On Sun, 19 Feb 2012 17:53:37 +0000 Fons Adriaensen <fons@xxxxxxxxxxxxxx> wrote: > On Sun, Feb 19, 2012 at 04:11:55PM +0100, Renato wrote: > > > I'd like to understand how the sensors work, but his site doesn't > > seem to go much in depth on this... it says the sensors register > > the sounds of the undercutaneous muscles. But are those even in the > > audio frequency realm? And how would you capture them, with a piezo > > contact mic? > > There was a paper on this at LAC 2011, see the proceedings. > <http://lac.linuxaudio.org/2011/?page=download> > again, thanks Fons. For the lazy, the actual sensor device is described at page 160 (170 of the pdf) of the proceedings pdf [1]. It's basically an electret condenser microphone, kept in place by a silicon case that should also filter out external noise. So he's (knowingly) leaving out part of the spectrum, since as he describes earlier in the article muscle sounds are in the 4-45hz range and those mics go down to only about 20. I must say I'm quite surprised to learn muscles make loud enough sounds to be used this way... and this project of his looks freaking cool IMO. renato [1] http://lac.linuxaudio.org/2011/download/lac2011_proceedings.pdf _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
