One of my big reasons for going ICF was noise reduction (I am a light sleeper). We have drywall up over 6" concrete + 3" Foam on Ext, 1.5" interior, and I did t think that much window. Windows are foamed in place. Triple pane, argon filled, with grilles between the glass. Windows are 11% of entire building envelope, tho only one is below grade. I could never hear them in my parents old 1980s home! Why can I hear the birds whistle an the geese honk?

What kind of roof do you have???

Exactly, what kind of roof, Attic ventilation and insulation? Do the bathroom vents go up thru the roof or out thru the walls... How about whole house/HRV vent locations?

Wood truss with RC60 worth of blown in fibreglass insulation

fiberglass blown-in Insulation traps air to insulate, and by design is low mass when properly expanded. Air conducts sound waves... Without some mass to absorb/deaden it, that is probably where the sound is coming from. I am doing the framing on the same type roof over ICF at this moment. I was planning a layer of Rockwool under the blown-in insulation for that very reason. It could also be that the sound is entering thru a un-dampened ventilator duct, but this would probably be apparent that the noise was louder in the room with the duct...

At this point, you might try diluting out the noise. For example, a room air purifier.

My understanding is that better windows for sound have large (like 4") air gaps, dissimilar glass and no grills. All accounted for in the STC rating.

What's the exact model of your windows?

I am a light sleeper as well and one of the main reasons for going the ICF route is the outside noise. I would go nuts to have finished the construction and find out that noise is sill coming in.

The grilles between the glass may be the issue here.

To find out whether the windows are the culprit you could try doing a little experiment: take a piece of drywall the size of your window opening and glue it to a piece of OSB that is slightly larger than your window opening by 2-3 inches on each side. Then screw the osb board to the wall so the drywall fits right in the window opening. Obviously you may want to seal as much as possible with some foam rods. Basically create a window cover. With the osb board and the drywall there should be significant noise attenuation coming through that window. If you can still hear the birds, then the noise is probably coming from somewhere - like the other have said - through the roof.

Interesting thoughts, all

The windows are a local manufacturer, triple pane, argon filled, with the GBG, that pass Canadian Cold-weather standards (I forget the exact code)
The windows have a small bead of foam around them, but otherwise no trims/finishing around them.
The osb idea sounds neat, my only concern would be ruining my finished and painted drywall :\ Would any chance heavy curtains have a similar effect? Cause I could use a tension rod to temporarily hang those...

The plumbing stacks do come out the roof.
The bird noise is surprising as the bird is over a 100' away, and the sound is crystal clear and loud!

Any suggestions for after-the-fact sound deadening if it is the roof?

I have no idea. Birds are LOUD this time of year......matting season......  

Posted By robinnc on 12 Apr 2017 05:49 AM
I have no idea. Birds are LOUD this time of year......matting season......  

I used to live in Moses Lake WA which is a stopover point for geese migrations. Sometimes if they got to making noise as a group, it sounded like a rock concert just down the road. VERY loud!

Posted By Geergirl on 12 Apr 2017 01:24 AM
The windows have a small bead of foam around them, but otherwise no trims/finishing around them.

The bird noise is surprising as the bird is over a 100' away, and the sound is crystal clear and loud!

"Crystal clear and loud" Hmmm Sound passing thru any medium other than air should alter it's characteristics to some extent. R60 and ceiling drywall should at least muffle it a little. The fact that you note it as crystal clear indicates to me that the sound is passing thru some opening in your envelope.

Have you done a blower door test? If so, what were the results? If not, that in conjunction with a smoke machine outside your window(and door) frames could show any leakage around them pretty easily. It also could be something as silly as a missing window seal. the window is closed, but the missing seal allows the sound to pass. You could also have an unsealed ceiling penetration...

Your plumbing vent stacks should all be connected to plumbing, and if all the P traps are full of water should not be able to conduct any noise. Back to an un-dampened ventilator. Bathroom vent? Dryer vent? Kitchen vent? HRV?

The windows have a small bead of foam around them, but otherwise no trims/finishing around them.

If it's still possible, I'd add some good quality tape (like 3M 8067). Much better at air sealing than canned spray foam.

we haven't done a blower door test as the house isn't totally finished. In the next week or so, when it finally gets above freezing, the builder wil be flashing around the windows, stucco, etc.

Jonr- not sure I understand where you suggest we tape - on the Ext wall, or the interior?

ptraps and plumbing stacks - we only have 1 sink installed in the mudroom, so the rest of the plumbing lines are just capped at this point

OK, I didn't realize you were not in a complete state of finish. That makes the hole theory a whole lot more plausable...

not sure I understand where you suggest we tape - on the Ext wall, or the interior?

Either one - wherever wood might shrink/warp/move and open up a crack. Easy now, hard once everything is sealed up.

+1, also caulk might seal out noise where you cannot tape easilly.

I'm going to suggest a few things. First, being unfinished you likely have sound paths that will be closed off later. Argon is more dense than air so I think it is transmitting sound from pane of glass to the next. The only way to have zero sound transmission from one pane to the next is to have a vacuum between them which is not practical. As has been said, I think the grills act as transmitters, especially if they touch panes on both sides. Another factor may be the frequency of the sound. I have an ICF house with Anderson 400 casement windows. Train horn sounds from about 1/4 mile away come through clearly, but very few other sounds do. The goose honking may well be of a similar frequency pattern and be the resonant frequency of the panes.

Geergirl - your house doesn't sound that different from ours. A two storey with walkout basement, ICF to the trusses, triple glazed SDL with low-e argon. Lots of big windows. Roof is wood trusses c/w OSB sheathing and metal cladding. R60 cellulose insulation.
While it is possible to hear geese honk, it is very muffled unless you open a window.
Starting place would be to determine if this is a whole house issue or just one or two rooms.
If one or two rooms, trace sound back to source. Maybe a heating duct or a particular place in the outside wall. If it seems like it is coming through the outside wall, it may be that the concrete mix wasn't quite right and it bridged on the rebar and webs leaving a hollow in the pour.
If it is whole house, than almost for sure it would be the ceiling roof stack up. That being the case the first thing I would do is blow three or four inches of cellulose over the fiberglass.
Sound travels in straight lines so you should be able to find the source but you definitely should not be able to hear the geese like they are in the room with you.