Deaf and Deafness Guide

Deaf and Deafness / Hearing Loss

Hearing loss refers to a diminished ability to hear sounds like other people do, while deafness refers to the inability to understand speech through hearing even when sound is amplified.

Profound deafness means the person cannot hear anything at all; they are unable to detect sound, even at the highest volume possible.

Hearing impairment, deafness, or hearing loss refers to the inability to hear things, either totally or partially.
A person who is not able to hear as well as someone with normal hearing – hearing thresholds of 25 dB or better in both ears – is said to have hearing loss. Hearing loss may be mild, moderate, severe or profound. It can affect one ear or both ears, and leads to difficulty in hearing conversational speech or loud sounds.

‘Hard of hearing’ refers to people with hearing loss ranging from mild to severe. They usually communicate through spoken language and can benefit from hearing aids, cochlear implants and other assistive devices as well as captioning. People with more significant hearing losses may benefit from cochlear implants.

‘Deaf’ people mostly have profound hearing loss, which implies very little or no hearing. They often use sign language for communication.

Some of the more common causes of hearing impairment are:
• Genetic conditions
• Infection during pregnancy, including cytomegalovirus, rubella, syphilis, herpes and toxoplasmosis
• Birth complications
• Craniofacial abnormalities
• Meningitis
• Head trauma or perforation of the eardrum
• Persistent ear infections (otitis media)
• Some syndromes and degenerative disorders


Learning to listen and speak, let alone understanding others, is usually much harder for someone who has hearing loss, especially from birth, or a very young age.

Hearing ability may be viewed on the continuum extending from perfect hearing on the one end to total inability to perceive any sound at the other. Most of us fall somewhere between these two extremes.

Socially, people tend to group themselves as being part of the "hearing world" or the "deaf world." In a few cases, individuals can move between these two "worlds."

In summary, deafness may be only a physical characteristic or it can signify both a physical condition with a social/cultural perspective. Hearing impairment can run the full gamut from mild loss to profound. The main characteristic that separates the hearing impaired person from the deaf person, is whether they relate primarily to the hearing world or to the deaf world.

There are many causes of hearing loss, some of which are genetic and others are due to external factors such as accident or prolonged exposure to loud noises. Hearing loss affects people of all ages.

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