What is an assistive listening device? It is a device used to assist people hear better in different situations. For instance, an assistive listening device may be used to aid someone to better hear a speech delivered through a Public Address system or even to hear the sound from a television better. An audio transmitter is used to isolate the required sound from any noise in the surrounding area and then relays the sound usually (through a wireless radio frequency) to a small receiver in the listener’s possession.
The receiver then finally transmits the sound to the listener’s ear through either a looped cord or direct audio input. An assistive listening is not a hearing aid although it can be used in conjunction with one. The goal is to reduce the strain that one would otherwise experience when listening to someone either from a distance or in an environment where there are other competing sounds.
There are different types of assistive listening device that one can choose from. PFM (Personal Frequency Modulation) systems have start similarities to a small radios and operate on specific transmission frequencies. The frequencies in the US for instance are assigned by the regulator, the Federeal Communications Commission.
PFMs are particularly useful when one is trying to listen to a book reading, a lecture, religious meetings or any gathering held in a public place such as a park. In more sophisticated PFM setups, the transmitter is actually setup as part and parcel of the sound system. In such settings, each person is then assigned a receiver.
A second type of assistive listening device are infrared enabled. These are usually used in smaller enclosed spaces such as the home (to listen to television or home video sound). However, it can be used in the outdoors like the PFM. The infrared assistive listening device also allows you to alter the volume to the level that best suits you.
Then there is the Induction Loop System which are more commonly used in large group settings. Government buildings and hospitals are two places you are likely to encounter the ILS assistive devices. This system works using a wire which is permanently installed (often under the floor).
It is then connected to a microphone through a speaker. When you speak into the microphone, an electromagnetic field is created in that room. If you then turn the receiver to the setting ‘T’, you will pick up the signal and can then alter the volume through to your satisfaction.
Finally, there is the one-to-one assistive listening device. As the name suggests, these are used when you want to hear one person specifically such as when someone is delivering a speech at a convention. The method of operation is simple: the person speaking is given a microphone and as they speak, the sound is amplified and sent straight to your receiver.
Each type of device has its merit and one must assess it against the event or occasion it is meant to be used in before finally making your decision.