AUTHOR: Cassy Christianson

How Your Child’s Sensory System Develops

What is sensory development? In general, it refers to the maturing of the five familiar senses: hearing, smell, taste, touch, and vision. It also involves the way your baby or child’s nervous system receives input from these senses and then forms an appropriate motor or behavioral response. This is known as sensory processing or sensory integration.

Besides organizing the input from the five basic senses, sensory processing also focuses on the sensation of movement. Your baby explores and discovers the world through her senses. Babies are born with most of these senses nearly fully developed. But some subtle changes occur through the end of a child’s second year.

A problem with just one sensory system can greatly affect your child’s overall health and development. For example, when a baby’s hearing is not optimal and remains uncorrected, her speech and language development, communication, and learning may be delayed. You will want to understand how your child’s sensory systems develop. And be aware of any signs of concern. This will help ensure your child reaches her full potential.

What changes can I expect in my baby’s sensory development?

It’s helpful to watch for these changes in your child’s sensory development.

  • Hearing: Newborns can’t hear certain very quiet sounds. But, for the most part, their sense of hearing is already well developed. After about three months, sh e will show you she hears a sound by turning her head toward the direction of the sound. By four to eight months, she will hear the full range of sound frequencies.
  • Smell: A newborn’s sense of smell is so acute that she can already tell the difference between the smell of her mother’s milk and that of another mother. Researchers conducted experiments where two breast pads (one from the infant’s mother, the other from another lactating mother) were placed at the sides of the newborns’ heads. The babies reliably turned towards the breast pad of their own mothers. By about age five, your child can identify some foods by smell.
  • Taste: A newborn can distinguish between sweet, salty, sour, and bitter tastes. She shows a preference for sweet taste, such as breast milk, and for salty tastes later on. Your baby will achieve a full sensitivity to taste by 12 to 19 months.
  • Touch: The term touch here is used to describe all of the physical sensations that can be felt through the skin. Touch is actually not a single sense, but several. There are separate nerves in the skin to register heat, cold, pressure, pain, and touch. At birth or shortly after, your baby can distinguish between hot and cold temperatures and feel pain. Your baby’s hands and mouth are especially sensitive to touch. Between one to nine months of age, she will be able to distinguish differences in textures with hands and mouth. As a preschooler, she will be able to distinguish size and shape differences by touch.
  • Vision: Newborns can focus on objects about eight to 15 inches away. By one month, she will see about three feet away. At birth, she has limited color vision. But by two months, she can discriminate between basic colors. She will achieve full color vision between four and seven months of age. Depth perception develops between three and seven months. It will achieve full adult acuity (20/25) during her second year.
  • Sensory Processing: Given all of the sensory information a newborn can take in, she must begin to develop her processing skills and learn how to use the incoming sensory information to effectively act on her environment. When overstimulated by all of this sensory information, an infant will need help to calm herself. As she matures, she will learn self-regulation and display the skills needed to calm herself. In tandem with developing better control of her motor skills, her system will be learning to process the sensation of movement coming from her body through the vestibular and proprioceptive nerve receptors. As she matures, she will then learn to use all of the sights, sounds, and other sensory information in the environment to explore and learn about herself and her world.