Infrared hearing aid

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An infrared hearing aid is a system with which sound signals or speech are made accessible in amplified form for people who are hard of hearing . The signal transmission between the device components takes place with infrared light and represents a form of optical sound transmission .

Basic principle

The device configuration consists of a transmitter and a receiver . The desired audio signals are recorded at the "transmitter", electronically converted into modulated infrared light and transmitted in the direction of the receiver. The person with hearing impairments in turn carries the receiver, which converts the infrared light using sound technology back into sound waves , which are then guided into the ear using suitable means . There is actually no " amplification " of the sound, only the attenuation of the sound due to the spatial distance from the sound source is bypassed by the transmission process.

Version for radio or television sound

An additional transmitter on the radio or television set transmits the audio signals via infrared light. Due to its shape, the receiver is often called the “under-the-chin receiver”. It has two ear pieces with mini speakers on each short plastic tube. The lower ends of these tubes are connected by a more or less rod-shaped "bracket" housing that is worn below the chin. The electronics, which convert the received infrared light back into sound waves, are located in the bracket housing.

There are also differently shaped receiver parts that are not connected directly to the ear, but to the existing hearing aid .

Features of use

The volume can be adjusted individually independently of the volume of the radio or television set. Several persons equipped with receivers can hear at different volumes within the infrared light range without influencing each other. The inserted ear pieces also dampen annoying background noises to a certain extent .

In principle, freedom of movement is possible in the immediate vicinity of the infrared transmitter, but reception may be impaired if the transmitter is covered by objects or people (" shadows ") or at a greater distance.

Problems can also arise in bright sunshine, as the sunlight spectrum also has infrared components.

These devices are used not only in private living areas, but also in concert halls , adult education centers , churches and daycare centers for the elderly .

See also

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