I get easily woken up by loud neighbors, babies crying and general noise if it's too much to handle. Beijing's not exactly the quietest city out there, so I was wondering where I could by a sound machine, something that outputs white noise when you plug it in.

I asked several stores (supermarkets, electronics stores) and none of them carry something like it. This is the exact model I'd like but unfortunately it doesn't work in China as the voltage is wrong:

http://www.amazon.com/Marpac-Sleepmate-580A-Conditioner-Single/dp/B000LQ...

I found something that would work on Taobao, but I would rather not buy from there as 1) I have no way to test if it works or not/the noise is okay and 2) it's pretty expensive:

http://item.taobao.com/item.htm?id=12294615914

The name of this type of item is 睡眠机 or 催眠器 according to some Chinese friends...but they too don't know where I can get something like this.

Where can I get this in Beijing preferably? Online is okay too if it's not too expensive.