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7147Researcher asks: Anybody try to screen off the Hum with Faraday cage?

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  • andrewyassin
    Oct 2, 2006
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      Hi all,
      I hear the hum and so does my wife. This is in south Lapland, North

      As a research physicist I have access to great instruments to attempt
      to solve this puzzle.

      I have read a lot about the hum, and actually done some very precise
      acoustic measurements. However, the results were that there was NO
      audible signal present at all, even though I could hear it loud and
      clear while measuring.

      I could measure down to 6Hz with very high sensitivity (20dB L-Eq;
      that is linear response over the entire spectrum - no filters) using a
      Bruel&Kjaer 2260 investigator.

      For infra-sound to be perceptible, very high signal levels are usually
      required; that is above ca 90dB L-Eq at 16Hz and increasing with
      decreasing sound frequency.

      This is a truly amasing piece of instrumentation - in Nort sweden it
      could pick up a concorde starting in Paris. However, no luck with the hum.

      Next week I'll do some vibrational studies as well using either a
      Geophone or an accelerometer. Such data might correlate to infra-sound
      loggings made by the IRF at www.irf.se (institute of space physics,
      Umea university). Possibly my hum might come from hydroelectric power
      plants. If so I'll surely be able to measure it.

      However, if the hum is of electromagnetic origin - it should be
      possible to screen off the perceived sound by creating a Faraday cage.

      Did anybody yet rule out that possibility?

      Please post if you tried to screen it off using a proper cage!

      Best regards,
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