I am staying in fifth floor facing road, near LRT/ bus stop.

I noticed some buses stopped with a very high pitch, screeching noise which is

very annoying, coupled with some motorbikes picking up speed......

Currently my study room has four panes of sliding window (total size is 3m by 1m, LxH)

I have thought of double glazing window, and tried to call some shops.

One sales rep suggested uPVC.

Anyone had experience in installing windows that can shield off noise? Price?

no, but to shield off noise many methods:

1) thicker glass (dunno if allow)

2) the rim of the frame has a row of "hairy".. dunno what u call that. Basically when u shut the window, the hairy thing will prevent u from straight slambing metal to metal.

Thanks for the suggestions.

I think sliding window is quite difficult to shield off noise as the gap is quite visible...

i have seen the "hairy" thingy. I believe they are used under a door.

How about some Roman Blinds?

oppsss sorry, din't read properly, mine was a casement window with the "hairy" strip.

perhaps u can call up a window maker to ask for advice. They being the expert probably can offer u some solutions.