Do You Know At What Age Your Child Will Have Adult Level Hearing Abilities? The hearing system matures first within the ear, then the brainstem (channels information to and from the brain), and with time finally the cortex (the two sides of the brain that interpret and control most functions).
As the ear begins to develop, MRI studies show the presence of the organs of hearing and balance at about the fifth week of gestation. The outer ear and basic cortex are also visible. By the end of the 20th week of pregnancy, the structures of the inner ear nerves are completely developed to adult size.
The human inner ear is very small at about half the size of a pencil eraser. The brainstem, which carries information from the ear to the cortex, can transmit signals by about the 30th week of development. Around this same time, the cortex also becomes clearly visible. This rapid growth occurs because brain cells develop at a rate of about 250,000 cells per minute (Akerman S., 1992). That is fast!
Research suggests that an infant’s brain contains about 100 billion nerve cells. Even though at birth the hearing system is infantile, the brain can still learn speech sounds in any language. Refinement of speech, language, and hearing abilities continues to occur over time as a result of a maturing nervous system and sound experience. By adolescence, at about the age of 12, the connections between the right and left-brain are generally complete, signaling the final stages of maturity and hearing abilities are typically at adult levels.
Along the way, understanding a child’s environmental sound experiences can be very helpful in fostering brain development, not just for hearing sound and daily communication, but for cognitive processing. A musician’s brain is unique and developed. It is clear that music is food for the brain at any age. Therefore, without hesitation as a parent, I would include a music regime as part of any child development programming from birth or naturally at the fetal stages after the first trimester. The music should be age appropriate and not too loud. Remember that a fetus hears the mother’s low tone voice (primarily vowels) at moderately loud internal levels, but is protected from outside high tone sounds by the womb and does not perceive speech consonants (teeth, tongue, and lip sounds) such as the s, sh, ch, t, p, k, h, f, etc. because of development. I would not suggest that a fetus, infant, or child be exposed to a rock band, loud machinery such as a forging hammer, and especially no firearms . First, there is a startle effect that can be a negative experience, secondly, changes to normal heart rhythms can occur, and finally, loud sound causes hearing loss even in fetuses. Moderate levels of music should include both home and school, especially if the child is hard of hearing.