We moved your post to this original discussion. You'll see that @EricL gave the following fantastic advice:
To stop draught from entering the gaps between the door frame and the door, I suggest using the Raven 5m Door And Window Seal - RP14 White. You can also use the Sperling 78cm Double Sided Draught Stopper to stop the wind from entering through the bottom of your door.
Here is a handy guide to give you more ideas: How to winter-proof your home
Please let me know if you have any more questions about this or if we can help you further. We're always happy to help.
Hi @wookienz , having gone through sound reduction in our home earlier this year, there are several issues to be considered. Firstly, although aluminium doors are strong (good security) and stable, they are not good at keeping out either temperature or sound. Aluminium , being light & stiff is pretty good at following sound waves. It is sometimes used in microphones to pick up sound. So that's probably why you are noticing the noise. To cut down sound requires density of materials used. Are you able to replace the door with a solid wood one? Otherwise, it may require drastic measures such as sticking something more solid to the inside surface to dampen its transferring of sound vibrations. But you can start by trying to seal all around the door with dense rubber seal. That's not the hole-y stuff used as draft stopper. It will have a rubber skin on the surface, not little holes. You may have to get it from a rubber specialist (eg Clark Rubber). Also seal across the door bottom (I attached that strip to the door itself, but other sides go on the frame.) I have a dble glazed, timber frame door but I was surprised how much noise dropped by fitting the (correct) rubber seal around it. I hope that helps you get in the right direction.
It's great that you've received fantastic advice from @TedBear. I totally agree with his recommendation. Your door is currently transmitting ambient sounds from outside to inside your home. Increasing its density is a good way to stop the transfer of sound. I recommend using Standard Carpets 1000 x 1000mm Charcoal Polypropylene Carpet Tile it has a PVC backing that is almost like rubber. However, if you wish to get a thicker panel you can use Ultimate Flooring 1 x 1m Rubber Gym Tile - Black.
I suggest using the Sika 1L Clear 105 ContactFix Premium Contact Adhesive to glue the rubber panel onto your door. If you use the thicker rubber you may have to mount it with the ContactFix Adhesive and screws. Please keep us updated, we look forward to seeing your door insulated.
If you need more advice or information, please let us know.