The sound wave is captured by the external pavilion of the ear. It is then guided to the ear drum by the external auditory conduct. These three structures constitute the external part of the ear. The ear drum’s vibrations then trigger the movement of the bone chain (constituted of three bones: the hammer, the anvil and the stirrup) which is the principal element of the middle ear. The sound wave is converted into a mechanic vibration.  The last link of the bone chain is the stirrup (the smallest bone in the human body) that transmits the movements to the liquids of the internal ear. This mechanical vibration is therefore transformed into a nervous influx, capable of being decoded by the auditory centers. This information is analyzed by the sensorial cells (or hair cells), disposed in range within the cochlea (principal part of the internal ear) who are responsible of catching the liquid movements
The nervous influx generated by the hair cells is then decoded at different levels of the auditory centers: each level playing a role (perception of the timbre, of the tempo…).
All the complexity of the human hearing system is based on the proper functioning of this range of 3500 cells of the internal ear,  that constitute the heart of the auditory perception.

Presbyacusis is a natural process linked to the aging of the internal ear. It results in a progressive loss of audition. Some signs do not lie: The patient starts losing some sounds like bird chipping and clock ticking; he also experiences difficulties in understanding speech when the environment is noisy and tends to ask the other speaker to repeat his phrase. Presbyacusis also causes discomfort whenever having a multilateral conversation, because it needs a constant effort and attention. A tendency to increase the TV and radio sound also occurs causing complaints from the patient’s entourage. On a longer term, the person suffering from this handicap will stop enjoying social activities and presbyacusis will result in a progressive isolation of the subject. This sound alteration does not affect all auditory frequencies alike. Generally acute frequencies are the first to be lost (An acute sound producing an acute frequency). Bass sounds are usually better preserved. If you are experiencing one or many of these symptoms, you should make an immediate appointment with your Oto-Rhino-laryngologist (ORL) in order to carry out an auditory exam, the doctor will test your audition, frequency by frequency in order to evaluate your level of hearing discomfort. He will then be able to determine if an auditory prosthesis will help ameliorate your hearing.

Two principal factors can help provoke presbyacusis by accelerating the aging process of the cellular capital of your internal ear: heredity and excessive exposition to noise. Heredity intervenes directly in the aging process since it can increase the fragility of the external hairy cells. Excessive exposition to noise (either for professional or leisure reasons: hunting, walkmans concerts…) can cause a premature diminution of the cellular capital. Presbyacusis will just happen earlier, without any previous immediate signs. Auditory prosthesis are the only available way to correct the auditory loss linked to age (or presbyscusis) they allow a proper adaptation while amplifying the sound according to the reached frequencies whereas an auditory helmet will amplify all frequencies alike, causing a neat hearing discomfort.

The hearing prostheses can be ranked according to two criteria:

1. The digital technology:: This recent technology offers high performances in matters of sound quality and hearing comfort. They allow a proper adaptation while amplifying the sound according to the reached frequencies. The analog technology is also widely used: it is more ancient but less expensive. You can choose between these two technologies according to your needs in matters of amplification. The actual evolution of technologies is now promoting a large spreading of the digital technology, while the analog technology is used less frequently.
2. 2- Intra auricular esthetics: : This prosthesis is introduced inside the external auditory conduct, but it has to be manipulated with care and caution. The ears contour: they are more visible than the intra auricular device but are comfortable and easier to manipulate. A qualified audio-prosthesis professional will help guide your choice and adapt your prosthesis to your ear’s needs. The adaptation will be completed within a few weeks and 3 to 4 sessions at the audio-prosthesis professional. The patient will then need regular control visits: (after three, six and twelve months, and the twice a year…) to make sure that the auditory aid is functioning properly. The patient must react to the first signs of hearing discomfort, in order to be able to correct his audition promptly and obtain an optimum result.