Sound absobtion prac

Discussion in 'Supporting Physics' started by Tonytech, Oct 11, 2017.

  1. One of our teachers does a sound absobtion practical every year.
    A buzzer sits in a box surrounded by foam/paper/bubble wrap/ etc.
    A decibell meter is placed close by and readings taken for several thicknesses of insulation.
    The prac rarely works due to backgrond noise.. Other students apparatus.
    The teacher has considered putting the meter in the box, but like schrodingers cat it cant be observed. :)
    Does anybody have a way to do this... I can buy datalogging sensors, but I only have 3 interfaces and 4 computers....
    We are looking into using mobile phones with monitoring apps, but I'm not convinced.
  2. As a demonstration, we used a speaker connected to a Sig. Gen.
    Placed materials between the speaker and dB meter.
    material used , chipboard, cardboard, polystyrene, carpet
  3. we do the same as AlF. I have an egg tray, some foam, and a muslin bag filled with plastic loft insulation. We don't do anything quantitative with it, just as a demo where the students listen to it, but we do have sound sensors for our dataloggers, we could make up a class set.
  4. Former_user

    Former_user Guest

    Hi Tony,

    Don't know if below any use?

    Dont know decibel meter size, but what about putting meter inside differing sized tupperware boxes and buzzer on the outside?

    So place meter inside a tupperware box, which then get placed inside another larger tupperware box and so on?

    The alternating plastic surfaces and trapped air gaps inside the Tupperware boxes should deaden sound sufficiently and Tupperware allow you (hopefully!) to be able to read the decibel meter screen still. Avoiding the schrodinger's cat conundrum :D

    I've never done this though, so not entirely sure whether works, but I can't see why it wouldn't.... :)
    Tonytech likes this.
  5. how about speaker in a box giving noise of a known frequency then insulate and use a phone app such as the one in this video

    then only background noise of the same frequency would matter

Share This Page