Large Area Listening Systems. Large area listening systems are the most popular of all hearing enhancement devices, and are used in theaters, movie houses, auditoriums and houses of worship. There are three basic types: FM radio, infra-red (IR) light and a looped wire around the room, called an induction loop.
The strings are called Phloem Bundles (pronounced flom). They are part of the system that carries nutrition to all parts of the banana.
For ânylonâ strings, manufacturers typically use polymers comprised of amide functional groups such as aliphatic polyamides (including Nylon 6 and Nylon 66), and polymers comprised of ketone functional groups such as Zyex (AKA polyetheretherketone, or PEEK).