Our 15 yo son is always listening from his room and it is surely not good for him. I managed to do "a talk" with him when he was around 13, explaining that "mum has a strange brain with ups and downs, and you should not take it all into your heart". He is now used to it and also knows how to handle her and not put out fire with gasoline.
Yes, the walls do have ears. While there is little you have been able to do to help your spouse, the children are a different matter. You can do what you can to present a good example to your children. They're impressionable and your example, even in these bad situations, can make a difference in their futures. For one thing, you can help them to avoid choosing their own adult relationships in healthy ways so it isn't an unbalanced and dysfunctional controller vs appeaser.
In other words, our homes - as much as we wish it wasn't the case - were/are dysfunctional to a greater or lesser extent. So our children don't know what normal family life is truly like. So we have to make conscious effort to ensure that they don't think the life they've lived at home is their unavoidable future. Make sure you share positive experiences and associations with them.
Another idea is to periodically have
regular heart-to-heart conversations with your son. Don't assume he's okay if he doesn't speak up or approach you. There will even be times he won't even know what to ask. Thoughtful parenting includes being proactive about it.
