I can hear you…

Meet my one and only, ominous looking…

Sound Reflector
Sound reflector!

With this amazing piece of equipment, I can listen to your footsteps from across an entire field, I can eavesdrop on conversations, so you better not say anything bad about me!

Well, at least that’s what it should do. In reality, there’s still a lot of problems with it. Hey, I only spent about half an hour on it!

So, first of all, how did I come about this ‘idea’? Well, in my freshmen seminar, the heat engine group built a huge solar collector dish, probably about 1 metre in diameter, and while checking it out, I realised how effective it was at reflecting sound waves. Stand with your head at the focal point, and if someone behind you starts speaking, it sounds as though they are speaking right into your head, even if they are a decent distance from you.

Then I came across this dish, which they had used for testing and preliminary ideas, and they weren’t using it anymore, so I just asked whether I could borrow it for a while, and thus came into existance this sound reflector!

So what are the problems with it? First, I can’t place the microphone right at the focal point, because that’s inside the black arm which extends out. Second, whatever material this dish is made from, it certainly isn’t that great at reflecting sound – it only seems to reflect high frequency sounds (treble as opposed to bass). Which is why I hear lots of footsteps but not much more. Lastly, the ‘focal point’ I’ve currently set up the mic was ‘calculated’ using light, and not sound (since if I put my head in there it kinda blocks off all the sound), so it’s probably not correct anyway.

Still, it was fun. And nope, I didn’t build it to listen in on other people’s conversations, but rather just for the experience, and I had always been interested in directional microphones. Now all I have to do is to get that $150 1 metre diameter dish, put an access point at the focal point, and set up a point-to-point wireless connection, say, across 20 kilometres. How’s that sound? Sounds good to me!

Dish2

4 Comments

  1. Cat-chan says:

    Hi Hoong Ern, Merry Christmas~

    Your sound reflector reminds me of the sound reflector things they have outside the Otago Museum that reflect sound. 'course, they're a lot bigger and there are 2 of them. I'd say both are about 2 meters in diameter and are about 5 meters apart.

    All the same, I think your sound reflector is quite good, everything considered. =^^=

    Happy New Year~!

  2. keShia says:

    aaaaaaaaaaaaaaaaahhh..
    that's scary. ahhahahaha 🙂
    why do you want that for?
    a secret documentary! oh so cool 🙂
    bless you 🙂

    • Stormy says:

      To second Dave’s comment … but sounding a more moderate note … the scientific community has always numbered among its members committed political conservatives like John von Neumann, whose 1956 essay Can We Survive Technology? is a classic of foresighted political analysis having strongly conservative foFidatnons.uor some unknown reason, genuinely thoughtful conservative voices like von Neumann’s have mostly fallen silent in recent decades … while at the same time “.”

  3. Joshuachin says:

    wahahahaha
    sounds fun....can kepoh ppl whenever u want!

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