A. Hearing system
The auditory system consists of the outer ear, the middle ear, the inner ear, the auditory nerves and the brain. The outer ear consists of the auricle and the external auditory canal. The middle ear is an air-filled cavity containing the eardrum, three ossicles, and the Eustachian tube (which balances the air pressure in the middle and outer ears). The inner ear is divided into three parts: the cochlea, the semicircular canals (which help the body maintain balance) and the inner auditory nerves. The cochlea and the semicircular canals are filled with fluid and lined with a layer of hair cells.
The auricle is responsible for collecting sound and recognizing the direction of sound, which travels through the ear canal to the middle ear. When the sound reaches the eardrum, it is transformed into a mechanical vibration. Then, the three ossicles in the middle ear increase the amplitude of the vibration and send it to the inner ear. The fluid in the cochlea is stimulated by the vibration and stimulates the hair cells, generating a signal that is sent to the brain via the inner ear hearing nerve. After filtering, synthesizing and analyzing, the message is understood.
B. Weak hearing
Hearing loss can be caused by problems in any part of the auditory system. Hearing loss can be congenital or acquired. Congenital hearing loss occurs at birth, while acquired hearing loss occurs after birth.
There are three types of hearing loss: conductive hearing loss, sensorineural hearing loss and mixed hearing loss.
I. Conductive hearing loss
Conductive hearing loss is caused by damage or obstruction of the outer or middle ear, resulting in a decrease in the volume of the transmission, resulting in conductive hearing loss. The degree of hearing loss varies depending on the cause, but tends to be no more than moderate to severe. Some of the causes include.
- Congenital problems - e.g. congenital dysplasia, oxygen deprivation at birth, severe yellow bile and head impact at birth
- Foreign objects or earwax blocking the ear canal
- Inflammation of the external auditory canal
- Otitis media - often in children
- Loss of eardrum - can be caused by otitis media or a blow to the head.
- Ossicular Sclerosis - Genetic
Some forms of hearing loss can be treated with medication or surgery. If medication or surgery is not suitable, hearing aids or hearing assistive devices may be tried.
II. Sensorineural Hypoacusis
Sensorineural hearing loss is caused by damage to the cochlea (sensorineural) or auditory nerves (neural). A decrease in the volume of a transmission is considered to be sensorineural hearing loss, while a muffled transmission is considered to be neurological hearing loss. There are different causes of hearing loss. These include:
- natural aging
- Prolonged exposure to noise
- Bacterial infections - e.g. meningitis
- Viral infections - e.g. mumps, measles
- Congenital problems - e.g. congenital dysplasia, oxygen deprivation at birth, severe yellow bile and head impact at birth
- Taking drugs that damage the hearing system
- Head damage
- Auditory Nerve Tumor
Individuals with sensorineural hearing loss may be prescribed hearing aids or hearing assistive devices.
III. Mixed weak hearing
Mixed amblyopia is defined as conductive amblyopia mixed with sensorineural amblyopia .
If you suspect that you are suffering from hearing loss, you should undergo a hearing test or see a doctor as soon as possible to avoid delaying the onset of the disease that may cause hearing loss and depression due to prolonged hearing loss.
If you suspect that you are suffering from hearing loss, you should undergo a hearing test or see a doctor as soon as possible to avoid delaying the onset of the disease that may cause hearing loss and depression due to prolonged hearing loss.
The degree of hearing loss can be categorized as follows.
| Light | 26 – 40 dB |
| Moderate | 41 – 50 dB |
| Severe | 51 – 70 dB |
| Critical | 71 – 90 dB |
| Depths | 91 dB or more |
