noisy double glazing only 4 years old

[helpusplease]

Hi. we have just moved to a property which is near a road.The property had new double glazed windows and doors 4 years ago so I don't really want to replace. The road is to the rear of the property (where the bedrooms are) and they have vents on these windows. I have shut all the vents but it still sounds like we are outside when the lorries start at 5.30am in the morning. Is there any way of making the windows more sound proof. I expect not but would appreciate any help.
Thanks
Meg

 

[big-all]

shut the window with a sheet off paper between rubber and window and see how easily it moves

you can get replacement rubber off varying sizes to fill bigger gaps from your local d/g place

 

[crank39]

It can be as simple as worn rubbers or ones that have flattened, it can also come through the trims used to make good, i see in a lot around bay windows, fitters hardly ever foam the voids before trimming, if your windows are trimmed up exsesively then its the first place to look, other than that it could be trickle vents

 

[orchard222]

When you say vent's do you mean trickle vents in the head of the frame/sash ?. If so the only was of sealing them up would be to remove the internal vent and fill the elongated hole with silicone, once done smooth over and replace the vent to cover the silicone. Once dry the vent will be rendered useless for it's purpose, but it would of cut the sound down quite a bit. I know i have done it to my bedroom window and worked a treat. Hope this helps.