Your child’s hearing
To understand your child’s hearing loss, it helps to understand how we hear. In the particular case of children, it is also necessary to be aware of expected speech and language skills at different ages, since these are strong indicators of their hearing development. Inconsistency in age-appropriate language skills is also one of the usual symptoms of hearing loss. Hearing impairment in children can develop before, during and after birth, and with younger as well as older kids
How we hear
Delicate and soft on the outside, your child’s ear is actually a very sophisticated organ. Very simply put, it turns sound waves in the air into information in our brains — and sometimes emotions in our hearts. It can perceive sounds from barely audible to very loud, differentiate their loudness and distance, and pinpoint the direction of a sound source to an amazing degree of accuracy. The short movie on this page will clearly demonstrate how the children’s ear performs the wonderful task of hearing
The outer ear:
consists of the visible part of the ear, also called the auricle, and the ear canal. What we call ‘noises’ are actually just ‘sound waves’, which are transmitted by the air. Sound waves are collected and guided through the ear canal to the eardrum. The eardrum is a flexible, circular membrane that vibrates when sound waves strike it.
The middle ear:
is an air-filled space separated from the outer ear by the eardrum, or the tympanic (pronounced: tim-`pa-nik) membrane. In the middle ear are three tiny bones: malleus, incus, and stapes, often referred to as the hammer, the anvil, and the stirrup. They are collectively known as the ossicles. These form a bridge from the eardrum to the inner ear. The ossicles also vibrate in response to movements of the eardrum and in doing so, amplify and relay the sound to the inner ear via the oval window.
The inner ear:
referred to as the cochlea (pronounced: kohk-le-a), is similar in shape to a snail shell. It contains several membranous sections filled with fluids. When the ossicles conduct sound to the oval window, the fluid begins to move, thus stimulating the minute hearing nerve cells, called hair cells, inside the cochlea. These hair cells in turn send electrical impulses via the auditory nerve to the brain where it will be interpreted as sound.
Even the unborn child in the womb perceives sounds from the outside world; the unborn child reacts to sound as early as 24th week of pregnancy. However, the auditory paths mature completely only after birth; furthermore, this maturation process is fostered by acoustic stimuli.
Playful speech and language development
Hearing and perceiving acoustic signals is necessary for a child’s speech and hearing development. During the first babbling phase of speech acquisition, all children throughout the world exhibit roughly the same phonetic speech patterns. At the age of four to six months, the child’s sense of hearing really begins to influence further speech development. By the sixth month, the second stage of the babble phase usually begins. Children start to be aware of their own voices and thus experiment with speech. If a child does not begin to play with sounds and to produce syllables at this age, there might be a hearing impairment. Even with a mild hearing loss, a child may quickly lose interest in experimenting with different sounds.
Exploring and conquering the world
Not only speech acquisition, but also a child’s intellectual and personal development is closely linked to hearing and its development. The parent’s voice is a source of security and closeness to the infant. Even before the child learns to talk, he or she can differentiate between praise, approval or admonition in the melody of a parent’s voice. Much of what an infant knows of the world, he/she learns through hearing. The child’s ability to talk and communicate verbally depends on the ability to hear. To ensure a good start in life, it is important to see to it that pediatric hearing loss is diagnosed and treated at an early stage.