The simplest, and currently suggested approach, is to use the
asoundconf command. 
  # alsaconf
if it still doesn't work for normal users, try add this user to audio group.
   # adduser lax audio

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Liu Lantao
College of Information Science and Technology, Beijing Normal University
EMAIL: liulantao ( at ) gmail ( dot ) com ;
WEBSITE: http://www.liulantao.com/ .
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