He did sit in the congregation while a screaming baby, me, was in his ear. Since you didn't know him, please don't assign your own ideas to what he believed and knew. He was a faithful servant in the church for over 50 years. His belief was that children should be in the congregation because it accomplished several things. It allowed them to see from an early age how a service was conducted. It required parents to actually be parents during a service. Just listen to a small child that has actually sat in the service and you'll find out quickly just how much the child is hearing and taking in. Yes, they are often just parroting what their parents do, but is that not how we learn every behavior we have? And I don't know if you know it or not, but hearing a three-year-old say amen when a man is preaching is extremely uplifting.
He strongly disliked the idea of nurseries because, as he told me, it takes people away from the service. Some churches he knew of (and I only knew in passing) had such a developed nursery system that they didn't allow children into the congregation to hear preaching until the child was over 13 years old. That, in my opinion as well as his, is just wrong.
No, the volume at which a man preaches is not what makes it preaching. I would be a bit concerned if you have such a soft-spoken preacher that the littlest noise in the congregation could completely distract you from hearing him, though.