Assistive devices or Assistive technology are used by the hearing loss or language disorder people to communicate. These devices help a person to hear and understand what is being said more clearly or to express thoughts more easily. With the development of digital and wireless technologies, many of the devices are becoming available for the hearing loss people. By using these devices they can communicate easily and participate in their daily life activities.
Types of Assistive Devices are given below:-
1. Assistive Listening Devices
2. Augmentative and alternative communication
3. Alerting Devices
Assistive Listening Devices:-
Assistive Listening Device amplifies the sounds that you want to hear. This sound is especially amplified where there is a lot of background noise. This device can be used with a hearing aid or cochlear implant to help a wearer hear certain sounds better.
Types of Assistive Listening Devices:-
There are many types of ALDs which are available to improve the sound transmission for hearing impairment people. Some of them are designed for the large facilities like a classroom, theaters, places of worship and airports. Some other types of ALDs are intended for the personal use in small settings and for one-on-one conversations. All types of devices are used with or without hearing aids or cochlear implant. For large facilities, ALD systems contain hearing loop systems, frequency-modulated systems and infrared systems.
1. Hearing Loop Systems:- These systems are also known as the induction loop systems. To transmit the sound, electromagnetic energy is used in these systems. This system contains four parts:
v A sound source, like a public address system, microphone, or home TV or telephone.
v An amplifier
v A thin loop of wire which encircles a room or branches out beneath carpeting.
v A receiver worn as a headset or within the ears.
Amplified sound travels by the loop and creates an electromagnetic field. This field is picked up directly by a hearing loop receiver or a telecoil. Hearing loop receiver is a miniature wireless receiver that is built into many hearing aids and cochlear implants.
2. FM Systems:- These systems use radio signals to transmit the amplified sounds. They are often used in classrooms, where the instructor wears small microphone connected to a transmitter and the student wears the receiver, which is tuned to a specific frequency, or channel. People who have a telecoil in their hearing machine or cochlear implant may also wear a wire around their neck or behind their aid or implant. This wire converts a signal into magnetic signals that can be picked up by the telecoil directly.
3. Infrared Systems:- These devices use infrared light to transmit sound. A transmitter is used to convert sound into a light signal. After converting the sound into a light signal, transmitter beams it to the receiver that is worn by a listener. After decoding by the receiver, the infrared signal converted back to sound.
4. Personal amplifiers:- These systems are helpful in places in which the above systems are unavailable or watching TV, being outdoors, or travelling in a car. These devices reduce the background noise and increase the sound level. Some of the devices have directional microphones.