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I want to create a permeable (allowing things to pass through) sound barrier (noise barrier, soundwall, noise wall) for soundproofing purposes. It is for a room and specifically for the doorway/entrance (without a door).

Type: Standard Doorway
Height: 80”
Width: 36”

Criteria:

  • The sound barrier should be permeable. I can walk through the sound barrier.
  • The solution should not make noise itself. (maybe it can be faint like a desk fan on low speed so it doesn't disturb)
  • It should block noises/sound coming from outside the room to a certain degree (music, people talking/walking/doing mundane activities, distant sounds coming from outside the building)

I'm not very knowledgeable in acoustics but I believe the barrier should block sound between bass and higher midrange in audio frequency spectrum. (You can correct me if you know better or based on what is possible)

Bass: 60 – 250Hz
Lower midrange: 250 – 500 Hz
Midrange: 500 – 2kHz
Higher midrange: 2 – 4kHz

Any ideas/technological solutions on how to create this permeable soundproofing barrier/system?

Note: Just to be more clear, it is a hole. It is a doorway without a door, an entrance, an opening. It is a permeable sound barrier (soundproofing) for a hole/opening basically. I thought there could be solutions with active noise cancelling or through certain sound waves/mechanical waves/electromagnetic radiation etc. Also, soundproofing the hole/doorway might be part of a bigger system.

ermanen
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  • I’d look into HVAC soundproofing systems. We use materials to baffle the air movement as it passes through the ducts. The baffles keep the noise in the heating unit from entering the room. – Lee Sam Jan 11 '22 at 17:15
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    Noise-cancelling headphones? – MonkeyZeus Jan 11 '22 at 17:23
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    And what is your budget for this? $50? $50,000? – Ron Beyer Jan 11 '22 at 17:24
  • @RonBeyer Any solution that fits the criteria (with some flexibility) is acceptable. I imagine it can be expensive but there can be clever and cheaper solutions. – ermanen Jan 11 '22 at 17:26
  • Build an anechnoic chamber with a door. – Ron Beyer Jan 11 '22 at 17:29
  • @MonkeyZeus Yes I know them but it is not the solution I want. It is difficult to use them for long periods also. – ermanen Jan 11 '22 at 17:30
  • @RonBeyer I know anechoic chambers but I want a permeable solution. It is the main part of the question. Is it possible to create a permeable anechoic system? – ermanen Jan 11 '22 at 17:33
  • Yes, they have to get into/out of them somehow. They can be vented... – Ron Beyer Jan 11 '22 at 17:35
  • @LeeSam I don't know much about HVAC soundproofing systems. Is it permeable? If you know the details, you can provide an answer. However, it seems like it is contained in a soundproof room: "The goal with these HVAC soundproofing treatments is to contain the noise to within the room and protect against the bleed of the noise out." However, I couldn't find info about baffling the air movement. – ermanen Jan 11 '22 at 17:40
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    Look into how the sound room in a recording studio is isolated. That kind of room is designed to keep outside noises out so they don't get into the recording. Yet it is permeable, too, as there are passage doors for people and instruments. You will be looking toward the higher price range for this, but the results should be good. Note that if by 'neighbors' you mean 'apartment neighbors' (ie you rent) you'll be limited in what you can do. Consider making a smaller "sound room" inside one of the rooms you have available. – Triplefault Jan 11 '22 at 17:54
  • Perhaps we need to clarify the condition "I can walk through the sound barrier." If this means opening a door, then fine, we can deal with soundproofing doors [& walls & windows]. If it means literally nothing to impede, just a walk-through 'hole', then see my answer below. Soundproofing requires **mass**. Nothing else is a substitute at anything below 250Hz or so. Top end is easy to filter out, low end is not. – Tetsujin Jan 11 '22 at 17:58
  • Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/133136/discussion-on-question-by-0-how-to-create-a-permeable-sound-barrier). – BMitch Jan 12 '22 at 18:39

2 Answers2

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You cannot soundproof a hole.

HVAC silencing systems work by turning so many 'soft' corners that a sound that was fairly quiet in the first place can't make it down the length of the baffling before it is absorbed. Some of the air is lost in this & a corresponding boost needs to be applied at the origin.

As you can't baffle your doorway or windows in anything like the same way, you cannot soundproof them.

Tetsujin
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Install a door in the opening with sound proofing material in and on it.

Your hole remains "permeable" - the door will be on hinges so you can open it to pass through, yet it will be as sound proofed as you care to make it by filling the door with soundproofing material and applying additional material on the inside and outside of the door itself.

Actually, just installing a door (and closing it) will cut down on the amount of noise moving through the "hole". The door itself may be sound proofing enough for your needs.

FreeMan
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  • +1 for suggesting just starting with the door. – Lee Sam Jan 11 '22 at 21:55
  • @LeeSam - OP clarified no door in the comments. They're looking for a force-field ;) – Tetsujin Jan 12 '22 at 13:39
  • And that, as noted many times, @Tetsujin is why critical information should be in the _question_ not in the _comments_. Either that was added as a comment after I posted my answer, or I just never saw it buried in the comments. I agree, is seems that the Get Smart "Cone of Silence™" is going to be the only thing that satisfies the OP. He'll have to wait for it to be invented or move into the movies. – FreeMan Jan 12 '22 at 13:43
  • @FreeMan - indeed; this appears to be a request for a force field of some sort. In fairness the OP did add clarification to the question shortly after my comment requesting it. – Tetsujin Jan 12 '22 at 13:57