FM Systems

AV booth showing equipment and FM transmitter attached
FM transmitter hooked up to the AV equipment in the back of a large conference room
A national Park Service small group tour with a ranger and 4 people circled around him, all wearing a FM receiver and ear loops
A National Park Service small group tour with a ranger and 4 people circled around him, all wearing a FM receiver and ear loops

FM Systems, or Radio Frequency Assistive Listening Systems, transmit wireless, low power FM frequency radio transmission from a sound system to FM receivers.

Please also see

Loaned Equipment

All users need to borrow a receiver from the site/facility and

  1. If the person doesn’t have hearing aids or hearing aids without a telecoil – Headphones or earbuds
  2. If the person has hearing aids with a telecoil – A neckloop

See “how to use” for a video and more information.

Neckloops

Neckloops must be compatible with receivers and preferably ordered from the same manufacturer that makes the receiver. If neckloops are ordered retroactively – or of a different make as the receiver, there may be a mismatch causing the neckloops to be underpowered and thus not provide a strong enough magnetic signal for the telecoil to pick up, and when the user increases the volume setting on the receiver, it can cause distortion.

FM Systems: Advantages and Disadvantages

  • Ability to hear more clearly in indoor and outdoor settings
  • Ability to hear more clearly during tours, outdoors or indoors
  • Users lose dignity by “outing” their disability
  • Users have inconveniences of borrowing and returning equipment
  • Users can experience borrowed equipment failure
  • Neckloops sometime have a weak signal
  • Users may not use the system, for reasons above. 
  • If users can’t understand how to use the system or the availability of the system, they may choose to stay home
  • Relatively simple installation
  • Flexible listening locations
  • Can be used outdoors
  • Has a range of approximately 500 feet / 153 meters
  • Some systems offer secured signal
  • Multi-channel audio available
  • Can conflict with other RF devices in narrow license free frequency bands
  • Borrowed receivers required for all users
  • Receivers require battery replacement or recharging after use
  • Facility owner time required to provide, explain, retrieve, and maintain receivers (hygiene concerns)
  • EMI interference. Using a neckloop requires the users to use telecoils – and it’s the telecoil that can pick up EMI interference in a building. The interference is heard as buzzing by a user as soon as they turn the telecoil on. The buzz is heard whether or not an FM system is installed. That is because the EMI interference is in the building and is usually caused by poorly installed electrical wiring. Remediating the EMI interference may require the services of an electrician.
  • Frequency range can vary in different locations
  • Some systems require license for FM/radio
  • Privacy concerns if not encrypted

Resources