The osstest applet is a simple test application that can be used to test
functionality of the sound hardware installed in the system.

osstest performs a playback test for each installed audio device. If there
are any "machine detectable" problems they will be reported. You will first
hear an audio sample played on the left speaker, then the right speaker and
finally in stereo on both speakers.

NOTE: On NetBSD, use `audiocfg test 0` instead. This package primarily
exists to test OSSv4 compatibility.