Users can plug in their headphones to the bluetooth wireless remote which allows for quit listening late at night or in noisy rooms. There are also volume controls on the side of the remote that control the volume level of the headphones.
If you don't want 4K content, Roku 3 might get you more bang for the buck
Since 4K content is still scarce it might be better to get Roku 3 instead. It's practically identical to Roku 4 except for voice search and 4K support that Roku 3 lacks.