I work in a pretty noisy environment, lots of noise near me like the TV and people yelling and talking in really loud voices. It makes it really hard to concentrate and since I can't really move my PC to another part of the house I was thinking of getting a decent pair of noise-canceling headphones. I've never owned or used a pair before so I wanted to ask, do they block outside noise completely? As in, I'll hear nothing but silence as long as I'm wearing them?
Like the other two posters said, the Noise Canceling headphones only work on constant noise. When I got mine, I thought they were defective, because I could still hear the TV. It wasn't until I took them off that I realized that they completely blocked the sound of the clothes dryer that was running. I love them on a plane as they block out 90% of the engine hum. If you want to block out variable sounds like people talking, TV's etc, you need to look at a headphone that goes into the ear, and functions like an earplug, while being a earphone as well. The cheap headphones like SkullCandy ($9 US) with the silicon seals do a better job of blocking voices than my Sony Noise Canceling over the ear headphones($50-$60 US).
To block all noise you want earplugs or ear-protectors. Any safety supply store will have them. You can probably pick them up at your local home store or lumberyard too. There are lots of kinds. Personally I prefer the compressible foam ones that re-expand to match the shape of your ears. Some people find them uncomfortable and prefer over the ear hearing protectors instead.
Check out the dB reduction rating. There are differences between brands.
The main advantages of earplugs are they work great and they are cheap. The main disadvantage is you look like a dweeb wearing them in your living room. Embrace your dweebdom and get your work done.
I used to wear Sennheiser PXC 250 ( http://reviews.cnet.com/headphones/sennheiser-pxc-250/4505-7877_7-21258924.html) noise canceling headphones for flights (am Elite on Air Canada, with about 60 flights a year). Switch about a year ago to Shure SE 115 noise isolation ear phones ( http://store.shure.com/store/shure/en_US/pd/productID.121026300).
The difference is amazing. With the Sennheisser's I could still hear people talk, and some of what was going on around me. With the Shure's, I am deaf to the world. As an added benefit, the Shure's don't require a battery, are smaller and more confortable.
I tried $400 and $200 Sony noise-canceling headphones at Best Buy. They were hooked up to rock tracks, and you pressed a button to broadcast the sound of a jet engine from an external speaker. They didn't kill the jet sound, only lowered it by maybe half. They were the style that covers the ears with a cushioned rim - which would've blocked out part of the external sound anyway, without the noise-canceling. I also tried 2 other sets with the jet sound playing, different makes, and they were also ineffective. Plus, I didn't like the tone of any of them. They tended to muddy up the sound with too much bass. There were many other models but you weren't allowed to listen to them!
So I don't recommend noise-canceling headphones, or Best Buy. I went to a pro music store (Long & McQuade in Toronto) and got a pair of Shure headphones for $60. Not noise-canceling, but covered the ears comfortably. So they lowered ambient noise, and most importantly sounded good,