she has found her voice.

it can get annoying and very loud but learn to enjoy it cos she certainly does. if she had a hearing prob she wouldnt be making sounds, she is listening to wat she hears and is tryin to copy.

Like all the others said, it sounds like she's just trying out those vocal chords - nothing to worry about! Good luck.

Your 4 month old is exploring her voice!  That's all it is.  She will squeal, she will laugh, she will make weird noises all for her own amusement. and yours.

Your daughter certainly doesn't have hearing problem.  if she did, I would expect her to not be going through this.  No, your daughter's hearing is just fine.

Being loud is part of exploring her world.  She is finding who she is and where she fits into things.  It is also part of learning cause and effect- she squeals etc and gets a reaction from you, which encourages her to do it again.

It is a fun time to be with your daughter as she is learning new things very very quickly now.  Having 5 kids (my youngest 4 months old) I know that it is all normal as with my first, I had a great child health nurse who explained much of the stages to me (she was married to a child psychologist too!).

I think there's nothing to be worried about, all babies do the same, my baby was doing the same when she was in your baby's age. but if you still worried and concered about it then go to your Doctor and talk to him about it ...

my personal reason is that all kids shout/scream/squeal at some stage.  My son used to do a really high piched scream at this age, some times he still does it.   I think your 4mth old has just found his voice and likes the sound of it.

If you are really concerned then talk to your doctor or health nurse.