Your Baby Can Hear Sounds Outside The Womb At This Stage Of Pregnancy

You may have seen it in the movies: parents singing in off-note keys to their unborn children or crooning sweet nothings to enlarged bellies. Can babies really hear what you're saying to them from the outside? 

You'd be surprised to find that — just as babies develop food preferences while still in the womb – their ears develop to such an extent that they can actually start hearing voices and other sounds from outside the womb. When does this happen? At approximately 22 to 24 weeks into the pregnancy. Looking at the various stages of development of your baby's ears could give you an indication of when you should be sitting down with a book and reading bedtime stories to your unborn child. 

At just two months into the pregnancy, the tiny embryo will start developing ears, per Medical News Today. This process continues as the embryo turns into a fetus by the end of the second month. Once your baby reaches nine weeks, you may even start to see small dents where your infant's ears will be, according to Verywell Family. At 16 weeks, the ears will have gathered more form. The baby's ears will be developed enough to pick up sounds from the inside. This would include the beating of your heart, blood traveling through the umbilical cord, and various stomach and lung-related noises, etc. 

At 24 weeks, you can start talking to your baby

At 24 weeks, your little one will start hearing your voice if you speak to them. In fact, according to the medical director of the MemorialCare Center for Women at Long Beach Memorial Medical Center and Miller Children's Hospital, Michael P. Nageotte (via The Bump), "A loud noise can cause the baby to suddenly move, and that response becomes much more consistent as the pregnancy progresses." This may be one of the reasons why your baby moves a lot in the womb when you sing to them.

The most crucial time for hearing development is when your baby is between 5 to 6 months of age, per a 2008 study. By the time the 6-month juncture comes along, babies react to stimuli by turning their heads toward the direction the sound is coming from. 

If you want to hear what your child might be hearing from inside the womb, you can try putting your hand over your mouth and saying a bunch of words, according to clinical neuropsychologist, Dr. Eino Partanen (via Aptaclub U.K.). In addition to hearing muffled noises, "[The babies] hear [sound] in a different way than we do. The womb is filled with liquid. Sound isn't transmitted through air but through water ... There's a different feeling to the sound as well. If you think of what you'll be hearing underwater, that's the sort of environment the baby is in," explained Dr. Partanen. 

What should you be saying to your baby?

While it's perfectly reasonable to sing and speak to your baby throughout your pregnancy, a 2012 study published in Acta Paediatrica found that fetuses can recognize and learn the specific sounds of their native language based on what their mothers say to them. 

Co-author of the study and co-director of the Institute for Learning and Brain Sciences, Patricia Kuhl, told the  University of Washington, "The mother has first dibs on influencing the child's brain. The vowel sounds in her speech are the loudest units and the fetus locks onto them." There is also some research to back the idea that babies respond most to their mother's voice. They can also remember some of the words said to them while inside the womb, after they've eventually made their way to the outside world, per Verywell Family. Some mothers may worry that loud noise could affect the baby's hearing in any way. But unless you're exposing the little one in your womb to prolonged loud noise (eight hours or more a day), consistently, you don't have to worry about the occasional rock concert or loud party you attend. 

All in all, it pays to speak to your unborn child. So don't worry about whether or not it looks weird or if you're wasting your time. Your baby is finding comfort in your voice — and you're also bonding with your child long before they make it to your arms.