#language en
~-[[DebianWiki/EditorGuide#translation|Translation(s)]]: English - [[fr/SoundConfiguration|Français]] - [[it/SoundConfiguration|Italiano]] -~
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[[Hardware]] > [[Sound]]
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To listen to sound (Ogg, [[MP3]], .au files, CDs etc.) on your [[SoundCard|sound card]], you need to:

 * Run a [[Kernel|kernel]] with the correct sound drivers for your sound card (See [[SoundCard]] for information about your sound cards). The PC sound cards are Sound Blaster compatible.

 * Load the required modules for your sound card if using a modular kernel.

 * Install sound packages.

 * To configure alsa, you might have to run {{{alsactl init}}} as root.

You can install too e.g. [[http://freshmeat.net/browse/113/?topic_id=113|Sound/Audio apps]] or [[http://www.underbit.com/products/mad/#using|Applications using MAD]], 'xfreecd' (music CD playing software), 'mp3blaster' (full-screen console mp3-player), or 'saytime' (if you have no CD drive and no [[MP3|MP3s]]). Try to run them as root (it should work). With Debian, ordinary users lack permission to read the CD drive and write to the audio device (usually {{{/dev/dsp}}}), and they probably can't use these programs (yet; see next paragraph).

 * Use '{{{adduser USER_NAME audio}}}' to allow a specific user to write to the {{{/dev/dsp}}}, {{{/dev/mixer}}} and {{{/dev/audio}}} devices and thus output sound from the soundcard; note: the user needs to log off and on again for such changes to take effect! This is the recommended way to allow a user to play audio. If, instead, you changed the permissions of the {{{/dev/audio}}} etc devices to make them accessible to anyone, that would open a security hole because you would be allowing any trojan to read the microphone device.

 * better is to add your user to the audio group

 * To allow some users to play music CDs on the CDROM drive: '{{{ls -al /dev/cdrom}}}' to check which special file {{{/dev/cdrom}}} is a symbolic link to. If it is {{{hdc}}}, then do: '{{{chgrp cdrom /dev/hdc}}}' or if it is something else (e.g. {{{/dev/scd0}}}) do the corresponding thing. Then do '{{{adduser USER_ID cdrom}}}' to allow the user to play music CDs. Changing the group of {{{/dev/hdc}}} (or {{{hdb}}} or whatever) is necessary, because otherwise you would need to add the user to group disk, which is bad for security.

 * If you run xfreecd, remember to change the default CDDB server on the 'xfreecd' software from 'cddb.cddb.com' to 'gnudb.gnudb.org'. This is best done by directly editing the '{{{.xfreecdrc}}}' file in the home directories of the users who use the program.

== Testing ==
 *  {{{speaker-test}}} - command-line speaker test tone generator for ALSA



== Alsa / OSS ==
There are two main projects, that aim to provide sound drivers in Linux.

 ALSA :: [[ALSA]] is the main current set of sound drivers in Linux. It provide some modules ({{{snd-mixer-oss}}}, {{{snd-mixer-pcm}}}, {{{snd-mixer-seq}}}) to emulate OSS with legacy application.

 OSS :: [[OSS]] was the original sound drivers.

To switch between ALSA and OSS, you should run:
 {{{dpkg-reconfigure linux-sound-base}}}
(see {{{/usr/share/doc/linux-sound-base/README.Debian}}})

=== ALSA ===
Some useful commands:
 * {{{alsactl store}}}/{{{alsactl restore}}} - save/restore the volume settings (this is normally performed on shutdown/boot)

The documentation is in {{{/usr/share/doc/alsa-base}}} (as usually!)

== Unix Group ==

If you notice that a user starts up Gnome and receives a message about Audio not working the likely cause is that the user is not in group audio (only the initialy created user is in the {{{audio}}} group by default). You need to:
{{{
  # adduser john audio
}}}

Next time user john logs on they will be able to use the audio device.

See also:
 [[DebianMan:8/adduser|adduser(8)]].


== See Also ==
 * [[SoundCard]] - supported sound cards
 * [[ALSA]]
 * [[SoundFAQ]]
 * [[http://www.linuxjournal.com/article/6809|Configuring your laptop for Gnome and sound]].

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CategorySound