A person is considered to be deaf if they cannot hear the same range of sounds as a person with normal hearing ability. People that cannot hear any sounds are also deaf. People who are partially deaf may hear some sounds and may hear words.
People who cannot hear and understand words well are hard of hearing.
Things that help deaf people
- Hearing aid, which helps a deaf person to hear sounds.
- Teletypewriter (TTY), that allows a deaf person to communicate with people.
- Sign language, which allows a deaf person to have a conversation with someone else.
- Hearing dog is a dog that has been trained to hear sounds and help a deaf person.
Treatment depends on the specific cause if known as well as the extent, type and configuration of the hearing loss. Most hearing loss, that resulting from age and noise, is progressive and irreversible, and there are currently no approved or recommended treatments; management is by hearing aid. A few specific kinds of hearing loss are amenable to surgical treatment. In other cases, treatment is addressed to underlying pathologies, but any hearing loss incurred may be permanent.
There are a number of devices that can improve hearing in those who are deaf or hard of hearing or allow people with these conditions to manage better in their lives.
Hearing aids are devices that work to improve the hearing and speech comprehension of those with hearing loss. It works by magnifying the sound vibrations in the ear so that one can understand what is being said around them. The use of this technological device may or may not have an effect on one's sociability. Some people feel as if they cannot live without one because they say it is the only thing that keeps them engaged with the public. Conversely, there are many people who choose not to wear their hearing aids for a multitude of reasons. The vast majority of these reasons stem from either poor performance of the aid, in which the user notices more amplification of background noises instead of the sounds they intended, or from issues with comfort, care, or maintenance of the device; financial factors have also been reported. A comparatively small fraction of people choose not to wear hearing aids due to aesthetic concerns and/or stigma around wearing the device.
Many deaf and hard of hearing individuals use assistive devices in their daily lives:
- Individuals can communicate by telephone using telephone typewriters (TTY). Other common names are textphone, minicom and telecommunications device for the deaf (TDD). These devices look like typewriters or word processors and transmit typed text over regular telephone lines. This allows communication through visual messaging. TTYs can transmit messages to individuals who don’t have TTY by using the National Relay service which is an operator that acts as a messenger to each caller. For mobile phones, software apps are available to provide TDD/textphone functionality on some carriers/models to provide 2-way communications.
- There are several new telecommunications relay service technologies including IP Relay and captioned telephone technologies. A deaf or hard of hearing person can communicate over the phone with a hearing person via a human translator. Phone captioning is a service in which a hearing person's speech is captioned by a third party, enabling a deaf or hard of hearing person to conduct a conversation with a hearing person over the phone. Wireless, Internet and mobile phone/SMS text messaging are beginning to take over the role of the TDD.
- Real-time text technologies, involving streaming text that is continuously transmitted as it is typed or otherwise composed. This allows conversational use of text. Software programs are now available that automatically generate a closed-captioning of conversations. Examples include discussions in conference rooms, teleconference calls, classroom lectures, and/or religious services.
- Instant messaging software.
- Videophones and similar video technologies can be used for distance communication using sign language. Video conferencing technologies permit signed conversations as well as permitting a sign language–English interpreter to voice and sign conversations between a deaf or hard of hearing person and that person's hearing party, negating the use of a TTY device or computer keyboard.
- Video relay service and video remote interpreting (VRI) services also use a third-party telecommunication service to allow a deaf or hard-of-hearing person to communicate quickly and conveniently with a hearing person, through a sign language interpreter.
- Hearing dogs are a specific type of assistance dog specifically selected and trained to assist the deaf and hard of hearing by alerting their handler to important sounds, such as doorbells, smoke alarms, ringing telephones, or alarm clocks.
- The advent of the Internet's World Wide Web and closed captioning has given the deaf and hard of hearing unprecedented access to information. Electronic mail and online chat have reduced the need for deaf and hard-of-hearing people to use a third-party Telecommunications Relay Service to communicate with the hearing and other deaf people.
- A person with hearing loss cannot always hear the phone or distinguish their own ringtone from another. A signalling transmitter can be attached to a phone that will cause a light or a vibration device to activate. Transmitters can also be used to activate visuals cues to represent fire alarms.
- Individuals with hearing loss require phones with amplifiers that have a higher power of amplification when compared to a regular phone. The Hearing Aid Telephone Interconnect System is a hands free amplification system which allows people to amplify sound when using telephones, cell phones, computer and pay phones by way of the attachment of a portable unit.
Wireless hearing aids
A wireless device has two main components: a transmitter and a receiver. The transmitter broadcasts the captured sound, and the receiver detects the broadcast audio and enables the incoming audio stream to be connected to accommodations such as hearing aids or captioning systems.
Three types of wireless systems are commonly used: FM, audio induction loop, and InfraRed. Each system has advantages and benefits for particular uses. FM systems can be battery operated or plugged into an electrical outlet. FM system produce an analog audio signal, meaning they have extremely high fidelity. Many FM systems are very small in size, allowing them to be used in mobile situations. The audio induction loop permits the listener with hearing loss to be free of wearing a receiver provided that the listener has a hearing aid or cochlear implant processor with an accessory called a "telecoil". If the listener does not have a telecoil, then he or she must carry a receiver with an earpiece. As with FM systems, the infrared (IR) system also requires a receiver to be worn or carried by the listener. An advantage of IR wireless systems is that people in adjoining rooms cannot listen in on conversations, making it useful for situations where privacy and confidentiality are required. Another way to achieve confidentiality is to use a hardwired amplifier, which contains or is connected to a microphone and transmits no signal beyond the earpiece plugged directly into it.
There is no treatment surgical or otherwise for hearing lost due to the most common causes (age, noise and genetic defects). For a few specific conditions, surgical intervention can provide a remedy:
- surgical correction of superior canal dehiscence
- myringotomy, surgical insertion of drainage ventilation tubes in the tympanic membrane. Such placement is usually temporary until the underlying pathology (infection or other inflammation) can be resolved.
- radiotherapy or surgical excision of vestibular schwannoma or acoustic neuroma, though, in most cases, it is unlikely that hearing will be preserved
- Stapedectomy and stapedotomy for otosclerosis - replacement or reshaping of the stapes bone of the middle ear can restore hearing in cases of conductive hearing loss
Surgical and implantable hearing aids are an alternative to conventional external hearing aids. If the ear is dry and not infected, an air conduction aid could be tried; if the ear is draining, a direct bone condition hearing aid is often the best solution. If the conductive part of the hearing loss is more than 30–35 dB, an air conduction device could have problems overcoming this gap. A bone-anchored hearing aid could, in this situation, be a good option. The active bone conduction hearing implant Bonebridge is also an option. This implant is invisible under the intact skin and therefore minimises the risk of skin irritations.
Cochlear implants improve outcomes in people with hearing loss in either one or both ears. They work by artificial stimulation of the cochlear nerve by providing an electric impulse substitution for the firing of hair cells. They are expensive, and require programming along with extensive training for effectiveness.
Cochlear implants as well as bone conduction implants can help with single sided deafness. Middle ear implants or bone conduction implants can help with conductive hearing loss.
People with cochlear implants are at a higher risk for bacterial meningitis. Thus, meningitis vaccination is recommended. People who have hearing loss, especially those who develop a hearing problem in childhood or old age, may need support and technical adaptations as part of the rehabilitation process. Recent research shows variations in efficacy but some studies show that if implanted at a very young age, some profoundly impaired children can acquire effective hearing and speech, particularly if supported by appropriate rehabilitation.
For a classroom setting, children with hearing loss often benefit from direct instruction and communication. One option for students is to attend a school for the Deaf, where they will have access to the language, communication, and education. Another option is to have the child attend a mainstream program, with special accommodation such as providing favorable seating for the child. Having the student sit as close to the teacher as possible improves the student's ability to hear the teacher's voice and to more easily read the teacher's lips. When lecturing, teachers can help the student by facing them and by limiting unnecessary noise in the classroom. In particular, the teacher can avoid talking when their back is turned to the classroom, such as while writing on a whiteboard.
Some other approaches for classroom accommodations include pairing deaf or hard of hearing students with hearing students. This allows the deaf or hard of hearing student to ask the hearing student questions about concepts that they have not understood. The use of CART (Communication Access Real Time) systems, where an individual types a captioning of what the teacher is saying, is also beneficial. The student views this captioning on their computer. Automated captioning systems are also becoming a popular option. In an automated system, software, instead of a person, is used to generate the captioning. Unlike CART systems, automated systems generally do not require an Internet connection and thus they can be used anywhere and anytime. Another advantage of automated systems over CART is that they are much lower in cost. However, automated systems are generally designed to only transcribe what the teacher is saying and to not transcribe what other students say. An automated system works best for situations where just the teacher is speaking, whereas a CART system will be preferred for situations where there is a lot of classroom discussion.
For those students who are completely deaf, one of the most common interventions is having the child communicate with others through an interpreter using sign language.
There are different causes of deafness:
- Age: Many people will lose their hearing as they get older.
- Exposure to noise: Being in a noisy environment for a long time may damage ears and cause hearing loss.
- Genetic conditions: There can be a family history of deafness. If the mother and/or father are deaf, their child will have a strong chance of being deaf.
- Diseases: Certain diseases may cause deafness.
- Drugs: Certain drugs may affect hearing.
- Chemicals: Certain chemicals can damage the ear.
- Natural: People are just born that way. Sometimes there is no explanation why they are deaf.
Categories of deafness
Generally, there are two views of deafness:
- Medical view: the effects of deafness and measuring type and how much of loss (as seen in categories below).
- Cultural view: includes people who use sign language to communicate and are part of group of people who share life experiences. Referring to people of the cultural group the phrase "Deaf people" is used and deaf is capitalized (as shown previously). A person using the medical view would write "people who are deaf".
These categories may overlap.
- Unilateral – loss of hearing in one ear only
- Pre-lingual – deafness at birth or deafness that started before language is learned
- Peri-lingual – deafness that started while learning a first language
- Post-lingual – deafness that started after a language has been learned
- Partial – limited hearing loss
- Progressive – hearing loss that becomes worse as time passes
- Profound – complete or near-complete hearing loss
- Tone deaf – not able to hear differences in relative pitch (in music)
- Tinnitus – hearing damage that causes high pitched ringing. This makes it so that the person cannot hear other sounds
- Conductive – hearing loss caused by sound being blocked from going into ears
- Sensorineural – hearing loss caused by hair cells in ears being damaged
Alexander Graham Bell with teachers and students of the Scott Circle School for deaf children, Washington, D.C., 1883
Deafness Facts for Kids. Kiddle Encyclopedia.