Assistive Devices

Assistive Listening Devices (ALDs) are instrument designed for the purpose of making speech louder than noise or just helping people hear better.

  • Assistive Listening Devices can be used for:
    • Interactive Communication (such as face-to-face conversation, telephone conversation, meetings, etc)
    • Non-Interactive Communication (such as with TV/radio, movies, public events, etc).
    • Warning Signals (such as smoke alarms)
  • Examples of Assistive Listening Devices:
    • Personal or Group Amplifiers
      • A pocket talker, for example, is a personal listening system that useful with one on- one/small group communication/TV, and includes an amplifier, microphone, and earphone.
    • TV Listeners
      • Amplifying headphones or devices that plug into the TV allowing the user to adjust the volume or tone of the sound. Some will even connect to hearing aids!
    • Telephone Amplifiers
      • Designed to increase the volume or tone of the telephone receiver/speaker. A Telephone Pad can also be attached to the telephone receiver, allowing closer placement of the telephone receiver to the ear or Hearing Aid without feedback.
    • Closed Captioning
      • Television Closed Captioned allow the user to understand the audio portion by reading the subtitles on the TV screen
      • Telephone Closed Captioned (CapTel and Telecommunication Device for the Deaf TDD or TTY) allow the user to understand the the talker by reading the subtitles on a computer, telephone screen or other device
    • Signaling Devices
      • Devices that flash lights or use vibration units to alert the person (ie doorbell, telephone, fire, etc)
    • FM systems
      • Personal FM: This is a personal wireless system coupled to headphones and used with or without a HA.Hard-wire Systems: consist of a direct connection from a microphone to an amplifier and finally to a receiver (such as direct audio input/HA or earphone)
        • A remote microphone is worn by the speaker (such as a teacher), and sends signal via FM to a receiver worn by the listener (such as a student).
        • Microphone is called a transmitter, the FM unit itself is called a receiver
      • ALD Infrared: An ALD consisting of a microphone placed near the sound source of interest (such as TV) that broadcast over infrared light waves to a receiver, thus improving the signal-to-noise ratio.  This is also a personal wireless system coupled to headphones and used without or with a hearing aid (Direct Auditory Input with BTE)
      • Sound Field Amplification: An amplification of a classroom or other open area with a public address system/speakers, to improve signal-to-noise ratio (such as teacher voice over room noise) for all listeners.
        • Can be used, for example, with students/children having Auditory Attention Deficits, Central Auditory Processing Disorder, or fluctuating Hearing Loss.


      NOTE: Hardwire, induction loop, infrared, and FM systems can be used in conjunction with television. Induction Loops are a continuous wire surrounding a room that conducts electrical energy from an amplifier, thus creating a magnetic field.  A microphone is placed near the sound source, and the current flow from the loop is induced in the HA telecoil. The advantage of induction loops is that a cord is not required between the sound source and listener. One disadvantage may be their limited portability.



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