Originally written for Sound In Fun! in 2018.
Some websites say to avoid music like heavy metal or rap during pregnancy and only play gentle music (like classical) to not startle your unborn baby. I’ve seen references to “research” but I can’t find any real studies about the effects of listening to dissonant, “harsh” or atonal music during pregnancy.
Based on what I can find in research (and knowing about auditory science), there are no limitations to what you listen to. One study advised carrying phones in a chest pocket or purse because a mom’s cell phone can startle her baby. Even then, the baby gets used to sounds over time.
They also can’t hear a lot of what you’re listening to because there’s a noise party going on inside the body. You heart beat, blood flow, intestines – these all make noise inside your body. Some studies show this is as loud as 90 dB (the equivalent to a hair dryer or kitchen blender). In fact, rap and heavy metal may help calm a colicky baby after birth because the rhythm and noise may be familiar to what they experienced in the womb.
At 32 weeks, a baby sleeps 90-95% of the time. That’s awake 1.2 hours a day total (spread over 24 hours). Closer to birth, they sleep 85-90% of the time. Even if your loud music wakes them up it probably won’t keep them awake long.
What Babies Can Hear
An expecting mom is very aware of her baby’s movements. During pregnancy with my son, I could tell the difference when he was startled versus excited. When I was at work listening to loud audio (as part of my job), my son would get excited by low frequencies – especially bass/subwoofer, loud drums, or a male coworker who laughed with a booming voice.
If your goal is for baby to listen to music, low frequencies reach the womb easier than high frequencies. Music like R&B, hip-hop, or EDM may actually have more low frequency information than other music – assuming you are listening with speakers that have low-end. Most tablets or mobile devices can’t do that.
Listen to Music for You
If a pregnant person is feeling relaxed, that can have a positive affect on an unborn baby. Babies can feel and remember their carrier’s emotional state. If a mom doesn’t like classical music, is it going to be relaxing for her? If listening to heavy metal makes a pregnant person happy and there’s no perceive any distress from the baby, power to you, Mom. Dancing and movement might even put them to sleep.
f you’re concerned about loudness or disrupting your baby, turn it down, listen on headphones (on your ears – not your belly).