Answer by Marc for How do you make your terminal play a sound or offer a notification when it has finished executing its command?

Sound I can't help you with. However, if you append something like

  && notify-send "Task complete."

after your command, you should see a notification pop up in the upper right corner. If the required package is not installed by default, sudo apt-get install libnotify-bin should get it for you. The && will execute a second command if the first completes successfully.