My opinion is that they can learn the sounds of a language by listening, so I would expect your child to pick up some vocabulary and speak it without an accent. HOWEVER that does not mean that they will speak the
language by listening to a cd. Language needs people and interaction to be learnt.
Look at it as like learning music - a child might learn the musical notes and their names from listening to a cd, but they would be unable to play the piano. They could maybe pick out a bit of a tune, but to play piano you need to learn piano and not just the notes a piano can make.
I use language cds with my son all the time - he listens to Russian and Chinese on cd and LR (LR especially helps with vocabulary as there is the associated picture). I use audio recordings of language mostly to help with acquiring a near-native accent and a more intuitive understanding of how the language sounds. I do not use them exclusively and I would not expect my son to learn much using them alone.
An example of how much more effective a teacher is - for the week that my son's father visited and spoke exclusively Russian to him (rather than my 1-2 hours of odd conversations and reading throughout the day) the rate at which he was picking up Russian was equal (maybe even greater than) the rate at which he was picking up English, which is our primary language. He learnt (and began using what he knew) more in 24-hours of interaction with a native speaker than in several months without.
I wouldn't say that cds are useless and a waste of money, but playing a set of cds with 1000 words will do no more than teach those 1000 words as separate sound-bytes. You would be better spending your money on some good quality childrens audio books and dvds in the target language (for general immersion and native accent) and something like Little Reader, Little Pim or Wink to Learn for meaningful vocabulary building. You would probably have some money over for a couple of hours with a teacher, too!
Hope this helps - if you know what language you want your baby to learn, I might be able to give more specific advice
Digg
