Turn on the vacuum cleaner.

Naturally you should check a few things first. Usually a baby cries to tell you something. The messages are few, but indistinguishable, - at least to new parents. They kinda go like this:

1. Bring food
2. Change diper
3. Blurp underway
4. Hold me
5. Too hot
6. Too cold
7. No, I don't want to sleep

Sometimes the baby won't stop crying - not even  after checking all seven possibilities. Then try the cleaner. It works like magic. The baby stops crying almost instantly. Hmm, - it is kinda strange, but the theory goes, that the sound reminds the baby of the time inside the mother with all sorts of noises from a diversity of streaming liquids.

However, is pretty annoying to have the vacuum cleaner running at alle times plus it heats up the room and it smells strange. Google for "white noise baby", and you will find hundreds of stores that will sell you CDs with white noise. Get one. 

Or try one of these buttons... they kinda have the same effect.

Nature soundscapes

Artificial soundscapes

Yes, turn it up. It has to be as loud as the vacuum machine, but do not use earphones as it might hurt or damage your babys ears.