it doeesnt always work.
try:
$ sudo apt-get install alsa-tools
then create a new document and paste the following:
#!/bin/bash
sudo hda-verb /dev/snd/hwC0D0 0x20 0x500 0x1b
sudo hda-verb /dev/snd/hwC0D0 0x20 0x477 0x4a4b
sudo hda-verb /dev/snd/hwC0D0 0x20 0x500 0xf
sudo hda-verb /dev/snd/hwC0D0 0x20 0x477 0x74
make sure the created file is of type 'sh'.
then run the file using './fileName' on the command line.