What are the different hearing disorders? What causes?

In France, 25% of adults are affected by a form of hearing loss, indicated theInserm in 2022. The term “hearing impaired” is used to refer to a person who is not able to hear as well as a person with normal hearing, the threshold being 20 decibels (dB) of loss in the better ear. In addition to the person who hears badly, there is also the one who suffers from tinnitus, hyperacusis…

Disorders that can harm hearing are very numerous and are growing as our environment very often exposes us to amplified noises and sounds. In France, according to Inserm, deafness affects 6% of 15-24 year olds and more than 65% of people aged 65 and over. The level of hearing loss is classified in decibels (dB) of hearing loss by theHealth Insurance :

• the mild deafness : from 20 to 39 dB of loss. The person makes his interlocutor repeat as soon as 30 dB is lost, on high-pitched sounds;
• the moderate deafness : from 40 to 69 dB of loss. The 40 dB threshold is the first major level of handicap. Indeed, the person understands only if his interlocutor raises his voice. She is “hard of hearing”;
• the severe deafness : from 70 to 89 dB of loss. The daily discomfort is major;
• the profound deafness : more than 90 dB loss. The person no longer hears speech at all.

Hearing loss and deafness are not the only hearing problems. Tinnitus and hyperacusis are also included.

• L’hypoacusis or deafness : gradual or sudden loss of hearing
• The presbycusis : progressive age-related hearing loss. It generally begins from the age of 45/50 and first reaches the perception of high frequencies.
• L’hyperacusis : “The sound is distorted in frequency and intensity, this is a sign of a sick inner ear. People who suffer from it are not deaf but they hear too loudly. It is a social disease that we encounter from more and more often, linked to the use of headphones and surrounding noise. Thus, these cells of the inner ear, stimulated too hard and for too long, lose their ability to code the sound intensity”, developed by Pr. Darrouzet.
• The tinnitus : these are buzzing or whistling noises heard by the subject but which are not present in the environment. Tinnitus can be temporary or permanent, and has multiple causes.

Conductive hearing loss is due to damage to the structures of the outer ear and/or the middle ear responsible for “to transmit” the vibratory auditory message to the inner ear “any obstacle in the auditory canal, any lesion, interruption or even fixation of the chain of the ossicles, any lesion of the eardrum, any tumoral or inflammatory process occupying the middle ear creates conductive hearing loss”explains Vincent Darrouzet.

Perceptual deafness results from damage to the structures located downstream in the course of the sound message, i.e. theinner ear, the auditory nerve, the cerebral auditory pathways, and even more rarely the cerebral integrating centers. “Sensitive hearing loss affects the inner ear – in the vast majority of cases – or the auditory nerve or auditory pathways in the brain. They are mainly linked to genetic or acquired diseases of the hair cells of the cochlea, responsible for transform the vibrations of their eyelashes into nerve impulses. We have 16,000 in the ear, we are born with this capital and we die with what is left, they do not regenerate”, adds the head of the ENT department of the Bordeaux University Hospital.

“Central auditory disorders relate to a lack of cortical integration : the message arrives but it is misused. The origin can be genetic, psychological or psychopathological and very rarely of vascular origin.lists the professional.

• Sudden or gradual loss of hearing
• An amplified and/or distorted perception of sounds
• A clogged ear sensation
• Tinnitus which can also be a symptom in the context of hyperacusis in particular

“In the child, there is two main causes of deafness“, notes Professor Vincent Darrouzet, ENT, head of the Surgical Specialties and Dermatology Center at the Bordeaux University Hospital.

• The genetic deafness : “it is more or less serious, more or less precocious, bilateral, and progressive”, describes ENT. “In France, every year, nearlya thousand newborns (0.25%) are affected by deafness. In 40% of cases, the disorder is severe and profound, with serious consequences on the acquisition of oral language and on the socio-emotional development of the child. Three quarters of these deafness are of genetic origin (linked to an anomaly of the ear), the others being acquired during pregnancy or during the perinatal period”. details theInserm.
• The seromucous otitis : “Seromucous otitis media is a chronic inflammation of the middle ear lining which is manifested by an effusion of liquid locked behind an eardrum and which lasts more than 3 months. It is the leading cause of consultation, antibiotic prescription and surgical intervention in children in developed countries. It affects nearly 20% of children under 2 and 16% of children under 5.explains the High Authority for Health. “Otitis is very common in children, much less in adults. They can cause hearing loss due to the liquid accumulated behind the eardrum”, notes our expert.

The treatments vary depending on the type of deafness and especially of the identified cause. The earwax plugs must be removed, infections treated… Certain anatomical problems are sometimes accessible to surgery. If the problems persist, a hearing aid may sometimes be offered. “In children, particularly affected by seromucous otitis and possible associated deafness, the treatments consist of paracentesis, surgery which allows to suck up the excess liquid, the installation of diabolo or yoyo often associated with the removal of vegetation”, adds Vincent Darrouzet. In unaidable bilateral congenital total sensorineural hearing loss, a cochlear implant will be offered to families. Alternatively, in case of refusal of the establishment, the learning of sign language, associated with an adapted schooling, can make it possible to limit the exclusion generated by this handicap. “For non-deaf hyperacusics, unfortunately there is no evaluated treatment to offer them. These are patients who almost always wear earplugs to protect themselves and who end up gradually isolating themselves”laments our expert.

the general practitioner and especially ENT, specialist in hearing disorders, are the privileged interlocutors. The general practitioner will most often refer his patient to an ENT if he cannot identify or treat the cause of the hearing problems.

The consequences of hearing disorders are multiple, first and foremost theexclusion from society. “Hyperacusis and tinnitus are easily isolated on the social level. They are very destructuring diseases on the psychological level, emphasizes Vincent Darrouzet. In the case of a child who is born deaf, the deafness requires rapid correction so as not to slow down the construction of language during the very first years of life. Quickly, it is already too late. The brain does not build, the auditory cortex does not form. The sound exists but it is not integrated by the brain”, explains the ENT surgeon. In the elderly, treating deafness early also means preventing desocialization and slowing down cognitive loss.

Thanks to Professor Vincent Darrouzet, ENT, head of the Center for Surgical Specialties and Dermatology at the Bordeaux University Hospital.