What is the Developmental Process of a Babys Hearing?

A baby's hearing gradually develops over time. Initially, newborns are not very sensitive to sound, but as their bodies continue to develop, they become increasingly responsive to auditory stimuli. Understanding the hearing development process is crucial to ensure that a child's hearing remains intact or to detect any issues promptly. So, what does the hearing development process look like for babies? Let's take a closer look.

1. At Birth: Research suggests that newborns already have the ability to sense external sound waves. However, due to the absence of air in the eardrum chamber, their hearing may be relatively poor.

2. 3 to 7 Days After Birth: The auditory system of newborns becomes quite acute within a few days of birth. When someone speaks or makes a noise near their ears, it can trigger a series of stress responses such as opening or closing their eyes, startling, or changes in breathing rate. Parents who have cared for infants may have observed that babies often extend and straighten their arms, open their fingers, and then flex their arms in a hugging reflex when they suddenly hear a sound. These phenomena can be used as reference indicators for newborn hearing tests.

3. 3 to 4 Months Old: Over time, these initial responses gradually fade, and babies begin to show directional responses to sound. They will turn their heads or shift their gaze in the direction of the sound. Parents can test their child's hearing by observing their conditioned responses. For example, playing music before feeding can help detect hearing function. After about a month, a hearing-normal baby will respond to the music by sucking. Similarly, many parents make a specific sound when helping their baby urinate. Over time, the baby will associate this sound with urinating and respond accordingly. If these conditioned responses do not develop, parents should be alert to potential hearing issues.

4. 5 to 6 Months Old: At this stage, the hearing and vision reflexes are well-established. A hearing-normal baby will often turn their head to locate the source of a sound and can distinguish familiar voices.

5. 8 to 9 Months and Beyond: By around 8 months, if a baby's hearing is normal, they will begin to understand the meaning of simple words. For instance, when asked "Where's Mommy?" they will turn their gaze to their mother. At 9 months, they can locate sound sources from different angles. By 1 year, they can recognize their own names, and by 2 years, they understand simple instructions. By 4 years, their auditory development is relatively complete.