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Bouncing back or blocking high frequency sound outdoors?

  1. Jun 10, 2010 #1
    Hello everyone, I'm new here. :smile:

    Because I feed wild birds in my garden, my neighbour has mounted an electronic bird scaring device on the outside corner of her bedroom windowsill angled so that it is pointing directly over my fence into my garden. :mad:

    This device is meant to be an 'almost silent' device made by http://www.martleyelectronics.co.uk/silent-bird-scarer/64-mp1b-silent-bird-scarer.html" [Broken], and it works by playing different high frequency sounds in a loop. I can hear various whistling and whooshing noises, soft clicks and loud clicks (like someone is repeatedly clicking their fingers)

    The local authorities here can't act on it as a noise nuisance, but I'm advised by the manufacturer that the sound would be diverted from the birds by placing something between me and the sound. I would still be able to hear it though.

    Is there any reasonably simple way of deflecting the sound back to it's source, or disrupting it, or do I have to plant trees along my fence and wait years for them to grow?

    Thank you in advance if anyone can suggest anything that might help. :smile:

    I'm not technically a 'twitcher' as that is someone who goes everywhere to see a particular bird. I'm just a 'birder' who like watching birds and taking photos of them. :smile:
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 10, 2010 #2
    Surely that is not the reason....does your neighbor object to you eating, too??

    Have you spoken with her to find out what her problem/concern is? Are the birds some sort of nuisance in her yard??

    How about mounting a big searchlight on your side and pointing it her way??
  4. Jun 10, 2010 #3
    My neighbour stopped speaking to me over a year ago when I hung a peanut feeder on a large branch of her tree that overhung my garden. I had asked her if it was OK to hang a feeder on there years before, but she took exception to the latest one as the birds could take whole peanuts and they were dropping bits of them as they were eating them in her tree. She cut off every overhanging branch of the tree. :cry:

    There are currently more starlings than usual because of all of the fledglings, so I suspect it's either the poop in the garden border or the noise. But it is my fence.

    I put a very nice polite note through the door, but received no reply.

    I'm now trying my best to stop the high frequency beam.

    I thought a large basketball backboard about 11 feet high might probably do the job.

  5. Jun 11, 2010 #4
    You might try asking a building code inspector what electrical connection is required for such an outdoor device...my guess is she has a wire leading inside to an interior wall outlet and that's not likely code. But that will just cost her money for an exterior waterproof outlet.

    Another approach is to hire a lawyer, ask what recourse you have, maybe write your neighbor a "cease and desist" letter....she likely won't know if it's enforceable...nor do I.

    I did not read any details except the hi freq "speaker" description, so that sounds like it's audio. A basketball backboad will have virtually no effect uness MAYBE it's really close to the speaker.

    You might want to research "noise cancellation" devices.....start here:
    http://en.wikipedia.org/wiki/Noise_cancellation...you'll [Broken] have to find a commercial device if one exists in the frequency range of the MArtley. You are trying to accomplish what the ads for the BOISE noise cancelling earphones claim to do.

    I'd also call or e-mail Martley about the technical specifications of their product...power and frequency, and ask what conditions adversly effect their products effectiveness....

    But I don't think audio cancelling over a wide area like a yard is simple nor cheap.
    Last edited by a moderator: May 4, 2017
  6. Jun 11, 2010 #5
    Thanks for your reply Naty1

    I never considered the building code inspector angle so I will look into that. I've been trying to avoid the lawyer angle for the time being, but it may come to that.

    I've spoken with the manufacturer. He's the one who advised me that it's a loop of different sounds. It sounds as though it works like a disc playing several tracks and then repeating them.

    I've currently given her a month to reposition it so that it doesn't point over my fence into my garden. She has already had a problem though because a mother has already complained that her son can hear it in his bedroom through her thick conifer hedge. That was before she started turning it off overnight.

    Yes, I suppose I am trying to achieve what noise cancelling headphones do. I'm not necessarily trying to make it so that I can't hear the noise because I don't think that's possible, but I don't want it to scare off the birds. According to the manufacturers it's relatively straightforward to divert it with foliage, but this device is on the corner of a first storey windowsill so the trees would have to be quite big.

    I wondered if the basketball backboard might be up to the task while the trees grow. I also wondered if metal might divert the sound back better than foliage.

    I will try what you have suggested though.

    Thanks again.
    Last edited by a moderator: May 4, 2017
  7. Jun 11, 2010 #6
    I'm not a lawyer but I am guessing she has a right to try and repel birds from her property but not from yours. Therefore I think you'd would okay in trying to block the signal from her yard as long as you don't violate any other laws. A basketball backboard might well be the easiest and cheapest way to block the signal. If she then decides to move the device to bypass the backboard, then you may have a case to cease and desist.
  8. Jun 11, 2010 #7
    My guess is foliage would absorb sound better than a hard surface like a basketball backboard....High frequency sound should be easier to suppress than low frequency, like bass sound, but if I were erecting a pole I'd check on an appropriate material to use rather than just guessing.
  9. Jun 11, 2010 #8
    You might find something of interest here:


    It gave me the idea (but is not mentioned) that maybe you could contact a bird society/Audubon society and see if they have any objections or information about such bird sound repellent devices.....Maybe they would be willing to send a letter of warning about potential harm to birds to your neighbor....
  10. Jun 12, 2010 #9
    Hi skeptic, That sounds reasonable, however she has a very high conifer hedge that the birds have allways nested in plus a tree between our 2 properties where she has fed them in the past and occasionally still does (when she remembers to refill her peanut feeder). So the birds are habituated to those 2 places. If she wants to repel birds from her property, the easiest way would be to reduce the height of the hedge. This is something she has always refused to do in the past.
  11. Jun 12, 2010 #10
    Hi naty1, That is something I couldn't decide about. The metal backboard would be more dense, whereas trees would let some sound filter through, especially in the winter months if they were deciduous.

    I know for sure that I can't make the fence higher than 6'6" as that is the maximum height here, even with trellis on top. However, I can have trees (not a high conifer hedge) or any structure that wouldn't be considered permanent like a basketball backboard, or any sporting equipment.
  12. Jun 14, 2010 #11
    Maybe you could convince some squirrels to chew the wires?
  13. Jun 22, 2010 #12
    Another possibility: Suppose the device were mounted on the fence (or nearby pole) and pointed toward your neighbor's house....

    some possibilities:
    (best) your neighbor agrees and it keeps the birds from heryard, but allows them in yours....

    (most fun) if the volume is adjustable, mount your own duplicate device to drive your neighbor crazy until she takes hers down...
  14. Jun 22, 2010 #13
    Hi Naty1
    Amazingly I went out at about 8.30am in the morning and took photos of the bird scarer then made an appointment to see a lawyer about an injunction that afternoon. Within 20 minutes of my making the appointment she had taken it down, and I had to postpone my appointment. Since then it hasn't gone back up, so I'm holding my breath. I have purchased a 20ft tree though, and plan to plant it in October

    Thank you for your help. X
  15. Jun 22, 2010 #14


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    A Mythbusters (beating sensing devices) way for bouncing back or just blocking high pitch noise is a fine woven sheet of material, as the texture behaves like the walls in a cinema for that type of noise. Yes your bedsheet will do.

    It's not a solution in your case but it is a start.
  16. Jun 22, 2010 #15
    Hi Lok

    That's really interesting, and it sounds like something I could easily try if it goes back up. The fixing bracket that it sits in is still on the windowsill, so it might reappear.

    Thank you for your reply. X
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