[SOLVED] Unable to open mixer /dev/mixer

Problem:
If you get an error in terminal saying “Unable to open mixer /dev/mixer” or “Could not gain access to /dev/sound/dsp for writing.”. You can resolve this problem by installing “libsnack2-alsa” package. If you are trying to install “libsnack2-alsa” package “wavesurfer” is going to uninstall, if wavesurfer is already installed.

You will get this message:

The following packages will be REMOVED:
  libsnack2 wavesurfer
The following NEW packages will be installed:
  libsnack2-alsa

Error:

Unable to open mixer /dev/mixer
OR
Could not gain access to /dev/sound/dsp for writing.

Solution:

$ sudo apt-get install libsnack2-alsa

I hope this will help you, If you got another solution please do write in comment. I love to hear that.