Noise Reduction

[keith.lamothe]

Had a question for y'all, as I figure every specialty is represented somewhere in our audience

My family recently moved and I'm still adjusting to the work environment that's possible in the new place (I'm quite sensitive to noise distractions).  It's been a dramatic improvement in lower from-outside-the-house noise but there's not really anywhere in the house I can avoid hearing our 4-year-old and 1-year-old tromping about while they're inside.  We're looking into various options for increasing the sound absorption of the house and whatnot but I'm also looking at more direct noise reduction.  For years now I've used these really awesome earplugs (http://www.earplugsonline.com/ , rated NRR 34) and they're a big help, and I typically wear earphones over them and listen to music (currently using some noise-cancellation ones I received as a gift, pretty nice).  I was wondering if there'd be a point in using noise-reduction earmuffs like are used on firing ranges, construction sites, manufacturing lines, etc.  Any of y'all know if there's a point in stacking, say, 24 NRR earmuffs over 34 NRR earplugs?  Or is it into really diminishing returns at that stage?

Thanks

[Cyborg]

You are not going to achieve complete noise reduction because part of the sound that goes into your ear actually passes through the skull, not just your ear itself. Lots of the headphones and earplugs only block the direct canal, and only passively. If you are looking to get real noise reduction, you want to look at noise canceling devices, which generate an oppositional wave to the incoming annoyance.

The best thing you could do is move your workplace to the top floor, the play area to the bottom floor so as to avoid low-frequency noises such as stamping on the floor. Combine that with the noise canceling, and you should be all set. If your question is, do they stack, sort of. But not in the way that you think because like I was telling you, skull sound absorption is nearly unavoidable without a chamber.

[keith.lamothe]

Ok, thanks for the info.  That's basically what I figured: if it doesn't come in the "door" (canal), it just goes around it.

It's a one-floor house; previously we were in a two-floor and I worked upstairs but it was right on the stairwell so the high-frequency noise would come up.

As far as noise cancelling, I'm currently using Bose "QuietComfort 3 Acoustic Noise Cancelling Headphones"; they're an on-ear model and I generally prefer around-the-ear, but since I've already got the earplugs there's probably not much reduction lost there.  The headphones were a gift, I didn't put much stock in the idea that the oppositional wave thing would work; don't two pressure waves pass through one another and emerge more or less the same on the other side?  I guess not

[Hearteater]

Earmuffs used on firing ranges aren't what you are looking for: they block only really loud sounds like gunfire (although they are generally have a sensitivity setting).  But when on a firing range normal talking doesn't trigger the noise-blocking at all.  Which is basically the point of them.  If you don't mind modifying your workroom, you could add some soundproofing to the inner walls.

[keith.lamothe]

Earmuffs used on firing ranges aren't what you are looking for: they block only really loud sounds like gunfire (although they are generally have a sensitivity setting).  But when on a firing range normal talking doesn't trigger the noise-blocking at all.  Which is basically the point of them.

Right, the ones I was looking at had a much better -db on higher frequencies than that stuff.  But yea.

If you don't mind modifying your workroom, you could add some soundproofing to the inner walls.

We've been looking at options there; we can't do anything inside the walls (renting the house) and we could try the panels that are applied superficially but I'm trying to find if less involved (and less expensive) means will be sufficient.  And our walls are actually pretty good at insulating sound.  We might wind up soundproofing the door, though; looking at 500-600 dollars of stuff for that as far as I can tell (taking http://www.soundproofcow.com/door-soundproofing/door-soundproofing-kit.html as an example; does that look normal for that kind of thing?).

Right now we're working on hanging a curtain in the hallway that leads to the office (it's at one end of the house) and maybe putting some throw rugs or other padding on the hardwood floors in that part of the house.

[eRe4s3r]

If you want silence in your room the door and door-frames are probably the first thing to approach. Most doors nowadays are not better than a 1cm thick plastic plane - worse, they have hollow cores and so sound is not only transmitted but enhanced.

Theres 2 things about doors that can be improved without buying a new door.
Thats the rubber seals between frame (or floor) and door
And the door itself (there are sound-dampening mats that could be "cut to form" to work with your doors, but they'd need to be applied on both sides and that may be a lot of work.

Then theres carpets and lots of "stuff" at the walls, anything that breaks and absorbs the sound waves.

Generally, buy carpet for the room you are in, and the room your children are noisy in, then if thats not enough, think about buying a non-wooden door with high material density, and lastly try to make the door seals tighter..

In the end, all of that is stuff you need to ask a specialist for, the door and door frame is the prime reason you hear noise (unless you hear it from outside, then its the window and window frame)

[keith.lamothe]

In the end, all of that is stuff you need to ask a specialist for, the door and door frame is the prime reason you hear noise

Thanks for the info on the door being the weakspot.  That's been my guess too.

When you mention specialists, do you mean paying someone to get the stuff and install it, or just to look at the door and make a recommendation?  Are the DIY kits like http://www.soundproofcow.com/door-soundproofing/door-soundproofing-kit.html not likely to work out (or not be reasonably DIY)?  Though I guess that particular kit is for metal doors, not the standard wood-hollow-core internal doors like the one I'm dealing with.

[eRe4s3r]

My mentioning specialists is because sealing interior doors can quickly become an issue, as in, air-tight = pressure = air circulation issues (depends how well the seals connect) and how tight the windows are.

People easily forget that this can become an issue ^^

Also, the door frames you linked to in that DIY package, they would be fine, but that additional mat would make 0 difference if the door is a general interior wooden/hollow door construction. Maybe if you'd take the challenge and cover the WHOLE door with the mat (optimally a perfect fit with the frame seals) but it'd require very exact cutting and measuring.. and keyholes.. well they are holes in your door so those are naturally very bad for the sound dampening

Ear-plugs are definitely the easier choice..

Generally speaking.. the more material between you and the noise and the tighter the sealing, the less you hear of it.. which is why ear plugs are so easy, they seal at your ear which is an easy place to seal tightly.

Sealing a whole door tightly is vastly more bothersome, worse still, with doors you often have not very much material at all, and as such it dampens very little... even if it were tightly sealed

[x4000]

What about something simple, like white noise? We use that in my son's room, and he can't hear hardly anything when just a regular vornado fan is running in there. It's eerie. Then of course you have the white noise of the fan, which is annoying, but it might be interesting to see howthat combines with your earplugs, which are great at blocking noise of that sort I presume.

It might be totally unworkable, but it's also pretty darn cheap (possibly free, if you already have a loud fan) to try.

The other thing that occurs to me is cheap DIY door soundproofing. We hang blackout curtains on my son's windows so that he can nap, but we made the discovery that it also really blocks incoming sound from outside. Not completely, but it really helps a surprising bit.

This, again, is free: if you have a heavy quilt or blanket, you could experiment with it on both sides of the door and see if anything helps.

Maybe you already tried things like that, but it seems to me that you aren't in need of perfect sound damping: you need to reduce the incoming noise from your primary vectors of incoming sound, and then your existing solution will probably take care of whatever slips through. But instead of stacking more earmuffs on or whatever, you're blocking something better, aka general room noise in one fashion or another.

Another thig you might look into is a standalone active noise cancellation technology. Not earphones; this is something that sits in your room, plugged into the wall. My dad has been around those before, years back, and said they were amazing. They could basicLly eat all the conversation from someone right in front of you. But these were big, commercial, presumably very expensive devices. It was also a decade ago. So I have no idea what is on the market for that sort of thing, if it works, or what it costs. But the ethnology itself is very real and not bunk; even if there is likely a lot of snakewater oil being sold under that market name. I have no idea if that's cost feasible, and it mitt be overkill, but it would also be something you could bring with you to future houses or on trips, etc.

May not be helpful at all, but I know very little about this. I dabbled with noise cancellation headphones, but the active ones give me a headache despite working kind of well. So I just got used to playing music through my normal speakers, and tune out the other noise. That doesn't work for everyone, though, and there are definitely times when it doesnt work for me either.

[Otagan]

I saw a thread on another forum recently that discussed noice cancellation for the purpose of aiding sleep, but I'd assume this is roughly comparable.  They recommended a device like the one Chris described above for standalone active noise cancellation and recommended this particular one:

http://www.amazon.com/Marpac-Sound-Screen-Sleep-Conditioner/dp/B003DQCHY0

While I can't vouch for its effectiveness, multiple people did believe it was helpful at negating sound from elsewhere in the house and creating a quiet environment.  While designed to aid sleep, for your purposes I think it would stand a chance of being effective.  The price is also rather reasonable, all told.

EDIT: Looks like this one has a larger pool of reviews and offers a little more functionality.

http://www.amazon.com/Marpac-980A-Screen-Conditioner-Generator/dp/B000MPH0PG

[x4000]

Wow, that's definitely in the price range where it's worth a shot on recommendations alone.  I mean, my noise cancelling earphones cost twice that much, and they were considered relatively "cheap" ones.

[eRe4s3r]

This isn't noise canceling though, these cylinders have been around since the 60'ies. They raise your noise-sensitivity dead-zone by flooding the air with a certain kind of white noise. Works great, though its not exactly what you want when you mean "silence" ;p

that said, i use a much cheaper method (the fan on my NAS) and it works just as well, but against really loud noise it doesn't really help unless the door absorbs large potions of it. Also while your sensitivity is lowered when a noise does get your attention its twice as distracting imo..

As for me, i can't work in a room with an analog clock, like at ALL. So in my house theres no clocks that are mechanical. That noise is so impossible to "unhear" that once i have locked up to even 1 clock i hear them all.

What we all really need, is selective hearing augmentations. Where you can filter out any particular noise digitally, that'd be awesome...

[x4000]

Oh yeah, actually that cylinder isn't what I thought it was -- you're right, that's just a white noise machine.  What I was talking about was active noise cancelling -- like the headphones -- that's a larger standalone unit.  They emit sound waves that are in opposition to the incoming sound waves in order to cancel them out.  They're much more expensive.

Analog clocks drive me a bit batty, too.

[keith.lamothe]

Thanks for the additional suggestions and info

We're trying a variety of relatively simple improvements for now and the situation has gotten better.  If necessary we can probably convince the landlord to let us hang a different door, as we're pretty good friends with her.

And yea, if a clock ticks, the clock dies.  Well, not if it's someone else's house.  Usually.

[Otagan]

Works great, though its not exactly what you want when you mean "silence" ;p

The description seemed to suggest otherwise, but that'll teach me to not actually read the details before posting.  Oh well.