Our hearing or auditory system can be broadly categorized into two parts- peripheral and central. The peripheral hearing includes the outer, middle, and inner ear. The outer ear consists of eardrum, auricle and ear canal. Middle ear contains malleus, incus and stapes. These three small bones are collectively denoted as ossicles. Malleus connects to the eardrum linking to the outer ear and the stapes connects to the inner ear. Inner ear has cochlea that is further connected to the central hearing system by auditory nerve. Cochlea consists of several special fluids which play an important role in hearing mechanism. The central hearing system consists of the auditory nerve and an incredibly complex pathway through the brain stem and onward to the auditory cortex of the brain.
Sound waves or simply the vibrations in our surroundings are collected by the auricle and are further channeled into ear canals. These sound waves vibrate the eardrum. Now, these eardrum vibrations are moved to the ossicles present in middle ear. From here vibrations are transferred to the cochlea in the inner ear.
Cochlea consists of thousands of hair cells that are sensitive to a wide range of such vibrations. High pitched sounds stimulate hair cells in lower portion of cochlea whereas the low pitched vibrations stimulate hair cells in the upper part. After detecting the frequency or pitch of a sound, each hair cell generates nerve impulses that are transferred immediately along the auditory nerve.
Auditory cortex is the hearing center in the brain. Here several such vibrations are converted into meaningful sound. This whole process takes place within a fraction of a second.
Ottorhea is a kind of ear-discharge (release of any fluid) from ear. Our ears release ear wax that is oil produced naturally by our body. This ear wax prohibits the entry of dust, bacteria and other foreign materials from entering into the ear.
Apart from this, other abnormalities like ruptured ear drum lead to drainage of blood from ear. This is an indication that your ear has undergone an injury or severe infection.
Middle ear infection
Also called as ottis media, this a common reason of ear discharge. It takes place when foreign agents like viruses or bacteria enter into the middle ear. As the middle ear is positioned behind the ear drum, any infection in the middle ear can lead to accumulation of fluid in ear drum. Over accumulation of fluid results further into ear discharge.
Trauma to the ear canal can also result into ear discharge. Sudden increase in pressure which usually takes place while flying or scuba diving is too a major cause of ear-trauma, causing ear drum to rupture. Acoustic trauma is caused due to extremely loud noises.
Also called as ottis externa , it takes place due to the entry of fungus or bacteria into ear canal that further results into a severe ear infection. It usually takes place when someone spends long span in water as moisture in ear canal can damage it.
Cochlear implant is helpful in partially restoring hearing. It is basically an electronic device that electrically stimulates the cochlear nerve (the nerve for hearing). It is a boon for the people who have severe hearing loss from inner-ear damage who are no longer helped by using hearing aids. An ordinary hearing aid just makes sound louder whereas a cochlear implant improves the ability to understand the speech. When a person struggles to understand speech, even with appropriately fitted hearing aids, a cochlear implant should be considered.
When do you need cochlear implant?
If you suffer through a major hearing loss and experience following conditions, then a cochlear implant can be quite helpful.
Hearing with a poor quality
Miss half or more of spoken words, without lip reading, even when wearing hearing aids
Not helped by other hearing aids
Dependent majorly on lip reading.
Improvements observed in people who have undergo cochlear implant:
Ability to find where sounds are coming from
Sense distinct sounds like footsteps or a phone ring.
Ability to listen in a noisy environment
Understand speech with less need to lip read
Enjoy television programs music and funny conversations.
The audiology vertical at AHRI Gwalior is the best institute in the region to undergo cochlear implant. With a team of highly qualified and well-experienced doctors, the institute offers diagnostic evaluations to people having speech, hearing, language, and communication difficulties. It is committed to ensuring excellent outcomes for the patients by the effective use of technology, taking care of their satisfaction and safety as well.
Being pioneered in Madhya Pradesh, the audiology vertical at AHRI Gwalior provides the best cochlear implant accompanied by the best possible care, and that too at nominal expenses.
A cochlear implant is an electronic medical device that replaces the function of the damaged inner ear. Unlike hearing aids, which make sounds louder, cochlear implants do the work of damaged parts of the inner ear (cochlea) to send sound signals to the brain.
Most important thing is early diagnosis. Management of deaf and mute child should be started as early as possible. Success of cochlear implant is more if it is done by the age of 3years. Success rate decreases with advancement of age of child.
How we hear?
The eardrum vibrations caused by sound waves move the chain of tiny bones (the ossicles – malleus, incus and stapes) in the middle ear transferring the sound vibrations into the cochlea of the inner ear. This is where the streams of nerve impulses are converted into meaningful sound.
Parts of ear:
Outer Ear :
Middle Ear: Converts sound waves in to vibrations.
Inner Ear (Cochlea): converts vibrations into electrical impulse. Theses electrical impulse travel to brain via nerve of hearing (Cochlear nerve)
What is cause of Hearing Loss in children?
As the cases of children being unable to hear pile up in Gwalior, it is necessary to know what causes the loss of hearing at such an early age. In children hearing loss can be congenital (from birth) or acquired (after birth). Acquired can be due to various infections or trauma, etc.
Hearing loss can also be classified as per language development as follows
Pre-lingual –hearing loss developed before child could start speaking, it can be either congenital (from birth) or acquired (after birth).
Post-lingual – hearing loss developed after child started speaking. It means it is acquired.
Cause of hearing loss is any defect in the transmission of sound through the ear. It can be
Conductive – Caused by defect in middle or external part of ear. It can usually be treated by some medications. Less frequently a surgery is required to correct this type of hearing loss
Sensory-neural – Caused by defect in nerve of hearing or cochlea. Mild to moderate hearing loss can be treated by hearing aid whereas severe to profound hearing loss requires Cochlear Implant surgery
Burden of Hearing loss?
In US Significant bilateral hearing loss is present in ~1 to 3 per 1000 newborn infants in the well-baby nursery population, and in ~2 to 4 per 100 infants in the intensive care unit population.
In India, 63 million people (6.3%) suffer from significant auditory loss. Four in every 1000 children suffer from severe to profound hearing loss. The estimated prevalence of childhood onset deafness to be 2%
How to assess Hearing loss in a new born?
Detection of infant hearing loss requires universal screening of all infants. Screening by high-risk registry alone (eg, family history of deafness) can only identify ~50% of newborns with significant congenital hearing loss. Reliance on physician observation and/or parental recognition has not been successful in the past in detecting significant hearing loss especially in the first year of life.
Tests for screening include otoacoustic emissions (OAE) and auditory brainstem response (ABR / BERA). Both test are noninvasive, quick, and easy to perform, although each assesses hearing differently. Aim is to initiate necessary intervention by 6 months of age.