AudiometerAn audiometer is a machine used for evaluating hearing acuity. They usually consist of an embedded hardware unit connected to a pair of headphones and a test subject feedback button, sometimes controlled by a standard PC. Such systems can also be used with bone vibrators, to test conductive hearing mechanisms. Audiometers are standard equipment at ENT (ear, nose, throat) clinics and in audiology centers. An alternative to hardware audiometers are software audiometers, which are available in many different configurations.
Labyrinthine fistulaA labyrinthine fistula is an abnormal opening in the inner ear. This can result in leakage of the perilymph into the middle ear. This includes specifically a perilymph fistula (PLF), an abnormal connection between the fluid of the inner ear and the air-filled middle ear. This is caused by a rupture of the round window or oval window ligaments separating the inner and middle ear. Another type of labyrinthine fistula is the superior semicircular canal dehiscence, which allows the inner ear to be influenced by the intracranial pressure directly.
Endolymphatic hydropsEndolymphatic hydrops is a disorder of the inner ear. It consists of an excessive build-up of the endolymph fluid, which fills the hearing and balance structures of the inner ear. Endolymph fluid, which is partly regulated by the endolymph sac, flows through the inner ear and is critical to the function of all sensory cells in the inner ear. In addition to water, endolymph fluid contains salts such as sodium, potassium, chloride and other electrolytes.
Hearing protection fit-testingHearing protector fit-testing, also known as field attenuation estimation system (FAES), measures the degree of noise attenuation when using the hearing protection device by a particular worker in the enterprise. Such measurements are necessary because noise attenuation is very variable among workers, and it can be close to zero for a significant proportion of them. Individual anatomical differences and varying ability to correctly apply HPD do not allow predicting noise attenuation in workers based on laboratory measurements with satisfactory accuracy.
Occupational hazardAn occupational hazard is a hazard experienced in the workplace. This encompasses many types of hazards, including chemical hazards, biological hazards (biohazards), psychosocial hazards, and physical hazards. In the United States, the National Institute for Occupational Safety and Health (NIOSH) conduct workplace investigations and research addressing workplace health and safety hazards resulting in guidelines. The Occupational Safety and Health Administration (OSHA) establishes enforceable standards to prevent workplace injuries and illnesses.
Safe listeningSafe listening is a framework for health promotion actions to ensure that sound-related recreational activities (such as concerts, nightclubs, and listening to music, broadcasts, or podcasts) do not pose a risk to hearing. While research shows that repeated exposures to any loud sounds can cause hearing disorders and other health effects, safe listening applies specifically to voluntary listening through personal listening systems, personal sound amplification products (PSAPs), or at entertainment venues and events.
Middle ear implantA middle ear implant is a hearing device that is surgically implanted into the middle ear. They help people with conductive, sensorineural or mixed hearing loss to hear. Middle ear implants work by improving the conduction of sound vibrations from the middle ear to the inner ear. There are two types of middle ear devices: active and passive. Active middle ear implants (AMEI) consist of an external audio processor and an internal implant, which actively vibrates the structures of the middle ear.
Usher syndromeUsher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes resulting in a combination of hearing loss and visual impairment. It is a major cause of deafblindness and is at present incurable. Usher syndrome is classed into three subtypes (I, II and III) according to the genes responsible and the onset of deafness.
OralismOralism is the education of deaf students through oral language by using lip reading, speech, and mimicking the mouth shapes and breathing patterns of speech. Oralism came into popular use in the United States around the late 1860s. In 1867, the Clarke School for the Deaf in Northampton, Massachusetts, was the first school to start teaching in this manner. Oralism and its contrast, manualism, manifest differently in deaf education and are a source of controversy for involved communities.
Otitis externaOtitis externa, also called swimmer's ear, is inflammation of the ear canal. It often presents with ear pain, swelling of the ear canal, and occasionally decreased hearing. Typically there is pain with movement of the outer ear. A high fever is typically not present except in severe cases. Otitis externa may be acute (lasting less than six weeks) or chronic (lasting more than three months). Acute cases are typically due to bacterial infection, and chronic cases are often due to allergies and autoimmune disorders.