6 month old failing hearing test due to fluid in ears. How concerned should we be for his development?

Our 6 month old has failed three hearing tests. They said he has fluid in his ears which could be causing the fail. We have been concerned as he is a very quiet baby. He does not babble or talk to us or laugh without being tickled. He will turn in the direction of very loud noise, but seems like he can’t hear any low frequency sounds. He has had one ear infection which was treated with antibiotics. We didn’t even know he had an ear infection, it was only caught when we went to the dr for cold symptoms. He never indicated his ears hurt. We have another appointment with the audiologist in a month and they said it is too early to tell if he is hard of hearing and that they won’t do any intervention before he is one anyway.

As we notice he does not babble, what are the long term impacts on verbal development? If his ears stay status quo and intervention only happens at a year is he going to be at a disadvantage developmentally? Can this cause lifelong impairments?

Is there anything we can do to help him at home? Any tips/tricks/advice welcome.