Stop PulseAudio processes

# killall pulseaudio

Remove all pulseaudio packages

# apt-get purge pulseaudio pulseaudio-utils gstreamer0.10-pulseaudio libpulse-browse0 paman pavumeter pavucontrol

Backup sound configuration

# mv /etc/asound.conf /etc/asound.conf.bak

Remove user configuration

$ rm ~/.pulse-cookie $ rm -r ~/.pulse

Install ALSA packages

# apt-get install alsa-base alsa-tools alsa-tools-gui alsa-utils alsa-oss alsamixergui libalsaplayer0