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osstest - Open Sound System audio self test applet.
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The osstest applet is a simple test application that can be used to test
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functionality of the sound hardware installed in the system.
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osstest performs a playback test for each installed audio device. If there
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are any "machine detectable" problems they will be reported. You will first
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hear an audio sample played on the left speaker, then the right speaker and
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finally in stereo on both speakers.
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It's user's responsibility to listen if the test sound is audible. If no
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sound output can be heard the possible reason is one of the following:
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1. An error was reported by osstest. In this case there will usually not be
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any sound output. The error needs to be fixed before running osstest
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2. There is no headphones or speakers connected. Or the connection is not
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3. The mixer volume level is set to a too low value. By default it should
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be OK. The mixer level can be adjusted using the mixer, ossmix and ossxmix
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utilities distributed with OSS.
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4. Some notebooks have nonstandard volume control and/or speaker selection
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hardware that is not supported by OSS. It's very likely that OSS doesn't
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support such vendor specific additions.
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If no errors were reported and the test sound was audible it means that
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OSS and your sound hardware is functioning correctly. If you still encounter
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problems with some sound applications the reason is almost certainly in
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the application. Check it's configuration or try to use another equivivalent
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If you are having problems with JDS, KDE and/or Gnome system sounds, you need
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to make sure that OSS gets started before the GUI environment. Refer to your
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operating system's startup procedures.
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The osstest utility measures a sample rate drift value after playing
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back the test sound. Ideally it should be 0% but in practice there
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will be an error of few percents. 0% means that the 48000 Hz test file
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was played exactly at 48000 Hz sampling rate.
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The sample rate measurement is based on the system timer which has limited
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precision. It's likely that less than 1% differenc between the nominal and
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the measured sampling rates are actually caused by an error in the measurement.
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For this reason the drift reported by osstest should not be used as any kind of
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quality measurement. However if the drift is very large it means that there is
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something wrong in the system. The oscillator chip used with the sound chip is
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broken or the system clock is running at a wrong speed.
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USING OSSTEST MANUALLY
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The osstest utility is located in the /usr/bin directory. It can be run
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manually to test functionality of OSS and your sound hardware. When invoked
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without any command line parameters osstest performs the default test on all
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devices. However it will skip some of the devices base on the following rules.
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o It is possible to test just one of the available audio devices by giving
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its number on command line (for example osstest 1). Use the device index
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numbers reported by "ossinfo -a".
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o Use the -l command line option to loop the test infinitely.
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o Virtual mixer devices will not be tested. Use the -V command line option to
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force test of virtual devices.
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o The actual (physical) audio devices will be tested directly (bypassing
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virtual mixer). If you want to test playback through vmix then use the
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o Multiple device files related with the same physical device will not
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be tested. Only the first one gets tested while the remaining ones will be
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skipped. At this moment there is no way to force osstest to test this kind of
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o Only stereo devices will be tested. Future versions of osstest will be
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able to test mono and multi channel devices too. Also osstest requires that
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the device supports the 16 bit signed format and 48kHz sampling rate.
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o Send a SIGQUIT (Ctrl-\e on most terminals) to make osstest skip a device.