Tenta fazer o seguinte, vai no terminal e execute o comando:
sudo gedit /etc/modprobe.d/alsa-base
No arquivo que abrir, insira o seguinte ao final dele:
# ALSA portion
alias char-major-116 snd
alias snd-card-0 snd-intel8x0
options snd-intel8x0 index=0
options snd-intel8x0 buggy_semaphore=1
# module options should go here
# OSS/Free portion
alias char-major-14 soundcore
alias sound-slot-0 snd-card-0
# card #1
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss
# OSS/Free portion - card #1
alias sound-slot-0 snd-card-0
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss
# OSS/Free portion - card #2 (cmipci)
alias sound-slot-1 snd-card-1
alias sound-service-1-0 snd-mixer-oss
alias sound-service-1-3 snd-pcm-oss
alias sound-service-1-12 snd-pcm-oss
Salve e reinicie o computador.