Best soundproof interior door
How to soundproof bedroom and apartment door : Best Soundproof Interior Door
Quote from Article entitled How to soundproof bedroom and apartment door:
– STEP 2 – Glue the door surface. In this case, green glue is the best type to use. It is specially formulated to prevent transmission of sound once it has set. You can apply the glue on both surfaces or only on the interior depending on your preference.
The full version of the article can be found here.