Partial or total inability to hear. In conduction deafness, the passage of sound vibrations through the ear is interrupted. The obstacle may be earwax, a ruptured eardrum, or stapes fixation, which prevents the stapes bone from transmitting sound vibrations to the inner ear. In sensorineural deafness, a defect in the sensory cells of the inner ear (e.g., injury by excessive noise) or in the vestibulocochlear or eighth cranial nerves prevents the transmission of sound impulses to the auditory centre in the brain. Some deaf people are helped by hearing aids or cochlear implants; others can learn to communicate with sign language and/or lip reading.
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Device that increases the loudness of sounds in the user's ear. Its principal components are a microphone, an amplifier, and an earphone. Hearing aids are increasingly smaller and less conspicuous, fitting behind the earlobe or within the ear canal. They have widely differing characteristics, amplifying different components of speech sounds for maximum comprehension by each wearer. Hearing aids with automatic volume control vary the amplification automatically with the input.
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In law, a trial, or more specifically the formal examination of a cause before a judge according to the laws of the land. In popular usage the term often refers to a formal proceeding before a magistrate prior to the inception of a case, and in particular to a preliminary hearing, where a magistrate or judge determines whether the evidence justifies proceeding with the case.
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