Hearing loss
Partial or total inability to hear, affecting billions worldwide.
Hearing loss is a partial or total inability to hear, which may be present at birth or acquired later. It can affect one or both ears, be temporary or permanent, and ranges from minimal to profound severity. In children, hearing loss can impair spoken language acquisition; in adults, it can hinder social interaction and work. Age-related hearing loss typically affects both ears due to cochlear hair cell loss and may lead to isolation and loneliness, especially in older people.
- global prevalence
- Affects about 1.1 billion people to some degree
- childhood onset
- Began during childhood for 65 million
- preventable proportion
- About half of hearing loss globally is preventable through public health measures
Lore & Background
Hearing loss is diagnosed when a person cannot hear 25 decibels in at least one ear. It is categorized by severity: minimal/slight (15 to 25 dB), mild (25 to 40 dB), moderate (41 to 55 dB), moderate-severe (56 to 70 dB), severe (71 to 90 dB), and profound (greater than 90 dB). There are three main types: conductive, sensorineural, and mixed hearing loss. Causes include genetics, ageing, noise exposure, infections, birth complications, ear or brain trauma, certain medications or toxins, and chronic ear infections. Infections during pregnancy such as cytomegalovirus, syphilis, and rubella can also cause hearing loss in children.
Reader's Guide
Hearing loss has significant implications for individuals and society. It is associated with cognitive decline, including an increased risk of Alzheimer's disease and dementia, with the risk rising as hearing loss severity increases. Hearing loss is also linked to thalamocortical dysrhythmia, which may contribute to tinnitus and visual snow syndrome. Early identification and support are especially important for children. Interventions include hearing aids, sign language, cochlear implants, subtitles, and lip reading. However, access to hearing aids is limited in many parts of the world. In New Zealand, public funding schemes and subscription models aim to improve affordability. The World Health Organization recommends limiting exposure to loud sounds and personal audio player use to one hour per day. Many in the Deaf community view deafness as a cultural difference rather than a disability and may reject cochlear implants.
Did You Know?
- About half of hearing loss globally is preventable through immunization, proper pregnancy care, avoiding loud noise, and avoiding certain medications.
- Hearing loss is associated with an increased risk of Alzheimer's disease and dementia, but not with vascular dementia.
- In profound deafness, even the highest intensity sounds from an audiometer may not be detected; in total deafness, no sounds at all can be heard.
- The terms 'hearing impaired', 'deaf-mute', or 'deaf and dumb' are discouraged by many in the deaf community as offensive.
Frequently Asked Questions
What is Hearing loss?
Hearing loss is a partial or complete reduction in one's ability to perceive sound, which can be present from birth or develop later in life. It may involve a single ear or both, and its severity ranges from barely noticeable to total deafness.
What are Hearing loss's 'powers' (symptoms and effects)?
In children it can disrupt the natural acquisition of spoken language, while in adults it often erodes social connections and workplace performance. Age-related cases, driven by the gradual death of cochlear hair cells, frequently push older individuals toward isolation and loneliness.
How does Hearing loss's story end (prognosis)?
Some episodes are temporary and resolve with treatment or on their own, while others—particularly those tied to cochlear damage—become permanent. About half of all global hearing loss could be averted through preventive public-health measures, meaning many of these 'endings' are still within reach.
Why is Hearing loss important in the broader 'canon' (why does it matter)?
It touches every age group and socioeconomic tier, with 65 million cases beginning in childhood and a disproportionate burden falling on lower-income regions. Its ripple effects on communication, education, employment, and mental well-being make it one of the most consequential conditions in the overall health narrative.
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