[LAU] iPad and Linux audio

[Robin Gareus]

On 02/19/2012 07:33 PM, Renato wrote:
> On Sun, 19 Feb 2012 17:53:37 +0000
> Fons Adriaensen <fons at linuxaudio.org> 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.

Video of the presentation and direct link to the PDF:
  http://lac.linuxaudio.org/2011/video.php?id=17
  http://lac.linuxaudio.org/2011/papers/30.pdf

> renato
> 
> [1] http://lac.linuxaudio.org/2011/download/lac2011_proceedings.pdf
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