Strange noise after baby seat install

[svniu]

So about a month ago I installed a baby seat. Shortly after, not sure if it's a coincidence, but started hearing a shhhhhhh sound, kind of like air. It usually occurs on bumps coming from passenger rear (right where baby seat is). Very strange noise.
So today I took the seat out completely and noise is gone.

Very strange.

[Courage]

Airmatic version of the baby seat?

[Whosdis]

Maybe road noise is being transmitted through the baby seat due to being solidly anchored to the body?

[mlfun]

How big is the baby ?

[Mike's ML]

Try changing your kid's diet.
Mike