What happens next?

How to get a dog to stop whining
Keep track of when they whine.
Is there a particular catalyst for their whining? Which situations cause them to act up the most? Take notes about the context for each time you hear them whining. More often than not, there'll be a pattern that you can recognize if you're alert to it.
Once you identify the patterns and contexts for their whining, it will help you create a strategy for addressing it. Figure out if it's related to a medical condition.