I was looking for software which is able to cut audio files into smaller pieces, for example I set seconds and miliseconds for beginning and end of cutting, and then I can save cut content as new file.
Audacity is capable of doing this.
Audacity is a free, easy-to-use and multilingual audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems. You can use Audacity to:
avconv can do this.
-ss is start time
-t is duration
Install libav-tools to make it happen.