Have I harmed my baby’s brain?

Hi everyone, I am seeking advise/wisdom from other Catholic parents. My husband and I have lately been watching TV together at night for a few hours. During that time, our 4 month old baby is either breastfeeding, napping, or awake. When he's awake, I try to position him away from the screen, although he sometimes will have a glimpse of it. I'd say that he sees a screen for a maximum of 15 minutes a day. However, I've just learned that even having a TV on as background noise is harmful as it impedes baby's language learning. My husband is not too concerned, as baby has plenty of contact with us, gets held constantly, gets read and sung to, etc. I still feel really guilty that we've been playing the TV in the background for hours, as I believe in limiting screen time for children as much as possible. Would really like to hear about your experience parenting in this area, thank you.