Hearing Loss in Infants
As a father, I can attest to the fact that there is no better sound in the world than a child’s laughter and one of the greatest feelings is the excitement that comes from a toddler when they hear your voice. Many of us take these kinds of sounds for granted as 1 in every 250 children born in Ontario have some form of hearing impairment. While hearing loss as an adult is troublesome and perhaps annoying to a significant other, infant hearing loss can lead to problems with language as babies learn to speak by listening to the sounds around them. They say language is “caught, not taught.”
The Southwest Region Infant Hearing Program (IHP) automatically screens newborns for hearing deficits. Screening involves two tests where a small earphone is placed into the ear and soft music is played. In the first test, the ear’s response is measured and in the second, small electrode pads measure the brain activity. Problems with these tests lead to a referral to an audiologist (an expert on hearing who can further evaluate).
How do we hear sounds, you ask? Sound moves away from the source through tiny vibrations or waves (much the same as when you throw a rock into a pond, the waves ripple from the splash). The closer you are to the source, the stronger or louder the sound and it gets weaker as you move away. The ear catches these vibrations and amplifies them as they are passed into the inner ear to an organ called the cochlea. This small snail shell looking organ contains tiny hairs which vibrate in response to the sound waves and generate electrical signals that are sent to the brain by the auditory nerve. The brain receives these signals and recognizes them as the sounds we hear. Hearing loss occurs when any part of the system is disrupted.
Hearing aids are devices that amplify the sound to allow a person with hearing loss to regain function. Tiny microphones collect sounds, and these are then amplified and sent to the receiver which acts as a tiny loudspeaker. This amplification allows for the hairs in the cochlea to sense the vibrations and send a signal to the brain. Sometimes there is damage to these tiny hairs and a cochlea implant is then used. This device captures sound and rather than simply amplifying, it converts those sounds into electrical signals that are sent directly to an implant in the auditory nerve. No matter what device is used, hearing is never fully restored to that of a person without hearing loss and therapy with a speech and language pathologist is required to help with language development. Never take your hearing for granted, and if you are a parent living with a child with hearing loss, know that there is hope! Take care of yourselves and each other.
-Steve Bond, Pharmacy Manager