I live 200 feet from a 6 lane highway, and the noise is rather annoying to say the least.
I would like to reduce the noise coming into my 58"x 70" bedroom window by at least 50%, as I think the noise is causing stress and tension.
Unfortunately, moving is not an option.
I am looking to do so for a budget no more that $100 for materials.
Is it doable?
Road noise is often underestimated as a cause of tension and stress, so you are on the right track.
There are of course windows with better noise attenuation available but this could be outside your budget.
Adrenaline and another stress hormone called cortisol bring on physiological changes, including a spike in heart rate and blood pressure. Your body reacts so fast; you often can’t tell these changes happened. Chronic exposure to noise keeps this stress response activated continuously. Eventually, it starts to wear the body down, causing mental and physical health problems.
A simple solutions involves placing a combination of heavy potted shrubs and heavy curtains inside and/or outside at the window, plus heavy carpeting inside.
Image: Sound Proof Curtains, Amazon
Additionally you can reduce the stressful aspect of the noise by masking it with a table top fountain inside or outside near the window.
This is generally a low cost and low effort measure that can be quite effective.
There are real water options of course, but also electronic sound machines. These do not reduce the noise itself but work by masking the noise (noise can make other noise less perceptible) and they distract the brain with more soothing and pleasant sounds, thus reducing stress.
Personally I find a real fountain far more effective than an electronic one, due to the quality of the sound from real splashing and how it is spread around in the room (the sound spectrum and radiation pattern).
Image: Cascading-Bowl-Brick-LED-Fountain, Amazon
For heavier attenuation you can build a noise shield, which can be applied in addition to the above options.
This is a noise attenuating insert, box or panel that you place outside or inside, against the window, depending on space, weather and other aesthetic considerations.
If it's a box or a wooden panel it may contain a glazed window opening (glass or plexiglass) to let light pass through. The size of such an opening determines how much noise still gets through. You can make it removable so that it is only mounted when needed.
There are also all-glazed noise attenuating "inserts" which you install snugly against the existing window. But attenuation is only 50 5o 70%, which really is not enough (see below)
A noise attenuating box or panel is made of heavy material, such as a few layers of plywood or particle board, and noise absorbing material such as foam or fabric placed in the box or attached to the panel on the face that faces the window. This panel or box must fit snugly against the window to seal off the noise. You can lean it, hang it, lock/arrest it etc...
You can build your own with thick plexiglass (the thicker the better) that is cut to size at a shop, and a vinyl edge guard or foam bumper around the pane's edge to form good acoustic seal with the window.
Image: https://www.bobvila.com/articles/soundproofing-windows/
Cutting noise or sound reduction by half actually doesn't do much; "half" is a perceptible difference but it's far from making a difference in terms of stress. You need more like an attenuation of 1/10 to 1/100, preferably 1/1000.
What factor is sensible is not only a matter of the desired attenuation, but also a matter of what can be accomplished despite the noise transference of other surfaces, such as the walls and doors. If walls and doors a poorly insulated, say at 1/10 attenuation, then bringing the window to 1/10 is a great improvement, but going beyond to 1/100 will do little more incrementally.
Studio-style acoustic foam panels can be used to attenuate sound, but beware their function is to limit reflections. Hang them on a wall and you'll have less of an "empty hall way" sound in your room. This certainly can help, in the same way that faux-curtains and carpeting can help. But they are actually quite poor at attenuating sound transference, i.e. stopping sound from going through them. Moreover, the low cost ones are made of a light foam pad, and although better than nothing, they are not at all to be compared to studio grade panels. They can be recommended for a pod-cast box in the corner of an office or bedroom, to improve recording quality, but not really for sound proofing.
Consider testing your idea first - try wearing some cheap foam earplugs and see how that helps your sleep.
This is just a short-term way of checking up whether the noise reduction will help before committing to spending much money at all.
You may already have some. Cotton wool in the ears will not work as well, and external protection like earmuffs/ear-defenders are too bulky to sleep in.
You should have an idea within one night if this will help. Good luck !
Just a note: The window may not be the only way noise is coming into your house. Having blown-in insulation added to my (previously minimally-insulated or uninsulated) walls significantly reduced noise from outside.
Do you care about aesthetics? Buy some sound baffling foam. You can get 50 sq. feet for about $40.
Leave it black or spray paint the back of it white and fill up that window; double or triple layer it. Heck, cover your walls with a layer and enjoy even more silence.
In dealing with sound they are multiple approaches.
One is a reflection and the other one is absorption.
The reflection is achieved with a hard surfaces materials while the absorption is achieved with heavy soft and thick materials.
Example used on highways:
Assuming you don't use the bedroom during the day you would like the window to maintain its function of letting the light and sun through it.
For the reflection you will use acrylic plastic sheet probably 1/4 inch thick, and mount it on the outside.
For the absorption during the night you will mount shutters on the outside and heavy curtains on the inside
You could go for a somewhat thick plastic sheet (eg acryllic or plexiglass) and place that on the outside of your window.
If you make the sheet a little wider than your window and use standoffs in order to make it about 10cm/4" away from the window you might get a fairly good bang/buck. Just dont make the standoffs of something to hard like metal, than it would transfer it anyways.
This is something which you can test before committing, if you can jerryrig a temporary budget solution, you can see wether it aproaches what you want.
Glass would be better because of its higher mass, it dampens more, but that would also complicate placement (glass might be cheaper though!).
Edit: If you add a simple wooden framing around in it similar colours, it might appear more as a regular window.
Rough but cheap and probably reasonably effective:
