s per a recent census report 1 in 10 people in our country suffer from a hearing loss, the number is staggeringly high and there is a need to conduct a thorough hearing evaluation for all. Unlike eye sight, hearing problem is often detected much later and even when detected people tend to ignore it till it becomes severe.
We hear over different frequency ranges i.e. from 20hertz to 20000 hertz and the normal limits of hearing expressed in terms of decibels is placed at 20 as per Indian standards. If someone is not able to hear sounds at different frequency levels up to the level of 20 decibels, then the individual is said to have a hearing loss.
As normal speech conversation level is at 40-50 decibel, an individual with a mild loss is easily able to ignore his problem when it is at the moderate stage. Furthering the damage, the prevalent social stigma about hearing problems & hearing aids prevent the individual from getting his problem treated or even checked.
Before understanding any pathology associated to hearing, one must fully understand the anatomy and working of it. Let us therefore first understand how the process of hearing works:
The function of Outer Ear is to act as a funnel for sound waves from the environment thereby concentrating them from a relatively larger area i.e. the atmosphere into the ear canal. These waves then pass through the Tympanic Membrane or the ear drum making it to oscillate back & forth thereby passing the energy to the middle ear.
Middle Ear is where we have three bones namely “Malleus”, Incus & Stapes. These bones are attached to the tympanic membrane on the outer side and inner ear on the other. Once the sound energy passes though the tympanic membrane, it gets converted to mechanical energy in the middle ear thereby making the bones to vibrate.
The Inner Ear contains “Cochlea” which is studded with hair cells and contains a thick viscous fluid. It is here that the mechanical energy gets converted to electro-magnetic impulses through the motion of the fluid. The cochlea is attached to the auditory nerve which has a function to carry these electro-magnetic nerve impulses to the brain where we understand this energy as sound.
Tinnitus has so many complications, while numerous hearing disorders also have signs of simultaneous tinnitus, it is also not at all abnormal to have tinnitus without an ear disorder or hearing loss because there are many, many causes of tinnitus.