How to Keep the Sound Inside a Room and Stop It from Leaving
Usually, when I talk about soundproofing rooms on this platform, I focus my advice on keeping the noise out. After all, lowering the level of noise in my home is one of my own biggest concerns. However, you may also want to know how you can keep sound inside a room. That’s why I’ve decided that the tips in this article are going to focus solely on stopping noise from leaving your walls.
Before we get right into my advice, we’re going to take a second to understand how sound travels. Understanding a phenomenon is the first step to knowing how to deal with it. Therefore, knowing how sound travels and how you can block it are going to be the building blocks we use to execute today’s mission. So let’s talk about how sound works.
HOW SOUND TRAVELS
The main thing we need to understand about sound is how it travels. Recently, I endeavored to explain whether sound travels up or down in an apartment. It’s a question many people ask to determine whether they should start soundproofing their place from the top down or vice versa.
However, the answer really doesn’t allow for that kind of distinction. Impact noise, the deeper frequencies that are carried through the building’s structure, can be especially hard to defend against. And both airborne and impact noise travel in all directions, as far as their mediums will carry them.
In the case of airborne noise, sound travels in all directions, dissipating the further it gets from the source. Impact noise also dissipates as it gets farther from the source, but it stops when the structure that’s carrying it ends. So, for example, if a bus is making noise, it will also vibrate the ground, which will shake the nearby buildings. But those vibrations stop when they run out of structures that can take over the impact.
Stopping Sound from Leaving a Room
There are also different ways for sound to travel inside of a room, which is what we’re concerned with now. If a room is empty, sound can bounce around freely and cause echo.
For soundproofing purposes, it’s best to let go of any minimalist decorating trends and go all in for bohemian chic. The more soft materials, acoustic foam and fabrics there are, the more sounds will be absorbed before they can bounce or go through the walls.
On the other hand, if you want to block the sound rather than absorb it, you can also do that. We’ll focus on:
- Dealing with structural vulnerabilities around your home, such as doors and windows.
- Plugging holes in your walls, ceilings, and floors so that the sound can’t slip through.
- Adding dense and thick materials to walls and other thin (and therefore vulnerable) surfaces.
- Making sure that structural noise can’t escape the room either, by padding certain areas.
With these goals in mind, I’ve come up with certain steps you can take to ensure that no sound leaves a room.
SOUNDPROOFING TIPS TO KEEP SOUND INSIDE A ROOM
As I’ve mentioned, sound escapes a room incredibly easily if there are vulnerabilities in the structure. So let’s focus on the structure first, and then the other culprits: the doors and windows. Then, we can move on to thickening the walls and alleviating impact noise that travels from the floor. All of these tips are listed in the exact order I’d try them in, to make this easy for even a novice to follow.
#1 Plug Any Holes with Acoustic Caulk
We’ve seen that airborne noise, in particular, is sound that’s just looking for a tiny crack to slip through. Still, before you start slathering acoustic caulk everywhere, there are a few areas you might want to focus on. Here’s what you need to do:
- Get an acoustic sealant and load it into a caulking gun. Even if you haven’t used either of these things before, they’re pretty easy to get a handle on. To make things simpler, I’ve made some excellent product recommendations in the article I’ve linked to.
- Focus on the doors and the windows first. You could test for a draft first, but you don’t really need to. A bit of acoustic caulk certainly can’t hurt. Just line the entirety of where the window or door frames meet the wall.
- Move on to the corners of the room. Again, you can check for cracks, although you’re not likely to feel a draft going through a wall. Cracks in your walls are sneaky that way — they may be hard to spot, but they’re letting out sound like nobody’s business. As I’ve said, focus on the corners of the room and where the walls meet the ceilings and the floors.
- Finally, deal with any obvious cracks in the center of the walls.
#2 Work on the Doors and Windows
Now that you’ve gotten rid of the structural vulnerabilities of the room, there are a few more weak spots to deal with. If you haven’t made the switch from old wooden windows to PVC, you may find that a lot of the noise is leaving and entering through them.
Even if the windows are closed, the frame itself may not be flush against the window. Or, it could be that the glass itself is too thin to be effective. Fortunately, all of these problems have simple solutions.
Weatherstripping tape is going to be your best friend whether you’re thinking about soundproofing your windows or your doors. The thin strip of rubber will help close the gap between the window and the window frame. Most of these products are also self-adhesive, so you should have no trouble installing them.
Next, I’d recommend putting draft stoppers under both the doors and the windows, if necessary. Typically, there’s more of a gap between the bottom of a door and the floor than there is at the bottom of windows. But if you have a significant gap under your window, one that won’t be fixed by weatherstripping tape, you can get a shorter draft stopper online.
If you love DIY projects, you can also make your own draft stopper or even a window plug in a pinch. But this next tip could also be a great help with soundproofing windows, doors, and even walls.
#3 Use Soundproof Curtains and Blankets
By the time you finish plugging the holes in the drywall and dealing with your doors and windows, hardly any sound should be able to escape the room you’re working on. Still, if you feel like you need to do a bit more, soundproof curtains and blankets should do the trick.
Since I’ve already talked about the usefulness of these products many times before, I won’t go through all of that again. I’ll simply leave you with some starting points if you’d like to read more about them.
To start with, you can use soundproof curtains on your windows. If you cover the whole window, they won’t allow as much sound to escape. Additionally, they’ll also completely black out the room. That should be especially helpful if you’re looking for more privacy in general.
A variation on the theme can be found in soundproof room dividers. They’re just as thick and dense as soundproof curtains, but they’re the same color on both sides. So you can use them, as their name states, to divide up areas within a room.
Of course, soundproof blankets are the original soundproofing tool that inspired the previous two. All of these can be put on windows, over doors, along walls, and I’ve even written about how you can do that. Moreover, for extra security, especially if you’re working on thin walls, you may want to put up MLV before covering the wall with soundproof fabric. That should definitely stop any noise from leaving the room.
#4 Reinforce the Walls
If none of the other tips are as effective as you want them to be, your problem may be that your walls are much too thin. In that case, I’d recommend pulling out the big guns. If it were up to me, I’d go straight for the Green Glue and drywall sandwich.
I’ve discussed this tip on previous occasions, so I won’t harp on about it again. Essentially, Green Glue is an acoustic barrier that works best between two hard surfaces. That’s why it would help you a lot to get more drywall, slather the Green Glue on it, and put it up directly over your current drywall.
You’ll not only add thickness and density to your walls but also plug any last cracks that were causing the sound to leak out in the first place.
#5 Make Sure the Floor Isn’t Letting Impact Noise Through
If you have someone living directly under you, you may be concerned with them overhearing you when you’re going about your day. Obviously, you’ll want to get rid of any creaking in your floorboards first. Then, you can pad the floor to prevent your footsteps from making an impact on the building structure and shaking the lighting fixtures in the room below.
I’ve found that soundproof floor underlayments can be a huge help when dealing with soundproofing floors. However, if you don’t want to lift the floorboards, you can also just lay down soft memory foam underlays and cover them back up with your carpets. If you’re worried about more serious impact noise — for example, caused by a machine shaking on the floor — you can even use anti-vibration mats.
#6 Stop the Sound from Bouncing Off the Ceiling
Ceilings are notoriously hard to soundproof. However, I’d say that if you’re looking to stop noise from escaping the room, you might want to attach some foam panels up there. Acoustic foam will make sure that sound doesn’t bounce off the ceiling or pass through it.
However, if you’re having full-blown punk band rehearsals in the room, you may also want to give your ceiling the Green Glue and drywall treatment. Then, follow that up with acoustic foam.
#7 Use White Noise to Your Advantage
While this tip may sound like a bit of a cop-out, I can assure you that it will work if you use it correctly. I’m not talking about playing white noise inside of the room, but rather, outside of it.
If you want the sounds in the room to be completely inaudible from the outside, you can play white noise right outside the door. It doesn’t even have to be loud to work. It will just act as a scrambler to all of the other frequencies, as I’ve explained in other articles.
ON STOPPING SOUND FROM LEAVING A ROOM
Hopefully, you’ll have managed to get your room as soundproof as possible by the third tip. However, you could be dealing with louder and more stubborn noise than these methods can handle. If that’s the case, the next step would be to construct a completely soundproof booth.
Now, I haven’t gone into too much detail on this process because it’s pretty difficult to manage. You’d essentially have to create a room within a room. And, if you want maximum efficacy, you’d need to make the room completely airtight as well. That would require getting a separate oxygen tank and serious construction work.
I’ve talked about something similar in my article on creating a soundproof gaming room. Still, I’d recommend trying the tips I’ve listed here before going completely overboard.