Detecting A Contact Microphone?

[Repeeled]

Hi,

This is a weird one;

We have a new neighbour and, after many months we began to suspect that he might be putting a glass to our party wall and listening to us.

A few weeks back, putting out the bins and I picked up a scrap of paper and it was a receipt for something called 'HY-929'.

Curious, we google the reference and it turns out to be a contact microphone, spy gadget thing that can hear through walls.

Pretty sure that it works because we;ve deliberately said some things and shortly had them repeated back to us.

The question is, can this kind of gizmo be detected when in place / in use and if so, what do I need to detect it?

[zenguitar]

If you have concerns about your neighbours it really isn’t worth the effort. There’s no technological solution to your question. Move house and get better neighbours, it really is that simple.

Andy

[Repeeled]

Thanks for the response, but moving isn't an option.

We were hoping to be able to detect the gizmo and prove the issue to someone who could intercede (we no longer talk to this neighbour) and get it sorted without involving anyone official.

I am surprised though, I thought it might be possible to detect when a contact mike is 'live' and placed against a party wall?

[Hugh Robjohns]

No, of course it's not possible to detect when there's a microphone placed on a wall or even in the vicinity. You been watching too much CSI!

However, I imagine if someone was listening to a contact mic placed against a party wall, they'd find it very unpleasant if you happened to be moving furniture and accidentally kept knocking things against the wall...

I have to say, I find this kind of thing incredibly sad. We get a depressing number of enquiries related to sound-related neighbour disputes. Whatever happened to face-to-face communication, tolerance, understanding, compromise and respect?

[Repeeled]

Thank you for a definitive reply and, you're right, it's all very depressing and I wish I hadn't researched the subject because it gets worse.

Apparently, it's perfectly legal to not only listen but to record as well and some councils advocate it as a way of getting noise nuiscance evidence. Barmy.

[Hugh Robjohns]

Apparently, it's perfectly legal to not only listen but to record as well and some councils advocate it as a way of getting noise nuiscance evidence. Barmy.

You can certainly record sound received within your own property as evidence for noise-nuisance issues. Dogs barking... continual loud arguments or music... domestic violence, etc.

However, what you can't do is make and use recordings of normal private conversations within someone else's home for the specific purposes of harassment or intimidation.

You also can't go through someone else's bins... I suspect there's a lot more to this than you're letting on... and I'm sure no one here really want's to know or get involved!

But it often doesn't require any technology to overhear a neighbour's conversation. I can hear our neighbours conversations sometimes... if the windows are open and one of them is in the kitchen and the other in the lounge so they're talking with raised voices... or when they're on the phone which also seems to result in a naturally slightly raised voice...

I lived in a modern mid-terrace house once where not only could I hear the neighbours raised conversations through the walls quite easily, I could also regularly hear the climactic love-making of the couples living either side of me...

H

[Albatross]

Wonder what the 'estate agent speak' is for a valuable feature like that.

[Repeeled]

Well, it's good to know that cynicism is alive and well and that a simple and polite request for 'expert' advice can bring such unwarranted suspicion and inference.

I shan't trouble you again.

[jaminem]

I cannot imagine how someone has so poor a quality of life that eavesdropping on their neighbours somehow enhances it...

I mean considering the sort of things couples talk about especially if they've been together a while can't be THAT interesting can it? Climactic loveplay or not...

[resistorman]

We put noise through transducers in the walls at a military base.

[resistorman]

A bit on the thin skinned side. I thought it was a very polite and helpful conversation. All in all.

[Sam Spoons]

But TBF, I'd guess that knowing you are being spied on would make you a little sensitive.

[shufflebeat]

Sorry about that, Hugh.

[Hugh Robjohns]

why the apology Shuffs?

[shufflebeat]

I didn't realise we were neighbours.

[Drew Stephenson]

[Hugh Robjohns]

Ah yes... Right.... the man with the very agreeable wife who says yes to everything and gets very excited doing so!

[shufflebeat]

Ah, no - we're the arguing ones.

Sex is such a nasty business and best left to drummers.

[ManFromGlass]

any drum teachers out there? . . . ..

[Hugh Robjohns]

[Wonks]

Sex is such a nasty business and best left to drummers.

But all those loud bleating noises...?

[shufflebeat]

Sex is such a nasty business and best left to drummers.

But all those loud bleating noises...?

Ballad singers.

[sbriverboi]

Sooo.... Im gonna resurrect this for a moment as there is a bit of misinformation and assumption going on here...

From a quick google search, which I suggest some of you try next time before providing advice about an unknown product, revealed a few different models of hy929. There is a contact microphone version, a microphone tube probe, and a few references to an fm transmission function.

Firstly, the probe. If nosey neighbor is using the probe, they most likely would have had to drill a hole, very small just slightly bigger than the probd tube diameter, through your side of the wall for it to work best. This could have been done by hand to minimize noise, or when they knew you were both out of the house. Look around the base boards, or head boards for a teensy hole, possibly with a small bit of white wall dust in front of it. Of course, take pictures if you find one. But if you want to ruin their day, and you know the probe is in place, a little squirt of expanding urethane foam will render the probe useless. It will also work to seal up the passage between your wall and theres. And possibly even get the thing stuck in place which will help the investigation when the cops finally take you seriously.

The contact microphone. this will be a lot harder if not impossible to detect from your side of the wall. The best you can do is get a small metal detector or use the magnetometer sensors in your phone and sweep the walls. If you get a reading that moves around or is only in place when you say things that are later repeated to you you know someone is placing a large metallic magnetized object, ie a microphone, in that spot. There will be a number of false positives nails, power wires, gas lines. But hopefully if there is one there and if you can detect it, youll see a large spike compared to the other readings.

The FM transmitter. This one is easy, get yourself a cheap SDR off of Amazon. The RTL SDR is about $30 with antennas. Using either SDR Sharp or one of the many spectrum analyzer sweeper apps cover different frequency band, about 88 to 108 MHz, note every station you see it will be the large bumps that are wiggling around, tune the software to them listen to them note down which ones are radio stations and which ones are not. Then slowly walk through the house against the shared wall and see any of their associated patterns match the noise you are making. This of course can also help with locating where the microphone is placed as it will get louder and clearer the closer you get to it. It has the added benefit of being able to sweep the entire house for bugs that transmit between 30 MHz and 1.7 gigahertz. Don't be scared by all the spikes you see in the program there is a button of RF energy floating around us all the time every day. You're only interested in the ones that appear to have a pattern associated with your behavior and noise level.

Hopefully this helps you figure out what if any listening devices might be pointed at you. and if not, and you got the sdr, at least you have a cool new hobby downloading weather satellite images and decoding hospital pagers. HIPPA be dammned.

[Hugh Robjohns]

This is all rather depressing, isn't it?

[Kwackman]

This is all rather depressing, isn't it?

Yup.
There's obviously a market for Paranoia!
Do I hear a drill?.....