CHRONOLOGICAL AGE: How old a child actually is. Time since the child was born.
HEARING AGE: Time since the child has been receiving auditory input through appropriate amplification. Time since the child received hearing aids and/or cochlear implants.
For example: “Susie” was born August 21, 2001. Today is August 21, 2008. Susie’s chronological age is 7-0 (seven years, zero months). If Susie received a cochlear implant at 13 months of age (on September 21, 2002), her hearing age is 5-11 (five years, eleven months) or one year and one month less than her actual, chronological age.
BUT is this really the case?
Did you know that babies’ ears (the physical structures) start to develop around 18 weeks after conception? The physical parts of the ears are fully formed around 25 weeks post-conception, but babies begin to HEAR only 18 weeks after being conceived! So, by the time a child breathes its first breath after a typical 40 week pregnancy, that child already has 22 weeks, or over FIVE MONTHS, of hearing experience. In the womb, a child can hear the mother’s blood circulating and the sounds of digestion, and also sounds from the outside world, like parents’ voices and music. Unborn babies even begin to recognize their mothers’ voices around the 25th week of pregnancy. (See HERE for these great facts and more about human development.)
Unborn babies come into the world with over five months of hearing experience, if they are able to hear. This pre-exposure to the outside world, one that is loud and full of noises, helps hearing children with sensory integration (dealing with the overwhelming flood of sensory stimuli that are part of our world each day). Think about it — as a hearing adult (or a deaf adult with listening and spoken language training) — you are able to attune to the sounds in your environment, to focus on the things that are important (speech) and block out the sounds that are unnecessary distractions (the washing machine humming in the background). Hearing babies have a head start on learning to listen, and learning how NOT to listen. They have already had five months to “practice” navigating the world of sound.
This is why early detection of hearing impairment is crucial, and early amplification is a MUST. Babies can’t wait! If a deaf baby is identified at 3 months and receives hearing aids by month 6, they have already missed out on ELEVEN months of hearing experience. This is not to say that all hope is lost. Obviously, children identified much, much later have been successful learning to listen and talk (think about the days before newborn hearing screening, digital hearing aids, and cochlear implants — deaf children learned to talk then, under much tougher circumstances), just to emphasize the importance of getting your deaf child access to sound as soon as possible. The sooner you start working on listening and spoken language, the better chance you have of closing that gap!
TO LEARN MORE… Carol Flexer, Ph.D., is one of the biggest names in the field of auditory brain development, especially for deaf children learning to listen and speak. HERE is her personal website, and HERE are some fantastic quotes, words of wisdom, and pieces of advice from her books and public speeches.