my youngest is 18months and not yet talking but has started squealing at the top of his lungs. A high pitched,possibly ultrasonic squeal that i wish only dogs could hear. This then sets of ds1 who is three and he joins in for a squealing competition so at least four times an hour the two of them are screeching at the top of their lungs. How do i stop this?am i fighting a losing battle its just i fear i may lose my sanity/ability to hear some time soon. Any baby whisperer tricks out there.