz. It fails completely above 1 kHz. There will be absolutely no cancellation benefit at 15 kHz.

 

[DaveE]

BTW, just to amplify (not sorry for the pun) the option of working something out with your neighbor instead of using the other options...

When I worked at HP a number of years ago here in Silicon Valley, there were a few months where the R&D floor where I worked was temporarily partially used for a manufactuiring line. Management was moving things around in the building, and needed to locate a manufacturing line right next to our Engineering cubicles for a while during the transition. Should be no problem, right?

Except that the Mfg folks liked to play local radio stations during their shifts pretty loudly, to help ease the repetitiveness of their assembly work. Unfortunately, that ended up being pretty distracting for the R&D types like me, who had to focus in on our design work and not make any intellectual mistakes.

So (I'm not admitting to being one of the R&D ringleaders...) we decided to use our intellectual prowess and RF instruments to jam their FM radio receivers so that we could regain our peacefully quiet R&D Lab environment...

You can imagine how that went and what happened next. We spent so much time re-tuning our RF signal generator to jam their FM radios as they kept switching stations that it was not an efficient solution. I think in the end we just finally walked across the aisle and asked them politely to use earbuds. Live and learn.

Yep, I had a nearly identical story back in the day. A guy in the lab next to us liked to listen to Rush Limbaugh's show at high volume, which we didn't want to hear. My Tech complained and boom.. two cheap function generators and 5 minutes later, I arranged for no more Rush. My rules were 1) only that show, 2) only if you can hear it and are annoyed, and 3) low power transmissions only. He never figured it out, his radio worked great for everything except that one show.

One of the more practical applications of the radio classes I took in school.

 

[Klystron]

I may misunderstand the specs on the Sony WH-1000XM5 noise cancelling headphones. Both the Sony and Dell website state noise cancelling range:

FREQUENCY RESPONSE	4 Hz–40,000 Hz (JEITA)
FREQUENCY RESPONSE (ACTIVE OPERATION)	4 Hz–40,000 Hz

While one can doubt this wide a [cancellation] response, particularly at the higher frequencies, the specs clearly exceed human audio bandwidth even for children and adults sensitive to anti-squirrel chirps. Be interesting to test these specs in an audio lab with calibrated measurements.

Dell URL:
https://www.dell.com/en-us/shop/son...74bd96fc34c798f40&gclsrc=ds#techspecs_section

Sony URL:
https://electronics.sony.com/audio/headphones/headband/p/wh1000xm5-b

I have tested a combination of 3M ear protection headphones over 3M earplugs at the Clark County shooting range both subjectively and with a hand held sound level meter scaled in dB. Noise dampening worked well even standing close to rifle fire.

 

[Baluncore]

4 Hz–40,000 Hz is simply the bandwidth of the signal being reproduced for your ears.

It does specify the attenuation of external sound to the internal chamber and your ear. Nor does it specify how that transfer function changes when active noise cancellation is turned on.

 

[sophiecentaur]

I reckon that a quick spray of the transducer with clear laquer would sort out the problem and the neighbours would never know.

 

[JT Smith]

I just tried out my Bose noise canceling headphones with an online tone generator. I compared them with canceling turned on versus off and found that they attenuated the tone up to something around 6000Hz. At 7000Hz there was no noticeable attenuation.

My headphones are quite effective at blocking all sorts of sounds, particularly when coupled with playing lively music. But I'd be surprised if they would be effective at blocking a really high pitched tone, especially without Megadeath on full blast. About ten years ago I bought a pair of Sony noise canceling headphones to hopefully deal with a barking neighborhood dog. They were useless and I returned them. I came up with a different strategy.

 

[Baluncore]

About ten years ago I bought a pair of Sony noise canceling headphones to hopefully deal with a barking neighborhood dog. They were useless and I returned them. I came up with a different strategy.

Use an ultrasonic generator that is triggered by the dog's bark. The dog will voluntarily provide positive feedback. The dog will get locked up somewhere, out of bark range.