Dodge ram 3500 clown whistle

Sounds like you have a turbo with a bad bearing.
pull of the turbo and rotate it by hand to see if it is hanging up.
Most turbos start to make a different noise when they start to go.
Sometimes dirt can bypass the air filter if is not changed on a regular basis and can cause the turbo to fail or become dirty enough to cause it to spin slower, (the dirt prevents the exhaust to spin the turbo at the right speed and the air passing the fins can whistle), it will cause bearing failure after a while. Also if you have too much soot in your exhaust from too much oil, the exhaust side of the turbo can become too dirty to operate properly