#6764 NORM Never A: White noise on recordings

[Zarro Boogs per Child]

#6764: White noise on recordings
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 Reporter:  ssb22   |       Owner:  jg            
     Type:  defect  |      Status:  new           
 Priority:  normal  |   Milestone:  Never Assigned
Component:  distro  |     Version:                
 Keywords:          |    Verified:  0             
 Blocking:          |   Blockedby:                
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 I tried recording some birdsong with the internal mic and the Record
 activity, on a B4 test machine running update.1 691.  When played back,
 there was significant "hiss" (white noise) on the recording.  There was no
 obvious acoustic source for this noise, so it's probably coming from the
 sound electronics.  I wondered if anything can be done about that.

 Looking at the output of "amixer contents", there is a controller called
 'Mic Boost (+20dB)' which had its value set at 'false'.  So I tried:

 {{{
 amixer sset "Mic Boost (+20dB)" true
 }}}

 and I *think* it made it slightly better, but it was hard to tell.  (White
 noise was still present.)

 Mic boost should be used only with dynamic microphones, not electret
 microphones (it can cause distortion with these).  Do we know what type
 the OLPC's internal microphone is?

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Ticket URL: <http://dev.laptop.org/ticket/6764>
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