There are so many benchmarks and milestones to look for when you have a baby. There’s holding their head up, smiling, sitting without support, crawling, and walking, among many others. One of the biggest milestones parents look forward to is babbling and talking. Hearing affects those two milestones though, and you may be wondering how to tell if your baby can hear, especially if they aren’t reacting to sounds as an infant, or beginning to babble at about 4 months old.