Can we soundproof our flat to block out the noise of our neighbour's children?

Every week a Guardian Money reader submits a question, and it's up to you to help him or her out – a selection of the best answers will appear in next Saturday's paper. This week's question: We live in a top floor flat. The toddler downstairs makes quite a racket, and one of the older children is learning the drums. We have wooden floorboards – what are the options and costs for soundproofing? How do people deal with noise? Should we break in and steal the drum kit? What are your thoughts?