Hearing aid loops (and how they work)
Governmental regulations dictate how services – including railways – offer accessible services to all kinds of citizens. At Televic GSP, we offer outstanding solutions that meet and exceed these regulations in order to provide optimal experiences to all train passengers by, for example, integrating a high-quality hearing aid loop system.
What are hearing aid loops?
In short, a hearing aid loop (HAL) is a wire loop installed within the core of a rail or tram car at head height that generates a magnetic field. This magnetic field is detected by telecoils – special components that are built standard into most hearing aid devices – and translated into sound. When HALs are connected to the rail car’s loudspeakers, they enable hard-of-hearing people to listen to broadcast messages via their in-ear hearing aids.
“Although there are no general requirements for their use in continental Europe, HALs are increasingly important for operators to be able to provide high quality services and experiences to every passenger,” asserts Kristof Boerjan, embedded passenger systems product manager at Televic GSP. “We are strongly investing in our modular TRACS audio platform, which ensures excellent audio experiences in a wide range of challenging conditions, and which integrates HAL technology. ”
Prioritizing high-quality audio
Properly installing a HAL to enable clear, noise-free audio broadcasting isn’t a simple task. Railway cars and trams are composed of materials that affect the magnetic field and can interfere with broadcast messages.
Kristof: “Because of this, it’s crucial to carefully consider how to incorporate the loop hardware into the car’s infrastructure to achieve the best possible result.
You can’t just throw a HAL anywhere in the car and expect it to work – it’s an embedded solution. When collaborating with our customers to develop and install a HAL solution, we always support them in the feasibility process as well as with audio simulation for specific use cases in order to guarantee a high-quality passenger experience.”
Not simply volume – but clarity and precision
Human speech is highly dynamic. “When we speak, our voices vary in pitch and volume, and these changes are very important in the way we perceive and understand messages,” Kristof continues. “In fact, the EU’s Technical Specifications for Interoperability for Persons with Reduced Mobility (TSI-PRM) specifies a minimum STI-PA value to be achieved for good intelligibility. With the TRACS platform, we enable our customers to surpass this requirement by offering a high STI value at maximum broadcast level.”
The TRACS platform of Televic GSP offers a set of state-of-the-art audio algorithms that enhance sound quality by, for example, reducing noise and equalizing frequency characteristics. These algorithms also improve the quality of the sound perceived by hearing aid users, as the quality of HAL input signal is also improved.
“Even more, we provide dedicated outputs to one or more hearing aid loop amplifiers instead of connecting to a single loudspeaker branch. The zoning concept of the TRACS platform is designed to broadcast different content in separate zones – first and second class, for example. By using dedicated output, we can also apply the zoning concept to the hearing aid loop system, or alternatively target different zones with one HAL.”