The inability to perceive sounds. There are two major forms: (a) conductive deafness and (b) perceptive deafness.
The fact of being unable to hear in circumstances where most people would.
partial or complete loss of hearing in one or both ears, caused by the absence or incomplete development of the ear, the auditory nerve, or parts of the brain, by damage to the hearing apparatus (e.g., from infection or injury); or by degeneration (from aging) of the hearing apparatus. In assessing deafness, the degree of hearing loss, the types of sounds that can be discriminated, and the cause of the impairment generally classified as conductive hearing loss or sensorineural hearing loss are determined; treatment depends on these findings and may involve the use of a hearing aid.
An inability to hear, which may affect any age group, with consequences ranging from minor to severe. A small proportion of hearing-impaired persons in the United States are considered profoundly deaf, meaning their hearing loss is so severe they cannot benefit from hearing aids or other forms of mechanical sound amplification. A much larger proportion of people who are hearing impaired can benefit, in varying degrees, from the use of amplification devices.
Partial or total loss of hearing in one or both ears. Conductive deafness is due to a defect in the conduction of sound from the external ear to the internal ear, most commonly an infection affecting the small bones in the middle ear (otitis media) but also caused by an abnormal condition of the inner ear that affects the conduction of sound. Perceptive deafness (sensorineural deafness) is due to a lesion of the cochlea in the inner ear, the auditory nerve, or the auditory centers in the brain. It may be present from birth (for example if the mother was affected with German measles during pregnancy). In adults it may be brought on by injury, disease (e.g. Meniere’s disease), or prolonged exposure to loud noises; progressive perceptive deafness (presbycusis) is common with advancing age.
Impairment of hearing, which affects about 2 million adults in the UK. In infants, permanent deafness is much less common: about 1-2 per 1,000. It is essential, however, that deafness is picked up early so that appropriate treatment and support can be given to improve hearing and/or ensure that the child can learn to speak.
Complete or partial loss of the ability to hear. The deficit may be temporary or permanent. More than 20 million Americans have hearing impairment; most of them are older than 65, although about 5% are children. Hereditary forms of hearing impairment affect about 1 newborn out of 2000. In this population hearing deficits may impair language acquisition and speech. Acquired hearing loss affects the lives of nearly half of all people over 80, in whom it may be a prominent cause of social isolation or depression.
The total or partial absence of auditory perception in either one or both ears. Deafness can be categorized into two types: conductive deafness, resulting from impaired sound conduction from the outer to the inner ear; and sensorineural deafness, characterized by the inability to transmit sounds effectively to the brain.
The primary cause of conductive deafness among adults is frequently attributed to the accumulation of earwax. A less prevalent cause is otosclerosis, a condition that impairs the normal mobility of the stapes, a small bone located in the middle ear. In children, conductive deafness commonly arises from otitis media, an infection occurring in the middle ear, or glue ear, which involves the accumulation of viscous fluid in the middle ear. In rare instances, deafness can result from a ruptured eardrum.
Sensorineural deafness can manifest from birth, and it may stem from a birth-related injury or harm caused by maternal rubella infection during the early stages of pregnancy. Additionally, damage to the inner ear can occur shortly after birth as a consequence of severe neonatal jaundice.
During later stages of life, sensorineural deafness can be attributed to damage affecting the cochlea and/or labyrinth of the inner ear. This form of deafness may arise from prolonged exposure to loud noises, Ménière’s disease, specific medications, or certain viral infections. Additionally, the cochlea and labyrinth naturally deteriorate with advancing age, resulting in a condition known as presbycusis. Sensorineural deafness resulting from damage to the auditory nerve can be associated with an acoustic neuroma, which is a noncancerous tumor that develops along the nerve.
When a baby is born with congenital deafness, their ability to respond to sounds is impaired. While crying typically remains within the normal range, the baby does not engage in babbling or produce the usual vocalizations that contribute to speech development. In the case of an adult experiencing progressive hearing loss, the sounds they perceive not only become quieter than before but may also be distorted and less intelligible.
Deafness can be accompanied by the presence of tinnitus, which refers to the perception of noises in the ear, and vertigo, characterized by dizziness and a loss of balance. In some cases, deafness can contribute to feelings of confusion, while in other instances, it may lead to symptoms of depression.
Using an otoscope, a visual apparatus equipped with an attached light, the examination of the ear can determine whether the outer-ear canal is obstructed by earwax or if the eardrum is inflamed, perforated, or exhibiting fluid accumulation behind it.
Following a physical examination, hearing tests are often conducted to assess the nature of the deafness. These tests aid in determining whether the deafness is of a conductive or sensorineural origin.
The appropriate treatment for deafness depends on the underlying cause. In many cases of conductive deafness, the removal of excess earwax proves to be an effective remedy. Otosclerosis, on the other hand, is commonly addressed through a surgical procedure known as stapedectomy, which involves the replacement of the stapes bone with an artificial substitute. For the treatment of glue ear, a combination of surgery and the insertion of a grommet, a small tube that facilitates the drainage of fluid from the middle ear, may be employed.
Many children born with deafness have the capacity to acquire effective communication skills, often through the utilization of sign language. Profoundly deaf adults and children may find assistance through cochlear implants, which are implanted electrodes capable of receiving sound signals in the inner ear. However, it’s important to note that cochlear implants are not suitable for everyone. Individuals with sensorineural deafness typically rely on hearing aids to amplify the volume of sound reaching their inner ear. Lip-reading is a valuable skill for individuals who experience hearing difficulties, regardless of the type or severity of their deafness. Additional aids, such as amplifiers for telephone earpieces, are available to assist deaf individuals in carrying out everyday tasks.
The diminished capacity to hear, which encompasses varying levels of hearing loss.