Don't waste your time, look for NoiseBlock link attached: http://www.noisestopsystems.sg/soundproofing_windows_singapore.php
I moved back to sg this year and was shock how noisy my condo was. So like anyone i search the www found a very nice looking website had the 'acoustic consultant' come over give me a quote and it was a bit pricey but i signed up anyhow.
After install the result was only a little better, the company did some report or whatever and said that it was soundproof and try to brush me off, i'm no engineer so no idea what this report was saying just that it was pass.
I was very unhappy with the results and did not pay the balance payment and left it as that.
Then after a few months I couldn't take it any longer so I asked some friends and other coworkers any ideas, my boss recommend me to call NYTC noise stop system and look for nelson.
I phoned up spoke to some reception girl who pass me a number and ask me to call. (NELSON)
I phoned a few times left number and did not get through. I felt at the time the service sucked and was going to give up and try another company.
Eventually Nelson called me back, after speaking to nelson you don't need to speak to anyone else, no joke. You may need to sms or wait for him to call you back which i admit is lacking on customer service, but the guy is a walking encyclopedia for a-z of soundproof. I went over to his office at kaki bukit and he explained to me in detail everything to do with windows.
I have had such a bad experience and reading all this I hope to save others time and money, I also feel that I owe it to nelson to spread the word.
Double glazing is nothing to do with soundproofing its to do with thermal, 2 pcs of glass one outside, one inside to buffer the hot and cold air.
Next the glass must be sound rated glass, not lami, not low e or any other glass, so even you got a window with 2 layer, 3 layer if the glass is wrong no result.
Inside the frame not like normal window, got lots of funny things going on, difficult to explain, there was a lot of different materials inside.
Nelson told me that their company give a guarantee of performance, which no one else could give.
Anyway after installing the windows and door, the noise was not just cut a little bit, it was totally cut. and I mean NO Noise!
So don't do what I did: think before you buy, flashy website, salesmen with honey talking only want to tell you what you want to hear then you buy and regret.
Now I know why its hard to get hold of Nelson, but for me I am glad that I did.
Hope my story is helpful, sorry for the information overload too much coffee LOL