From the ALSA wiki
You may decide not to install the
OssEmulation feature since ALSA is the
Way of the Future. If so you must also make sure that you install
versions of other libraries that are linked with ALSA, not with OSS.
You'll know an app is trying to use OSS if it reports it can't open
/dev/dsp (an OSS device). For example, on
Debian the following packages should used:
Retrieved from "http://alsa.opensrc.org/NoOssEmulation"