Deafness has varying definitions in cultural and medical contexts. In medical contexts, the meaning of deafness ishearing loss that precludes a person from understanding spoken language, anaudiological condition.[1] In this context it is written with a lower cased. It later came to be used in a cultural context to refer to those who primarily communicate with adeafness aid or throughsign language regardless ofhearing ability, often capitalized asDeaf and referred to as "big D Deaf" in speech and sign.[2][3] The two definitions overlap but are not identical, as hearing loss includes cases that are not severe enough to impact spoken language comprehension, while cultural Deafness includes hearing people who use sign language, such aschildren of deaf adults.
The International Symbol for Deafness is used to identify facilities with hearing augmentation services, especiallyassistive listening devices.[4]
In a medical context, deafness is defined as a degree of hearing difference such that a person is unable to understand speech, even in the presence of amplification.[1] In profound deafness, even the loudest sounds produced by anaudiometer (an instrument used to measure hearing by producing pure tone sounds through a range of frequencies) may not be perceived by the person. In total deafness, no sounds at all, regardless of amplification or method of production, can be heard.
Neurologically, language is processed in the same areas of the brain whether one is deaf or hearing. The left hemisphere of the brain processes linguistic patterns whether by signed languages or by spoken languages.[5]
Deafness can be broken down into four different types of hearing loss:
All of these forms of hearing loss impair a person's hearing so they are not able to perceive or interpret sounds correctly. These different types of hearing loss occur in different parts of the ear, which make it difficult for the information being heard to get sent to the brain properly.
Hearing aids help people who struggle to understand normal conversations.
For each of these types, there are four different levels or amounts of hearing loss. The first level ismild hearing loss. This is when someone is still able to hear noises, but it is more difficult to hear the softer sounds. The second level ismoderate hearing loss, and this is when someone can hear almost nothing when someone is talking to them at a normal volume. The next level is severe hearing loss.Severe hearing loss is when someone can not hear any sounds when they are being produced at a normal level, and they can only hear minimal sounds that are being produced at a loud level. The final level isprofound hearing loss, which is when someone is not able to hear any sounds except for very loud ones.[6]
Millions of people globally live with deafness or hearing impairments. The 2005Survey of Income and Program Participation (SIPP) indicated that fewer than 1 in 20 Americans are deaf or hard of hearing at a level that makes normal conversations difficult to hear; more than half of these people are overretirement age.[7]
This fire alarm uses a flashing red light to alert people who cannot hear.
Several solutions are available for many people with hearing impairments.Hearing aids are a common device. Additionally, people may use devices that use blinking lights instead of noises for alarm clocks or other notifications.
Cochlear implants can be chosen at any age, including in babies.
Cochlear implants are an option for children and adults with severe or profound hearing loss. Cochlear implants are surgically placed devices that stimulate the cochlear nerve in order to help the person hear. A cochlear implant is used instead ofhearing aids in order to help when someone has difficulties understanding speech.[8] For children, the younger they are at the time of implantation, the better their auditory skill and perception.[9] Babies with confirmed bilateral profound sensorineural hearing loss may begin the surgical evaluation process for implantation as early as six months, with the US officially allowing the surgery to take place as early as nine months of age.[9] Children with other medical problems or other types of hearing loss may be considered at a slightly older age.[9] Parents sometimes have difficulty deciding to get cochlear implants for their child. Many felt a sense of urgency, and, in the end, most parents felt it was beneficial for their child.[10]
In a cultural context,Deaf culture refers to a tight-knitcultural group of people whoseprimary language issigned, and who practice social and cultural norms which are distinct from those of the surrounding hearing community. This community does not automatically include all those who are clinically or legally deaf, nor does it exclude every hearing person. According to Baker and Padden, it includes any person who "identifies him/herself as a member of the Deaf community, and other members accept that person as a part of the community",[11] an example beingchildren of deaf adults with normal hearing ability. It includes the set of social beliefs, behaviors, art, literary traditions, history, values, and shared institutions of communities that are influenced by deafness and which usesign languages as the main means of communication.[2][3] While deafness is often included within the umbrella ofdisability, members of the Deaf community tend to view deafness as a difference in human experience or itself as a language minority.[12][13]
Many non-disabled people continue to assume that deaf people have no autonomy and fail to provide people with support beyond hearing aids, which is something that must be addressed. Different non-governmental organizations around the world have created programs towards closing the gap between deaf and non-disabled people in developing countries. As children, deaf people learn literacy differently than hearing children. They learn to speak and write, whereas hearing children naturally learn to speak and eventually learn to write later on.[14] The Quota International organization with headquarters in the United States provided immense educational support in the Philippines, where it started providing free education to deaf children in the Leganes Resource Center for the Deaf. The Sounds Seekers British organization also provided support by offering audiology maintenance technology, to better assist those who are deaf in hard-to-reach places. The Nippon Foundation also supports deaf students at Gallaudet University and the National Technical Institute for the Deaf, through sponsoring international scholarships programs to encourage students to become future leaders in the deaf community. The more aid these organizations give to the deaf people, the more opportunities and resources disabled people must speak up about their struggles and goals that they aim to achieve. When more people understand how to leverage their privilege for the marginalized groups in the community, then we can build a more inclusive and tolerant environment for the generations that are yet to come.[2][3]
The first known record ofsign language in history comes fromPlato'sCratylus, written in the fifth century BCE. In a dialogue on the "correctness of names",Socrates says, "Suppose that we had no voice or tongue, and wanted to communicate with one another, should we not, like the deaf and dumb, make signs with the hands and head and the rest of the body?"[15] His belief that deaf people possessed an innate intelligence for language put him at odds with his studentAristotle, who said, "Those who are born deaf all become senseless and incapable of reason", and that "it is impossible to reason without the ability to hear".
This pronouncement would reverberate through the ages and it was not until the 17th century when manual alphabets began to emerge, as did various treatises ondeaf education, such asReducción de las letras y arte para enseñar a hablar a los mudos ('Reduction of letters and art for teaching mute people to speak'), written byJuan Pablo Bonet in Madrid in 1620, andDidascalocophus, or, The deaf and dumb mans tutor, written byGeorge Dalgarno in 1680.
In 1760, French philanthropic educatorCharles-Michel de l'Épée opened theworld's first free school for the deaf. The school won approval for government funding in 1791 and became known as the "Institution Nationale des Sourds-Muets à Paris".[16] The school inspired the opening of what is today known as theAmerican School for the Deaf, the oldest permanent school for the deaf in the United States, and indirectly,Gallaudet University, the world's first school for the advanced education of the deaf and hard of hearing, and to date, the only higher education institution in which all programs and services are specifically designed to accommodate deaf and hard of hearing students.
Parents of deaf and hard-of-hearing children often encounter difficulties when choosing an educational setting for their child. They may consider the needs and abilities of the child, how the school can make accommodations for the child, and the school environment itself.[17] Both the child and the parent may benefit from trial and error with different schools, to identify the best available environment.
