Tuesday, August 9, 2011

Your Baby’s Senses: Hearing

Imagine what it must have been like during those first moments when your baby came into the world blinking against the light, his muscles tensing as a flood of new sensations washed over him. Suddenly, he was hearing the sounds of excited voices, seeing the contours of your face, feeling your fingers stroke his back, smelling the air around him, and tasting your salty skin as he nuzzled in as close to you as he could. Because babies can’t use words to communicate with us, many parents wonder how well babies can use and learn from their senses. In this new series, we’ll share what we’ve learned about the amazing process of sensory development in babies. We’ll start with your baby’s sense of hearing.

The Sounds Inside

The physical structures needed for hearing (babies' ears and all the structures inside) develop entirely before babies are born. During the third trimester, the auditory nerve is developed well enough that the babies can hear (and remember) many of the sounds they hear daily from the world outside the womb. Researchers have shown that newborns are familiar with the voices of their mothers and fathers and that they are particularly interested in hearing human voices as compared to other sounds. Brain development involved in the discrimination and isolation of sounds continues well into the baby’s first year of life.

Newborn Hearing

By the time they are born, babies’ sense of hearing is one of their most developed sensory systems. While newborns can hear many of the sounds around them, they may not hear the quieter ambient sounds right after birth. If you speak to your newborn while he’s alert and not distracted, he will become more focused, quieter, and slow down his movements. He may attempt to turn toward the sound of your voice but some babies take a little time to do so easily. Babies do much better in responding to sounds when they are held in a relatively upright position and calm and alert. If you have any concerns about your baby's hearing, you should speak with your doctor.

Making Sounds “Fit” Babies' Needs

Mothers automatically use a higher pitched, lilting voice when speaking to their babies – this is called “Motherese” and we’ve talked about the importance of using this kind of communication in earlier posts. You’ll find that babies prefer “Motherese” when they are alert and lower softer tones when they are drowsy. Of course, dads can use their own type of "Fatherese." When dads raise the pitch of their voices and use longer tones as they speak, they will find that they can keep their infants’ attention a little longer. Researchers also have found that babies seem to prefer “happy voices” versus those that sound more neutral or negative. Both parents can match the tone and pace of their voices with babies’ readiness and interest by watching for cues. By 4 to 6 weeks of age, your baby will try to vocalize back to you, first making noises simultaneously as you speak and then by taking turns with you. By 5 months, babies have learned to identify the peculiarities of their own language and between 6 and 8 months they are able to tune out sounds that are not used in their own language. These early steps are important for babies' development of language.

Next time: More about your baby’s senses


1. Berger KS. The Developing Person. New York, Worth Publishers, 2003.
2. Nugent JK et. al. Understanding Newborn Behavior and Early Relationships. Baltimore, Paul H. Brookes Publishing, 2007.
3. Lester BM and Sparrow JD (Eds). Nurturing Children and Families. Malden, MA, Wiley-Blackwell, 2010.


  1. Do you know very much about the effects of white noise on babies? I've heard that it can slow down their hearing development? There are so many devices sold though, and not much mentioned. We've been using it in our room with our 4 month old for at least 2 months now and just read that. I tried to do some research, and only found one study on some mice in the 90's.

  2. We'll check this out and see what we can find for you. Certainly, if the white noise is prolonged or too loud, you run the risk of preventing babies' exposure to normal noises or damaging their ear structures. That is probably what they did to the poor mice. Stay tuned!