Soundproofing a Room

 Topics Covered in this Article:

Soundproofing a Room is one of the most searched for topics and the subject of many frequent phone calls and emails that we receive at Trademark Soundproofing.

Whether it is a ceiling in a condo, a master bedroom or a home office, people want their privacy and a noise free environment. If you want to reclaim your peace and quiet without having to move to the middle of an isolated field, then invest in soundproofing your room properly. 

This article includes a step by step application guide, with links to more detailed articles for each specific step.

There are 4 basic sound control methods used on the ceiling, walls and floor; utilizing as many as possible will ensure superior results. 

Additionally, good sealing at the perimeters, outlets, doors and windows will prevent sound leakage from these vulnerable gaps.

To achieve all four components you would need to have your room stripped down to the studs. On an existing room you would be able to achieve three of the components as outlined below.

 Component 1 - Walls & Ceilings:

Insulation / Absorption: Your walls / ceiling need insulation in them to absorb some sound.

Applying fiberglass into studs to soundproof room wallsIf your studs are exposed wrap, your electrical outlets with Acoustical Putty Pads.

 Then insulate using Fiberglass Batt Insulation or Mineral Wool in between the studs. Wrap your HVAC with Duct Wrap.

If your drywall is in place and you do not want to remove it, you can insulate by pumping Cellulose into the walls.

Your HVAC vents should be lined with duct liner.

Decoupling: Your walls / ceilings need to be decoupled to prevent soundwaves from passing through the structure.

Apply Resilient Sound Isolation Clips to Walls to Decouple to Aid in Soundproofing a RoomIf your studs are exposed, you would want to decouple your drywall from the studs by using Resilient Sound Clips on the face of the studs.

If your drywall is already in place and you do not want to remove it we recommend not to decouple the wall. See our article regarding the Triple Leaf Effect.

If you are trying to control footsteps or impact sounds coming from above then decoupling the ceiling is a must. 

Damping and Mass: You want to add weight to your walls / ceilings / floors  and you want to damp them. Damping dissipates any soundwaves hitting the structure and stops it from traveling through and down it.

Apply Green Glue Noiseproofing Compound to Walls to provide damping for soundproofing roomsThe most effective way to accomplish this is by applying a second layer of drywall with a damping compound like Green Glue Noiseproofing Compound in between 2 layers of drywall or 2 layers of subfloors.

If your sound issues are coming through the walls and you are damping the walls, we strongly recommend adding a 2nd layer of drywall and Green Glue to your ceiling as well, since sound can flank over your walls and come through your ceilings.

This is a must in situations where there is an open air space above both rooms e.g. an attic or crawl space.

Finishing / Sealing:

Applying Acoustical Caulk to perimeter of walls and ceilings to sealFinally, be sure to seal the perimeters of your walls and ceiling with a proper Acoustical Caulk.

In addition, seal around all electrical outlets by adding our Acoustic Electric Box Seal.

Utilizing insulation, decoupling, mass and damping all together gives you the highest soundproofing performance, usually 30+ STC points over a standard wall/ceiling.

Utilizing insulation, mass and damping will give you solid sound control usually about 80% noise reduction if done correctly.

For more detailed information on the steps listed above:

  • If you prefer to work with your existing walls then we suggest reading our Soundproofing Existing Walls and Ceiling article.

  • If you want even better soundproofing and are ready to remove the existing walls/ceilings or are doing new construction then read our How to Soundproof article.

 Component 2 – Floors:

How to Soundproof a Floor with New FlooringNew Flooring: For new construction, use insulation in floor joists, Joist Gasket Tape on the top of the joists, and 2 layers of 1/2” subflooring with Green Glue Damping Compound in between.

You can cover with a Rubber Underlayment before installing your final floor.

For more details see our How To Soundproof Article.

 

Apply premium carpet underlayment to soundproof under carpetsCarpeting: If you have existing carpets or you are putting down carpet our Premium Carpet Underlayment is an excellent noise blocker and can be installed in place of a carpet pad. If possible try to add a 2nd subfloor with Green Glue first

Hardwood Flooring: You can install Rubber Underlayment under your hardwood floor.

If you have a finished hardwood floor and would like to stay with that, then there is not much you can do other than working on the ceiling below.

 Component 3 – Doors:

Doors are thin / hollow and have gaps around the perimeter, allowing for lots of noise penetration. Ideally swapping to a solid wood door will give you a good start.

Soundproofing components for doors includes:

Apply Soundproofing Rubber below the molding surrounding the door frame to soundproofMoulding: Stuff Soundproofing Rubber and Acoustical Caulk between the frame and wall.

Door Panel: Then install a Soundproof Door Panel which will beef up your door and seal the gaps at the edges.

Alternatively, you can use a 1/2” thick MDF board over the door, applied with Green Glue Compound sandwiched in between.

Perimeter Gasketing: The jambs and headers should be sealed with a Soundproofing Door Gasket or Soundproofing Weatherstrip.

Door Bottom: Most importantly, the large gap at the bottom of the door needs to be sealed with a Sound Rated Automatic Door Bottom.

 Component 4 – Windows:

Windows are another weak link in the room envelope in regards to sound control.

Various soundproofing options include:

Secondary Window: One option would be to install a second window behind / in front of your existing window. 

Vision Lite Kit: If you will not need to open or close the window you have the option of installing our Acoustic Vision Lite which is an excellent kit, providing a strong seal around the perimeter. It is easily installed and allows for you to add your own thick pane of glass.

Apply Sound Barrier Window Curtain for Sealing Windows and Soundproofing RoomsSoundproofing Curtain: Another practical, very effective solution for windows is to use a Sound (and Light) Barrier Curtain. We custom size your curtain and it is available in a variety of colors. Installation can be done with velcro or grommets and pegs.

 Soundproofing Solutions for Today's Designs:

A final issue that often arises is the sound traveling in a home itself e.g. talking on the first floor can sometimes be heard in a bedroom on the 2nd floor.

This is usually a problem in newer homes where the style is to use hardwood and tile throughout the home with wide open foyers and a modern sleek look that minimizes curtains and oversized furniture. This type of design will cause sound to reflect off the hard surfaces thus easily and loudly traveling throughout the home.

Our suggestion is to soundproof your doors paying close attention to the gaps at below or above.

Apply Acoustical Fabrics in your home to soundproof roomsThen install Acoustical Panels. You can order panels in virtually any color / design fabric to match your decor (you can even have panels customized with your own photos, paintings etc). These panels are hung in your hallways, on stairway walls and other strategic locations to absorb sound waves and stop them from echoing off your walls.

As you can see, sound control doesn't have to be complicated if you have the right Soundproofing Products and guidance! At Trademark Soundproofing, we pride ourselves in offering our valued clients a wide array of top-quality products for every type of application along with our Trademark Customer Service.

 

Customers Questions and Answers

1) Bud: Our bedroom wall is about 20' from our neighbors Heat Pump and pool pump. His house is brick - our house walls are 6" studs with fiberglass insulation with Masonite with vinyl siding on top and sheet rock on the inside. We have several storm windows (3) which I have installed 2 layers of plexaglass about 3/16" thick. His pool pump runs 12 hours a day and is getting quite loud. There is a fence between the houses which I recently rebuilt using 1/2 particle board then fiberglass insulation then 1/2" particle board then the standard 1/2" pressure treated pine fence material. The sound comes over the fence and some through it - into our bedroom and our back porch which we spend lots of time on. I figure my options are 1. to offer to buy him a smart pump which is very quiet which will be installed about $1000 or 2. try to put something up on my side of the fence to reflect or absorb the noise. The fence is ~6' so would assume would need to be higher than that with maybe the top portion angled to reflect the sound back toward the pump. I know that this is peanuts to what you all do but would appreciate any suggestions. Thanks,

Trademark Soundproofing Reply:

Hi Bud, If a new pump would do the trick you may want to consider it as soundproofing your fence is not that cheap. Take a look at our exterior Sound Barrier Curtains and you would want your fence to be at least 8 feet tall (Keep in mind it is still an open air space above your fence).

2) Ernest: Hello, I currently live in a townhouse (in Canada), with one shared wall, including one side of our master bedroom. On occasion, we can hear our neighbours talking in the next room (very faint mumbling, but we cannot make out what they are saying). We also hear heavy footsteps on the rare occasion. I had a local contractor come do an assessment. When we drilled a hole, we found fiberglass as insulation between the concrete wall and drwall. When we took a look at the attic and found that there was a sheet drywall separating our units. From a building code perspective, I would assume that the concrete wall goes all the way to the roof. The insulation in our roof is also fiberglass. The contractor suggested adding a 5/8 in drywall with Green Glue for the shared wall. He also suggested adding cellulose to the roof. With regards to the thumping and lower frequencies, I would like to know if there is merit to decouple the roof with sound clips? I am also open to any suggestions you may have to make the optimal mitigation strategy. Thank you for your help. Ernest

Trademark Soundproofing Reply:

Hi Ernest. I agree with your contractor that adding a 2nd layer to your with GG makes the most sense for your situation. I would do the same thing to your ceiling in order to stop sound that is flanking through the ceiling. You will have a hard time stopping the heavy thumping sound as that is most likely coming through the floor.

3) Ernest : Hello, Thank you for your insight. With regards to the roof, I would like to clarify that we are adding drywall + GG along the entire roof surface? Or just a portion of it? Should I do anything to add insulation to the roof (e.g. cellulose vs. fiberglass)? Regards, Ernest

Trademark Soundproofing Reply:

Add to the entire ceiling of the room or rooms that you are having the noise issue in. If there is sufficient Fiberglass in the ceiling, then you can leave it alone.

4) Emil: Hello, I've just renovated my apartment and I was trying to reduce noise from my neighbors, however I fear I might have messed up. It is a concrete building, so in the living room to reduce noise from downstairs neighbors I put "pressure resistant" insulation with fiberboard on top, as a floating floor. On top of the fiberboard I also have one layer of sheetrock and then the wooden floor. Sadly I am experiencing a "booming" sound when walking on this floor now, like a drum. It's surprising to me as I thought the insulation would be dense enough to absorb any sound. I was recommended this procedure when talking to professionals about sound-insulating a floor. I was wondering if someone could explain to me what is going on with this floor? Triple-leafing effect should not occur as to my knowledge there would be only one airspace in this floor. Concrete + airspace/insulation + fibreboard + sheetrock. Have this floor actually made it worse? Making the noise from my neighbors resonate? *** I also insulated the wall. 2x4 on the wall with insulation in between, then a layer of sheetrock. Did this also worsen the situation? The wall was originally just concrete with wallpaper on it, as you can see in the photos. So I'd appreciate if you professionals at TMsoundproofing could try to explain to me what has gone wrong with this renovation process.. As for the wall - Should I just have used sheetrock straight onto the concrete with no wooden frame?

Trademark Soundproofing Reply:

Hi Emil, I am not sure what "pressure resistant" insulation is, however that seems to be the culprit here. It is probably acting as a very thin air space thereby causing that resonance that can amplify certain frequencies and give you that hollow ring when you walk on it. We would have recommended going with a "heavy" floor with layers of damping compound in between. If you want to create a floating floor you should to that with proper framing on rubber joist isolaters with fluffy insulation between the joists. As for your wall we would recommend that you frame a new wall to allow for a larger air gap which can be filled with insulation then double drywall and Green Glue. You can decouple that wall from the concrete with these specialized resilient sound clips.

5) Emil: Hi, Thanks for your reply. The "pressure resistant" insulation is a 50mm high density compact rockwool. I had no particular wish to make a floating floor, but I was advised to do so by some other sound professional. Is insulation the same as an air space? You say you would have recommended a heavy floor. Would that be to put several layers of sheetrock and green glue directly on the concrete slab? I live on the top floor with neighbors underneath me, that is the airborne sound I am trying to eliminate. As for the wall, I cannot build it out any more into the room. Would you then recommend removing the joists and insulation completely? Have I actually made it worse with this setup?

Trademark Soundproofing Reply:

It is the same as air space except that it also absorbs some sound energy. On the floor I would recommend layers of plywood rather than drywall. You can leave the wall just add another 1 or 2 layers of drywall with the Green Glue in between.

6) Emil: I could leave the wall, but would the wall be better without the airspace? Have I made it worse than nothing? It sounds like it

Trademark Soundproofing Reply: No. It is not worse as it will help from many frequencies. On the floor it may have contributed to the hollow ring you get when walking on it.

7) Emil: Thank you for your help on the subject as I am inexperienced. Could you not argue that the airspace in the wall has accentuated and made louder some frequencies? Music for instance. It feels like I can hear my neighbours even more now, but maybe my mind is playing tricks on me

Trademark Soundproofing Reply: Yes a small air space can resonate and amplify certain frequencies, however it will also help on other sounds. If you find that it is precisely the frequency that you were trying to block that is being amplified you may want to take your wall done. However adding more weight and damping to the wall should help without removing the wall.

8) Nathan: I am now starting my home soundproofing project that I was researching in November. I?ve gently taken the existing drywall down in the room I?m going to soundproof. My question is, before I put in batt insulation between the studs, would it improve the STC if I cut the old drywall in lengths that would fit between the studs and then attach it to the inside of the drywall in the adjacent room? (It?s one way to recycle and repurpose this perfectly good drywall.) And would this additional amount of drywall work better for sound damping if I ran a bead of acoustic caulk around the perimeter of each piece? Nathan

Trademark Soundproofing Reply:

Hi Nathan, Good idea if you have extra drywall. Don't bother with the caulk. Green Glue between the layers will help.

9) Nathan: Thank you for your answer about adding extra drywall. I know Green Glue isn't technically glue, but will it provide enough adhesion by itself to hold the drywall in place over time? Otherwise I could secure it mechanically with something to prevent it from moving. Nathan

Trademark Soundproofing Reply: It will not. You must use mechanical fasteners as per local code ordinance. You will actually get better performance that way as the Green Glue needs to be tightly compressed between the 2 layers. Thank You

10) Nathan: Thank you for your willingness and time to answer my detailed questions. I'm now considering a different soundproofing project in our house. I'd like to do as much as possible to soundproof the indoor mechanical closet (next to the bedrooms) where the HVAC air handler is. I plan to use joint gasket tape under two layers of drywall (with Green Glue) on the inside of the closet walls and ceiling. Also joint tape under the wooden floor if I can. Two questions: What can I do to reduce the vibration/noise of the fan/motor especially through the floor of the plenum? And what is the best insulation to use between the studs in order to further dampen the sound transfer? Since it is a relatively small space and I wouldn't be buying a lot, would recycled cotton batt be more effective than fiberglass batt? Thanks, Nathan

Trademark Soundproofing Reply:

Hi Nathan, We do not see any head to head testing showing that one insulation is better than the other. Therefore we usually just stick to fiberglass batts for the cost savings (stay away from spray foam). We will have a sheet metal damping compound available in another 2-3 months, for now I can only suggest using duct liner.

11) Richard M: Hi, We moved into a new construction home with all hardwood floors. Unfortunately we weren't prepared for the hollow floors/walls to transmit so much sound! I don't think it's financially feasible to do the entire house, but I'd like to know if it's possible to add another layer of ceiling below the master bedroom (so we don't rip out the flooring), coupled with adding door insulation, to improve the situation? Thank you.

Trademark Soundproofing Reply:

Hi Richard. It is definitely possible. You can add another layer of drywall with Green Glue to the ceiling below, however I would suggest that you blow in insulation first if you want good results. The door is very important in bedrooms and lots of sound gets in there. Please see our How To Soundproof a Door article for proper door soundproofing. Thank You,

12) Richard: What kind of blown insulation do you recommend? Open cell foam or blown cellulose (wet). Thank you, Richard

Trademark Soundproofing Reply:

Blown Cellulose, wet or dry. We do not recommend any type of spray or injection foam

13) Rebecca D: Hello, I have a soundproofing issue. We turned a bedroom into a studio apartment. The double wood doors to enter the room from the rest of the house is where the sound is coming through. We put additional double wood doors up and there is about a 1 1/2 inch space between the doors that I want to put some material to reduce and dampen the sound coming through the doors. What do you suggest

Trademark Soundproofing Reply:

Hi Rebecca. Please see the Door Astragel here. Thank You

14) Rebecca D: Thank you for getting back to me. I didn't explain my situation very well. I have blocked off a room from the rest of the house. It has a separate entrance and we have rented it out. The place where the room meets the rest of the house is a double door that will not be used to enter or exit the room. We have locked the double door from the inside of the rental so that we cannot access that room from the rest of the house. In addition, we put another double door next to it that is locked from our side of the house - the renter cannot access the rest of the house through this door. So, there is a double door, a space that is 1 1/2 inches of airspace and then another double door. It is this 1 1/2 inch airspace that is the size of the double door - 78" high and 66" wide that I want to fill with something to cut down on the noise that comes through the doors. I was thinking that drywall with green glue in-between two pieces cut to fit the entire space would be best. What do you think? In addition, I was thinking of affixing a rubber seal around the edges to complete the seal. I appreciate your comments. Thank You, Rebecca

Trademark Soundproofing Reply:

Hi Rebecca, If you plan on not using the doors anymore than you can actually attache 1 or 2 layers of drywall to the doors with Green Glue in between. If you want something that you can take on and off you can consider our custom made door sound control panels here. Thank You

15) Vlad Z: Hi, I am planning to soundproof existing party wall in semi-detached house from my side (to reduce noise coming from neighbor's side) and because most likely cannot do demo, so considering laminating over existing drywall (with green glue) either with 1 layer of 5/8" gypsum board or 2 layers (and additional green glue of course). Existing wall is 16" o.c. wood studs, insulation and single layer of drywall. Can you please advise if second scenario (2 layers and additional green glue) make noticeable difference compare to first scenario (green glue and single layer of new drywall), approximately how many STC points in each scenario? Thank you! Vlad. P.S. What is standard shipping time for GG delivery to Staten Island, NY?

Trademark Soundproofing Reply:

Hi Vlad, The 1st layer of drywall with GG will give you about 9 STC points. An additional layer with GG will give you about another 4 points. Keep in mind that if you share an attic over the wall you would need to treat your ceiling as well. Orders by 1 pm ET usually ship same day and arrive in NY the next business day. Thank You.

16) Scott F: Good Afternoon, The flooring for the second story in my house is one-and-a-half inch T & G pine boards. The bottom of these boards is also the ceiling of my first floor (so no joists, etc.). I was thinking of putting Green Glue or MLV down, and then a layer of 5.5mm underlayment. On top of that I will put 1/2 inch carpet pad and carpeting. Will this work for drastically reducing upstairs noise being heard downstairs? If so, which would work better, the Green Glue or the MLV? Thanks for answering my questions. Scott Franklin

Trademark Soundproofing Reply: Hi Scott. The GG would be better. Being that you do not have a decoupled ceiling below with some absorptive insulation in between you have to have realistic expectation. You will have a decrease in the upstairs noise however I do not know if it will be as "dramatic" as you are expecting. Additionally in your scenario you may want to go with a thicker rubber underlayment 8 or even 12 mm (we have the 12 mm avail via phone call or email to our sales office). Thank You

17) Joe M: I have a problem. I have 99 3/4 inch high walls, but I'm dealing with 96 inch drywall sheets How do I go about soundproofing the rest of the wall? I'm about ready to soundproof one wall.

Trademark Soundproofing Reply: Hi Joe. You can cut strips of drywall for the other 3.75". You have to cover the entire area properly if you want to achieve good sound control.

18) Robert M: In the master bedroom of our town home , we are hearing unintelligible voice sounds and TV noise from the adjoining neighbors master bedroom. The existing construction is: В· 5/8 drywall В· R-13 fiberglass insulation В· Firewall В· ВЅ air space В· 5/8 drywall В· R-13 fiberglass insulation В· 5/8 drywall The attic areas are separated by the firewall which extends to the roof. 1. What kind of STC improvement should I expect from adding Green Glue and another 5/8? drywall to the existing drywall? 2. Would there be any advantage to substituting sound board (e.g., Silent FX) rather than using 5/8? drywall? 3. If so, what sound board would you recommend? 4. Do you know of any contractors in my area (zip: 61615) with experience in such soundproofing?

Trademark Soundproofing Reply: Hi Robert, You can expect a 5-9 point STC reduction. There would be no advantage with the soundboard. Thank you.

19) Robert: What kind of STC improvement should I expect with another layer of Green Glue and wallboard?

Trademark Soundproofing Reply: Slightly less than with 2 layers of drywall about 1-2 STC.

20) Eric S: I'm doing some research on what materials I need and how much. I have a condo that was built in the 70's. The sound proofing doesn't seem all that well since a new neighbor moved in about 8 months ago. I inspected some areas. One good thing is the common wall to an adjacent unit is a double wall. However there is no insulation. I plan to use insulation and double 5/8 drywall with Green glue. The floor system between my first and second floor is a 2x4 open truss design. I cant tell the spacing but it appears greater than 16". The height appears 16". its hard to tell but it appears hollow all the way to the adjacent unit. I suspect this is why I get some flanking sound already. I have a pretty good idea what I need to do as far as green glue ceilings and walls. However, how is it best to sound proof my bathroom and kitchen. The kitchen I have cabinets hanging on the wall. I plan to redo the walls with double 5/8". If I decide to tile and use rockboard, is green glue still effective? This question also applies to the bathroom. And as far as insulating the truss system, I plan on hanging the 1st floor ceiling drywall first, then just laying fiberglass batts between the floors just for sound dampening purposes. Is this effective enough? Do I need to close up the open air space that continues to the adjacent unit? Thank you

Trademark Soundproofing Reply: Hi Eric, As long as the Green Glue is applied between the 2 layers of drywall it will work well after you install the cement board and tile over that. For ceilings, it depends, if footsteps is your concern than you should hang your drywall from resilient sound clips and channels. If there is an open attic between you and your neighbor that must be closed off by either extending the wall all the way to the roof line or soundproofing your ceilings.

21) David K: I have a wall in my duplex that separates the two kitchens. The noise level is quite high from side to side. If I were to remove the drywall on one side, insulate and add hat channel and clips, with new drywall, would I still be able to hang cabinets on that wall, or would the weight of the cabinets be too much for it?

Trademark Soundproofing Reply: Hi David, It is possible however we would recommend that you use clips every 24" and channels every 16"OC for that wall and be sure to screw the cabinets into the channel only.

22) Ryan C: Hi. Reading all of these Q&A's leaves me jealous. With the military I will not be able to permanently reside in a location for approximately 10 years and thus I am stuck living in apartments. I like to work out to loud music and I am hoping to get a microphone and amplifier for electronic instruments - point being I would like to keep my sound to myself. If possible, I was hoping for guidance on what sorts of apartments I should be looking for, and maybe different price ranges that I should expect to incur for different degrees of soundproofing (i.e. xxxx$ for a LxWxH room with Z% of soundproofing - a few scenarios would be fantastic). Sorry if this is a strange question, and thanks so much.

Trademark Soundproofing Reply: Hi Ryan. That is a tough question. Best is to ask if the apt has the minimum of insulation between walls and ceilings for sound and if any extra's were done for sound control. We appreciate your service!

23) Willie: Hello there, i am an aspiring sound mixer and like to mix my music super loud (with a giant sub) unfortunatly my living space does not permit this level of noise. I would like to soundproof my room as much as possible and then after that acoustically treat the room to control the sound reflections. is this possible? or will the soundproofing deaden the room so much that acoustic treatment wont make a difference or be ineffective. is there anything that i can do to create a great mixing environment as well as soundproof my room heavily?

Trademark Soundproofing Reply:

Hi Willie, Sound proofing/damping the walls will not effect your ability to acoustically treat the walls afterwards with acoustic panels etc in any way. If anything it will enhance the acoustics of the room as well.

24) Sue W: Do you have an installer in Livonia, MI.

Trademark Soundproofing Reply: We have a contractor in Dryden, MI. Give us a call and we can give you his contact info.

25) Jamie: Hi there, I am looking into soundproofing options for a meeting space in our office. Our building was designed as a home and the room has wainscoting. What are our soundproofing options that won't require the removal of our drywall and the wainscoting? Unfortunately, sound panels aren't able to be used as most of the wall space is being used.

Trademark Soundproofing Reply:

If you don't mind covering the drywall and wainscoting then you can use Mass Loaded Vinyl to cover the entire wall. Otherwise best you can do is treat the doors. https://www.tmsoundproofing.com/How-To-Soundproof-a-Door.html

26) Ken: Hi there! I will be soundproofing a basement room for use as a vocal recording studio. I will be building decoupled walls encapsulating it, and using resilient channel + clips on the ceiling. All surfaces will be covered with 2 sheets of 5/8in drywall with green glue between them and well insulated between joists/studs. Will adding mass loaded vinyl anywhere in the construction make an appreciable difference on outside sound penetrating into the space? I have read that it would have minimal impact on the decoupled walls and on a resilient channel ceiling. Any insight on this? Thanks!

Trademark Soundproofing Reply: If you add it directly to the joists and install the clips and channels over it, it will definitely enhance the soundproofing.