SPEAKING OF HEARING
LEARN MORE ABOUT HEARING TROUBLE
The ear is a sophisticated organ that transmits the sounds we hear into electrical impulses that are interpreted by the brain. The process of hearing and interpreting sound is accomplished at a fantastic speed. To achieve this remarkable feat, each part of the ear - outer, middle and inner ear - fulfills a specific function.
How we Hear/Transmission of Sound ?
Let us look at the ear anatomy
The funnel shaped outer ear functions to collect sound waves which are then transferred through the ear canal to the eardrum.
Sound waves cause the eardrum to vibrate. This vibration stimulates the movement of the middle ear bones, which are attached to the eardrum on the middle ear side. These bones amplify the vibrations received by the eardrum and transmit them to the oval window, a small membrane on the cochlea, which separates the middle ear from the inner ear.
On the cochlear side of the oval window is fluid (or lymph) which fills the cochlea. Vibration of the oval window causes pressure waves within the cochlear fluid. The pressure waves stimulate movement of thousands of acoustic hair cells in the cochlea, converting the sound signal into electrical stimuli via neurons. These electric stimuli are transmitted to the brain via the eighth cranial nerve, or auditory nerve. In the brain these stimuli are processed and are perceived as sound.
Discover the ears anatomy
Outter ear
The outer ear is composed of the pinna, the familiar visible portion of the ear, and the ear canal. The shape of the outer ear serves to give preference to sounds originating from the front. The shape of the ear canal serves to enhance frequencies that are important for hearing speech.
Middle ear
The middle ear consists of the eardrum, or tympanic membrane, and three tiny ear bones, or ossicles. The ossicles are the smallest bones in the human body. Although named the malleus, incus and stapes, they are often referred to as the hammer, anvil and stirrup because of their characteristic shape. Besides their role in the transmission of sound, these bones help to protect the ear from damage by constricting and limiting sound transmission when sound is too loud. The middle ear also contains the Eustachian tube, which connects with the throat, and serves to ventilate and regulate pressure in the middle ear.
Inner ear
The inner ear is composed of the semi-circular canals, which are important for balance, and the fluid-filled, snail-shaped hearing organ, the cochlea.
Causes of hearing loss
There are many causes of hearing loss. In many cases, hearing loss happens gradually and generally worsens with age. Hearing loss caused by aging is known as presbyacousis. Disease, infection, heredity, head trauma, exposure to loud noise and certain medications may also cause hearing loss. In some cases, the cause of hearing loss is unknown.
Les autres causes de surdité
Au delà de la presbyacousie, il existe d’autres facteurs pouvant entraîner une altération des capacités auditives comme l’environnement moderne avec son lot de nuisances sonores, ou encore certaines affections ayant des répercussions directement sur l’audition. Les causes peuvent aussi être d’origine congénitale ou héréditaire. Un traumatisme causé par un accident peut également causer une surdité. Mais le phénomène le plus alarmant aujourd’hui est sans conteste l’évolution des troubles auditifs chez les jeunes, due à l’écoute de baladeurs à forte puissance et à l’exposition prolongée à des niveaux sonores dommageables lors de concerts assourdissants.
Types of Hearing Loss
SENSORINEURAL HEARING LOSS
Sensorineural hearing loss is caused by inner ear damage. Sometimes referred to as "nerve losses", these comprise 95% of all hearing losses. Some causes include presbyacousis/aging, noise exposure, heredity, viral infection to the brain such as meningitis, and in rare cases, ototoxic medications. Although there is no cure for sensorineural hearing loss, advances in hearing aid technology can help the vast majority of people with this type of hearing problem.
CONDUCTIVE HEARING LOSS
When sound transmission through the outer or middle ears is prevented or impaired, this is known as a conductive hearing loss. Some causes of conductive hearing losses are obstruction of the ear canal by impacted earwax, head trauma affecting the middle ear bones, perforation of the eardrum, fluid build up in the middle ear, and otosclerosis (a stiffening of the middle ear bones). About 5% of hearing losses are conductive in nature, and many can be treated medically.
MIXED HEARING LOSS
A mixed hearing loss is one that has both sensorineural and conductive components.
Protecting your hearing
Exposure to excessive noise during work or leisure activities can increase a person's risk of hearing loss and contribute to worsening an already existing hearing problem. A continuous exposure of 85 decibels (dB) will begin to have a detrimental effect on our hearing. An example of this would be the noise of a street with constant heavy traffic. If the exposure to loud noise lasts for a long time, the cells responsible for our sense of hearing will be irreversibly damaged. Doctors consider exposure to loud music, such as a rock concert or via headphones, to be particularly dangerous since the sound intensity can sometimes reach 110 - 120 dB. The traumatic effect of a sudden loud sound such as an explosion can also permanently damage hearing.
Other activities that may cause hearing loss over time include: use of a personal radio/CD player/stereo at a high volume; use of firearms; operating heavy machinery; use of power tools. The good news is that the noise in these cases is usually easily managed by turning down the volume or by wearing ear protection. Federal regulations govern allowable noise levels in the workplace, as well as the employer's role in providing ear protection. More information on this subject can be found at www.osha.org. In addition to using ear protection, those who are regularly exposed to noise should have their hearing tested regularly.
Certain medications are toxic to the ear. If you have a hearing loss, be sure to inform your doctor of your condition before beginning any new medications. There may be instances where other medications which are not toxic to the ear can be substituted.
How loud is too loud
A general rule of thumb is if you have to raise your voice to be heard over the music/noise, it is too loud. According to the National Institute on Deafness and Communicable Diseases, noises above 85 decibels can cause hearing damage.
Ear Protection
Since there is no cure for noise-induced hearing loss, prevention is the sensible alternative. Modern devices which protect your hearing, from commercially available earplugs to custom-made earmolds with various filter systems, can give effective protection against noise.
If you are exposed to continuous noise in your leisure activities or at work, contact us for advice on the latest methods of hearing protection which would provide the most benefit and best suit your hearing needs.
People who suffer from tinnitus continuously or sporadically hear sounds, noises or whistling without external stimulation. It is estimated that 600 000 Quebecers suffer more or less severely from this condition.
It is very complex to identify the exact cause of tinnitus. There is virtually no medical treatment to solve this problem. However, there are psychological therapies to cope with tinnitus. A strong collaboration between the audioprosthetist, the ENT doctor and the audiologist can make a great difference in helping the patient to live with this condition.
Hearing specialist
The audioprosthetist is a listener and advisor
Your audioprosthetist from Les Centres Masliah is a health professional. His main task is to improve your hearing capacities. Relying on your ENT exam results, and after a deep discussion with you, he helps with the choice, adaptation and efficiency control of your hearing aids. He will explain how to use them and to learn how to hear again. In order for you to benefit permanently of the best hearing comfort, your audioprosthetist from Les Centres Masliah regularly performs a thorough routine check-up of your hearing aids and verifies they are well adjusted.
ENT doctor: Hearing specialist
The Ear-Nose and Throat (ENT) doctor specializes in the examination and medical or surgical treatment for the nose, throat and ear. He holds an important role in informing the patient and his family. During consultation, he proceeds to hearing examination, completes a medical hearing report and establishes an accurate diagnosis on the hearing deficiency. These various tests also allow him to determine the level and type of deafness and verify there is no contraindication for prescribing hearing aids.
The audiologist is a human communication disorder professional
The audiologist studies, examines, evaluates and treats hearing disorders using the required assistive listening devices. He generally works in a hospital environment and possesses a solid training in hearing evaluation and re-adaptation to the world of sounds.
The speech therapist is a human communication disorder professional
He studies, examines, evaluates and treats voice, speech and language disorders and he uses the required assistive listening devices.
