After digging threw some command i found this error.

root@Microknoppix:/home/knoppix# cat /dev/sndstat
Sound Driver:3.8.1a-980706 (ALSA v1.0.21 emulation code)
Kernel: Linux Microknoppix 2.6.32.6 #8 SMP PREEMPT Thu Jan 28 10:51:16 CET 2010 i686
Config options: 0

Installed drivers:
Type 10: ALSA emulation

Card config:
--- no soundcards ---

Audio devices: NOT ENABLED IN CONFIG

Synth devices: NOT ENABLED IN CONFIG

Midi devices: NOT ENABLED IN CONFIG

Timers:
7: system timer

Mixers: NOT ENABLED IN CONFIG