If you have a sliding barn door that looks like the one in the picture below then you will probably need a bit more than a small weather strip to stop the noise.
Soundproofing sliding barn doors.
Attaching acoustic panels to your barn doors is another effective option.
You can attach this acoustical foam block on the entire length of the door.
First off the wood you are using should be heavy and thick that s the principle behind noise blocking.
Else you are planning for an ugly scene.
Sliding barn doors are the easiest sliding doors to soundproof in my opinion which means that you have plenty of options to do this.
You can buy what s called a soundproof foam corner block amazon link.
Get a barn door style sliding door a thick door made of solid wood is better than glass or hollow wooden doors for blocking noise.
Soundproofing barn door using this method is a bit of a risk.
Weatherstrip the door as you can see weatherstripping the door is very important since it s something you have to do for every door you want to soundproof in general no matter what kind of door it is.
During installation the plywood or mdf panel you intend to use should be cut to the precise measurements of the door.
To soundproof a sliding barn door make sure there are no gaps or cracks that noise can travel through.
Make sure the doors are made from solid wood meaning a solid and not a hollow core.
A door sweep and weatherstripping tape can be used to cover gaps.
There are two types of acoustic panels.
However the down side to this option is the price.