$ sudo apt-get update
$ sudo apt-get install decibel-audio-player 

decibel-audio-player is installed in your system.

Make ensure the decibel-audio-player package were installed using the commands given below,

$ sudo dpkg-query -l | grep decibel-audio-player *

You will get with decibel-audio-player package name, version, architecture and description in a table

decibel-audio-player package basic information: