pofis@pofis-laptop:~$ lsof /dev/dsp* /dev/snd/*
COMMAND    PID  USER   FD   TYPE DEVICE SIZE NODE NAME
kmix      5228 pofis   10u   CHR  116,0      8872 /dev/snd/controlC0
kmix      5228 pofis   11u   CHR 116,32      8937 /dev/snd/controlC1
firefox-b 7544 pofis   41u   CHR   14,3      8861 /dev/dsp