sometimes I dream about sleeping well...

[gusl]

I suspect that a thick layer of water would make a good sound shield. I don't know where this intuition comes from.

Comments

[ernunnos.livejournal.com]

Water transmits sounds very well, because it's incompressible. You want something that has a lot of internal friction, to convert the energy of the sound into heat.

Have you considered studio foam? If you buy it from a pro-audio supply store it's horribly expensive, but you can get it on eBay about $1/square foot. I bought some for my living room shortly after moving into my house, so it's been about 6 years, and I see the same company is still in business. You might try ordering a pack and using it to cover a 6x8 privacy screen, then set it facing your doorway. The direct sound from the hallway would be largely absorbed, and it would also damp much of the reverberation in the room. Corner blocks and more tiles along the wall near the corner are also surprisingly effective. Sound gets focused there, so even a single tile on one of the three walls can have a large effect.

[gustavolacerda.livejournal.com]

The sound is coming from above. I live in a basement.

[ernunnos.livejournal.com]

How big is the room? Do you have a drop ceiling? If you do, just take the existing panels down and stuff some insulation in the space. If not, you could either install one with acoustic tiles, or glue foam directly to the ceiling.

[gustavolacerda.livejournal.com]

I don't. Gluing the foam onto the ceiling seems likely.

My problem are the thumping, low-frequency footstep sounds (probably peaking around 100-200Hz). Would I glue the foam normally, or upside down (since I'm trying to stop incoming sound, not outgoing sound)?

[en-ki.livejournal.com]

Curiously, the internet claims footsteps are lower in frequency than that. Even at 100-200Hz, though, the waves are 5-10 ft long and not at all directional, so I bet you would need more foam than is reasonable to dampen it substantially.

[williamallthing.livejournal.com]

buy your upstairs housemates/flatmates/neighbors a beautiful rug and ask that they place it above your room.

[gustavolacerda.livejournal.com]

My idea was that the sound would bounce off the surface of the water. Just like light does, from a big enough angle.

[zarex.livejournal.com]

Water itself is somewhat less effective in blocking sound as the solid container you'd hold it in.

[stepleton.livejournal.com]

Placing your bed under a giant plastic water sac* sounds like
* installation art at best
* a hilarious and bizarre setup for water damage in the middle (don't take up knitting!!)
but perhaps to underscore the hazard for which you would be going to such great effort and expense, I recommend that you introduce it to houseguests as "The Midnight Smotherer." Seriously, if a cable or support breaks, the BEST case is that you get wet; the worst case is that you are trapped under a whole lot of plastic secured over your face and body by hundreds of pounds of water. Do not make this thing unless (a) you plan on sleeping with a 5"+ hunting knife under your pillow (b) you're reasonably certain your arms wouldn't be pinned down by the plastic (c) you're confident in your ability to wake up, recognize that you're a couple minutes from death, and be ready to slash your way to freedom. If you have sleep paralysis, then this is not the sound dampening strategy for you.

OR

Get the studio foam. Seriously. I think that putting any kind of foam, or heck, even an enclosed air gap between your ceiling and you would be more effective than you think. Part of the reason people have drop ceilings is to block sound from upstairs---of course if you already have a drop ceiling then it may be a tougher problem than it sounds right now.

* I don't know what the black lines in your drawing represent, but even if you plan to use some rigid shell to form the dome, you'll probably be using some kind of watertight bladder (i.e. sac) to actually hold the water. And if you can afford to make a shell strong enough to ensure that you won't be smothered, you can afford to build an ordinary non-deadly anechoic chamber around your bed, which will work just fine and be lighter and less messy to boot.

[stepleton.livejournal.com]

It occurs to me that you could mitigate the smothering hazard somewhat by building a kind of "water igloo", which is to say, use lots of smaller bags filled with water. The low-rent way to do this would be to arrange a "fort" of milk crates around the bed and stack the water inside the crates. Put a sheet of plywood over the top and stack water bags on top of that too. Could be a lot safer, but still I don't like the idea of sleeping around a lot of plastic bags filled with a heavy, easily deformable substance. Also, you could get wet, damage books and other belongings, etc.

[stepleton.livejournal.com]

Well, I guess all igloos are "water igloos".

sleep paralysis

[gustavolacerda.livejournal.com]

aha! I'd been wondering if sleep paralysis was scientifically verifiable. Apparently it is.

[gustavolacerda.livejournal.com]

However, Wikipedia says that stimuli such as light or sound trump sleep paralysis. I imagine touch is no exception.

[qatar.livejournal.com]

It says they may; from my own experience, they don't always.

[parentheses.wordpress.com (from livejournal.com)]

"Do not make this thing unless (a) you plan on sleeping with a 5"+ hunting knife under your pillow"

:-D

[kvschwartz.livejournal.com]

Also, having a large container of water over and all around your bed as you sleep presents that whole drowniness issue, should said container suffer a catastrophic leak.

[easwaran.livejournal.com]

I believe that sound passing between air and water loses a great deal of its energy. I recently saw a special on the Discovery channel about hippos and their communication abilities. They claimed that they're the only species that simultaneously communicate in the water and in the air - they make funny dolphin-like clicks and squeaks underwater while their nostrils make more hippo-sounding noises in the air. Other hippos hear the nostril noises through the air, and the clicks through their jawbones. But even though both sounds were quite loud, you could only hear whichever one was in the same medium as the microphones.

[gustavolacerda.livejournal.com]

Great! Now I need to find a practical way to test my idea.

[easwaran.livejournal.com]

I think the substance used at the interface might be important though - the underwater sounds the hippos (and dolphins) make I think are originally generated in air, but they have some sort of organ with appropriate density to somehow make it transition nicely into the water (and vice versa so that they can hear underwater sounds well). But I think you have to design something very carefully for it to transmit well across media like that. I think.

[kvschwartz.livejournal.com]

My presumption would be that sound loses a lot of its energy each time it has to pass from a medium of one density to a medium of a very different density.

Thus, for example, a high-insulation compound window comprising layers of air and glass should be able to block a lot of noise even if said window is not all that thick.

[en-ki.livejournal.com]

The model for this I have in my head: every transition reflects some of the sounds and refracts the rest, so you would expect a fair bit of it to bounce away from you, self-interfere, etc.; more if the transitions are at a variety of angles.

[peamasii.livejournal.com]

[gustavolacerda.livejournal.com]

sensory deprivation tank? I prefer to be dry when sleeping.

how do you avoid drowning in these tanks?

[peamasii.livejournal.com]

hold your breath? i'm not sure

[en-ki.livejournal.com]

They're very salty, so it's easy to float.

[lordspaz.livejournal.com]

Earplugs.

[gustavolacerda.livejournal.com]

I tried them twice: Wed/Thu and Thu/Fri nights.
First night (foam plugs): not effective. I woke up with the noise regardless.
Second night (waxed ear canals shut): they had the side-effect that I woke up >3 times throughout the night, for no apparent reason.

[parentheses.wordpress.com (from livejournal.com)]

Did you wake calmly or in a fight-or-flight state?

[gustavolacerda.livejournal.com]

calmly, as if I'd never fallen asleep in the first place.
I suppose I can't sleep deeply with earplugs.