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posted by takyon on Friday August 12 2016, @02:34PM   Printer-friendly [Skip to comment(s)]
from the I've-heard-it-all dept.

EPFL scientists have invented a new type of "acoustic prism" that can split a sound into its constituent frequencies. Their acoustic prism has applications in sound detection. [...] Hervé Lissek and his team at EPFL have invented an "acoustic prism" that splits sound into its constituent frequencies using physical properties alone. Its applications in sound detection are published in the Journal of the Acoustical Society of America .

The acoustic prism is entirely man-made, unlike optial[sic] prisms, which occur naturally in the form of water droplets. Decomposing sound into its constituent frequencies relies on the physical interaction between a sound wave and the structure of the prism. The acoustic prism modifies the propagation of each individual frequency of the sound wave, without any need of computations or electronic components.


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  • (Score: 0) by Anonymous Coward on Friday August 12 2016, @02:38PM

    by Anonymous Coward on Friday August 12 2016, @02:38PM (#387029)

    That [...] is hilarious, like it was placed there to highlight the echo in the first paragraph.

  • (Score: 2) by opinionated_science on Friday August 12 2016, @02:39PM

    by opinionated_science (4031) on Friday August 12 2016, @02:39PM (#387031)

    might be useful for airports....

    • (Score: 0) by Anonymous Coward on Friday August 12 2016, @03:49PM

      by Anonymous Coward on Friday August 12 2016, @03:49PM (#387062)

      .....to analyze the voiceprints of suspects for terrist tendencies, of course!

      ALLAHLAHLAHLAHLAHLAHLAHLAHLAH!!!

  • (Score: 1, Informative) by Anonymous Coward on Friday August 12 2016, @03:27PM

    by Anonymous Coward on Friday August 12 2016, @03:27PM (#387055)

    Went to the link, http://scitation.aip.org/content/asa/journal/jasa/139/6/10.1121/1.4949544 [aip.org] and found paper "Exploiting the leaky-wave properties of transmission-line metamaterials for single-microphone direction finding" Neat stuff, correct author (Hervé Lissek) but no prisms.

    Searched for acoustic prism on Scitation and found a bunch of older papers (2015 back to the '80s). Then tried Lissek prism and no hits at all.

    Did I miss something? Or did the editor not check the bot's link?

    • (Score: 2) by takyon on Friday August 12 2016, @03:35PM

      by takyon (881) <{takyon} {at} {soylentnews.org}> on Friday August 12 2016, @03:35PM (#387059) Journal

      I think the discrepancy is that Lissek calls it a "transmission-line acoustic metamaterial" or "acoustic leaky-wave structure", while the EPFL has chosen to dumb it down by calling it an "acoustic prism".

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      • (Score: 4, Informative) by AudioGuy on Friday August 12 2016, @04:12PM

        by AudioGuy (24) on Friday August 12 2016, @04:12PM (#387068) Journal

        Acoustic prism would not have been my choice as a descriptive term for this.

        Ordinary directional microphones exibit a falloff of high frequencies as you go off axis. What this does is greatly exaggerate that effect using an acoustic tramsmission line with resonant chambers and membranes. Enough that it is useful as a direction finder. If you feed it 600-1400 Hz you can get a nice plot of direction vs freq.

        I'd simply call it a new technique for audio direction finding, which is commonly done with multiple microphones. This works with one.

        It doesn't seem to work at all like a prism to me.

        It does seem like it might have applications in sonar, and in providing a good income to the company that makes this rather complex microphone. :-)

      • (Score: 1, Informative) by Anonymous Coward on Friday August 12 2016, @04:19PM

        by Anonymous Coward on Friday August 12 2016, @04:19PM (#387073)

        (same AC) No, it's worse than that, the abstract makes it clear that this is about directionality of sound, last line:

        This introduces the concept of sound source localization without resorting to beam-steering techniques based on multiple sensors.

        Searching the full paper, the word "prism" only appears in the Intro when discussing prior art. Not at all in the body of the paper.

        Also, in the paper there is nothing about "Decomposing sound into its constituent frequencies". "Decomposing" does not appear in the paper. "Frequencies" appears a few times, context is testing the directionality at different frequencies.

        Pretty clear that http://actu.epfl.ch/news/acoustic-prism-invented-at-epfl/ [actu.epfl.ch] links the wrong paper.

  • (Score: 1, Insightful) by Anonymous Coward on Friday August 12 2016, @06:41PM

    by Anonymous Coward on Friday August 12 2016, @06:41PM (#387119)

    LOL You might want to open such acronyms OMG

    • (Score: 0) by Anonymous Coward on Friday August 12 2016, @07:12PM

      by Anonymous Coward on Friday August 12 2016, @07:12PM (#387131)

      Swiss call it MIT of Europe. Maybe other Europeans disagree, but I understand it's regarded highly in STEM fields.

    • (Score: 3, Informative) by c0lo on Friday August 12 2016, @11:12PM

      by c0lo (156) Subscriber Badge on Friday August 12 2016, @11:12PM (#387236) Journal

      1. click the first link of the story
      2. note the epfl.ch domain
      3, look on the left up corner and read "Ecole Polytechnique Federale de Lausanne"
      4. spare the time posting your question, use it better
      5. ...
      6. profit

      (grin)

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0
  • (Score: 3, Interesting) by Azuma Hazuki on Friday August 12 2016, @06:50PM

    by Azuma Hazuki (5086) on Friday August 12 2016, @06:50PM (#387124) Journal

    Audio to MIDI conversion. It would be trivial for a good programmer to write something that takes the output of one of these and makes some very clear MIDI transcripts of what's coming through it. If you can construct the prism such that it splits along the Western tonal scale (A = 440Hz etc) in theory you can get an almost perfect MIDI transcription of whatever's being played.

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    • (Score: 2) by c0lo on Friday August 12 2016, @11:18PM

      by c0lo (156) Subscriber Badge on Friday August 12 2016, @11:18PM (#387239) Journal

      Not quite. Try for yourself: you could do the same using FFT.

      If you think of the timbre/tone of various music instruments, you'll understand why.

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0
  • (Score: 0) by Anonymous Coward on Friday August 12 2016, @08:15PM

    by Anonymous Coward on Friday August 12 2016, @08:15PM (#387160)

    Can this be used in reverse to convert it back into a sound mix after modifying some parts? Kind of like using Audacity to filter or otherwise modify audio files. Also, what about using it to power a speaker for each constituent frequency? That would probably be the absolute best audio reproduction possible. Perhaps use plasma speakers... no moving parts or cones.