I believe that this is because kernels past the 2.6 era switched from using OSS as the main sounds driver to ALSA.
As you have noted, ALSA does not provide the same functionality and the /dev/dsp directory is vanished.
It is possible that the OSS modules are installed somewhere, but are not loading at boot.
If that is the case, then
code:
sudo modprobe snd-pcm-oss
If OSS is not installed at all, then you will need to potentially recompile the kernel with OSS enabled.