Happy New Year 2022!
Wishing you and yours a very Happy New Year for 2022! Please stay safe
Hearing Loop On BART in Testing Phase Thanks To HLAA-DV
Hello Lamorinda, Walnut Creek and friends beyond!
BART is testing out a hearing loop for hearing impaired people, so that announcements in Bart stations can be heard more clearly. Thanks to the efforts of the Diablo Valley Chapter of the Hearing Loss Association of America (HLAA-DV), testing has begun at the Fremont station. The goal is to eventually loop the entire Bart system, both on the platforms where there can be a lot of noise in the form of wind, traffic and trains. The station attendant's speaker will also be looped and new Bart cars will be looped so that announcements can be audible.
What is a loop anyway and why is it needed?
To understand the need, we have to first take a step back. People who wear hearing aids and cochlear implants depend on the directional microphones that these devices have to pick up sounds. They are truly remarkable devices which are essentially micro computers that you wear on your ear. These devices are continually scanning and adapting to the changing environments you come across on the order of millions of calculations per second! They are powered by a button cell battery which when operated for 16 hours a day can last an average of 10 days.
No matter how advanced a hearing aid or cochlear implant is, they too have limitations. In the case of hearing in noise, arguably the most challenging of all hearing situations, a hearing aid or cochlear implant can only do so much. Ideally you want to be no more than six feet apart from the person you are talking with and that there is little to no competing noise in the area. The issue with competing noise is that it can "muddy up" the signal (voice of the person you are listening to). So what we are looking for is a very good signal to noise ratio (SNR). The better the SNR is, the easier it becomes to hear what it is you want to listen to. So a bigger SNR is always preferable than a smaller SNR.
In the case of Bart, which is notoriously noisy, your hearing aids/cochlear implants are trying to do the best job they can to filter out the signal you want to hear over the noise you do not. The problem is that they do not always know exactly what or who you want to hear. The acoustics in the environment could be really poor. Think tall ceilings and hard surfaces with lots of noise.
Enter the T-coil:
The T-Coil is a coil that resides in your hearing aid/cochlear implant if optioned that way. This coil is able to take the electromagnetic waves generated by a loud speaker, then reproduce the output of the speaker in the hearing aid/cochlear implant. The original intended use was for the telephone which would often cause a hearing aid to squeal if it came close to the ear. By switching to a telecoil mode on the hearing aid, the microphones of the hearing aid would be turned off, but the telecoil inside would then be able to receive the electromagnetic signal and allow for a much clearer sound. So in effect, we have bypassed the microphones of the hearing aid and poor acoustic situation as well allowing for a much better sound quality.
In larger rooms, you cannot always be close to the source of sound. So when a room is looped, the signal being played acoustically is also sent through an induction loop. Turn your hearing aid/cochlear implant over to T-coil mode and presto! You have now bypassed poor acoustics and improved your SNR by sending the sound directly to the hearing aids/cochlear implant.
Examples of places that are looped for sound, include airports, court houses as well as many museums. Even Stonehenge in England is looped for sound! Bart is starting the process, and should continue to improve on it over time.
Here are some links on the topic discussed today:
For more information on the T-coil, hearing aids or other hearing concerns call or e-mail me any time.
Your friend in Audiology,
Dr. Erik Breitling
