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I need to measure a noise. i need the volume and frequency.

  1. Nov 30, 2005 #1
    my a/c-heater unit thing in my dorm is making this very irritating high pitched noise. maintenance can't hear it. so i need to prove that it's there (this is important because i live in a 12 month dorm and will be here this winter).
    are there any programs or devices that will measure frequency and volume?
    how could i go about doing this?

    hey.. delete one of these threads.
  2. jcsd
  3. Nov 30, 2005 #2


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    Science Advisor

    You need a microphone and a spectrum analyzer. What kind of school are you in? Does it have an engineering department? If you do happen to have a prof that is familiar with this area, you could record the sounds (i.e this is the time domain signal). You would then take it to someone with an analyzer and have it processed into the frwquency domain and voila. Your noise turns into a nice pretty spike for all to see.

    I did a quick yahoo search and the first page that came up was this:

    I'll bet you can use your sound card and find some shareware out there to do what I was talking about. Get Googling!
  4. Nov 30, 2005 #3
    we have a physics department... i think they send the engineers off to some other school though.

    i asked a physics professor and he showed me the audioscope program... it didn't seem to have volume ratings on it.
  5. Dec 1, 2005 #4


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    You don't really need volume in this kind of analysis. What you need is to simply show that the noise is there in relation to other noises. That's what the FFT will show.
  6. Dec 1, 2005 #5
    is there any special way i should record it? will a pair of really nice headphones work as a microphone in this case?

    is there any media that i should avoid using (like tapes or cd's etc...)?

    will the quality of the "microphone" change the readings?
  7. Dec 1, 2005 #6


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    Staff: Mentor

    A good quality microphone and your oscilloscope will show it. If you don't have an oscilloscope yet, then as your advisor prof if you can borrow one for the weekend or something.
  8. Dec 2, 2005 #7


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    The better the quality the better the results, but I would imagine any microphone you can get your hands on will work. I'm not sure how headphones would work for this application. That's not what you need.

    For large tests, we routinely record transient data on reel to reel tapes for playback at a later date. I would think a personal tape player would be ok if it doesn't induce too much static noise. Give it a try.
  9. Dec 2, 2005 #8
    Hu, I've tested many different softwares and among them are the audio softwares that can do exactly what you want: recording. All you really need is a software that can record and display the wave of the noise being recorded on the monitor...Almost all audio software I know does this. You can get one free. If you only want to use it temporarily, just do a search on google and you can download what's called a "trial version". But if you want to use it permanently you'll have to buy it.
  10. Dec 3, 2005 #9


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    OR you could have downloaded Total Uninstall, and downloaded whatever trial program through there. Once you time is up, you can "totally uninstall" it, and re-download the trial edition, to use another 30 days. :smile:
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