My eldest son just asked me a question, which I do not know the answer to, and my google-fu fails me. (It takes me to things like “do babies cry in utero” which isn’t the question.) The question is “do babies make noise in the womb?” We’ve pretty much decided that babies in the womb can’t make verbal noises involving the vocal chords because of the lack of air to vibrate vocal chords, but what about smacking lips, clapping, etc.? Do these things rely on air? And if they do not, does an in-utero infant have the strength to create noise? Also, could noise audible outside the mother’s body without equipment such as stethoscopes or dopplers be made?
They have the strength and dexterity for it as soon as they’re out; by that time they had it already, they don’t gain it at birth any more than a teenager gains the ability to think on the minute he turns eighteen. Once the kid is developed enough, it starts touching, opening and closing hands and eyes… Clapping is more difficult: how many newborns have you seen clap?
Good point. I’ve seen and heard newborns smack their lips though, as a hunger response. Does that noise require an air medium? I’ve had two kids, and one on the way, and though I’ve never heard a baby noise from my abdomen, I admit it never occurred to me to ask this before. Oldest boy has an interesting outlook on things.
Water absorbs noise quite readily, so something relatively soft like a smack can happen but just won’t be heard from outside; some of the noises the baby makes can be heard with a stethoscope, but you already said you weren’t interested in that possibility. And of course, they can’t belt a good yell until they’ve gotten air in their lungs.
Sound relies on a medium to transmit it. Liquids, being denser than air, are better at transmitting sound (and solids even more so); arguably if an infant in utero manages to clap hard enough then it could be heard outside the mother’s body.
Oh, and infants can cry in utero. My ex-wife is a nurse who has had OB/GYN experience; not only has she heard it happen, she could imitate it. Vocal chords vibrate just as easily in amniotic fluid as they do in air.
Yes, Olentzero, but an infant in utero is unlikely to clap. Try clapping or snapping your fingers underwater: it’s harder than in air.
They do laugh too.
Really? Could the mom hear it? I had never heard of that. How strange, but it seems plausible.
Towards the end of my wife’s pregancy, I was able to hear my daughter hiccupping now and again, but only with my ear against my wife’s abdomen.
TheKid had hiccups in utero. Her father tried to listen, got nothing. I can’t explain the feeling - very weird.
No clapping or finger snapping. She did use my ribs as a marimba, though.
Another fun thing to look forward to when I finally start a family. 
I’m skeptical. I won’t deny that your ex-wife thinks she heard something. However, a *sound *made by passing a liquid across the vocal cords? I’m doubting it. First of all, there’s still some question as to whether babies actually do “breathe” the amniotic fluid in and out. But also, the medium is so dense compared to air that I can’t imagine any substantial sound being produced. When we breathe in helium, for instance, and try to talk, the pitch rises considerably, merely because of the different density of helium vs air. If the medium were liquid, I’d guess that any sound that could be produced would be extremely low. Nah, this sounds very doubtful.
That’s odd. Because one of the score items on a standard fetal biophysical profile via sonogram is whether or not the fetus engages in “practice breathing” motions. It seems strange that such a standard test would include a benchmark for something about which there is “still some question”.
All three of my kids hiccuped in utero, but girl#1 in particular. Not only did she often get hiccups, but she had them in labor, and they made a rather distinctive sound on the fetal monitor tracing, so much so that they interfered with recording her heartbeat for a time.
It looks like you’re more on track than I am. It appears, from rudimentary Googling, that every case of an infant audibly crying in utero has happened during birth, when the water has already broken and air has entered the vagina and/or uterus. This is most likely what my ex encountered. To be honest, I never did ask her about the circumstances; I just kinda assumed it was late pregnancy rather than birth.
Wow, thanks for all the info, everyone. I really appreciate it. I’ll be talking to oldestboy tomorrow to give him the consensus.
Im about 36 weeks pregnant and I believe u can hear sounds from the baby coming from the womb because when I lay down and relax I can hear the sound that sounds like shes sucking on her thumb or sometimes it sounds like a whimper… I recorded it so my fam and everyone thinks its the baby haven’t got to the doctor to ask them yet… but will let u guys know!