by Neil Bauman, Ph.D.
One lady wrote:
Your article on loop systems just about convinced me that I should install a loop system in my office. What’s the next step?
I warned her that before she purchases any kind of loop system, she first needs to make sure that her office is reasonably free from electromagnetic interference.
Such interference is commonly produced by the 60 Hz. alternating current that flows through all the wires in the electrical system. Devices that cause interference include older fluorescent light fixtures, TVs, computer monitors (CRT monitors, not LCD monitors), electrical panels in the walls and sometimes the electrical wiring throughout the office.
You typically hear this interference as a loud buzzing sound when you have your hearing aids set to the “T” position.
The easiest way to tell if your office is reasonably interference-free is to turn your hearing aids to the “T” (t-coil) position, turn your volume way up, then move around your office and listen. If you hear a loud buzzing sound all over, then the office is too full of interference to effectively use your t-coils with a loop system.
If you only hear loud interference in one or two places, then as long as you place your desk (working area) in an interference-free spot, the interference shouldn’t bother you. However, since your computer and/or monitor may produce interference, you may have to lean away from the monitor to get away from the interference when using your t-coils.
Here’s a trick that will help keep the interference to as low a level as possible. Turn the gain on the loop system up so it produces a much stronger magnetic signal than the existing interference. Now you can turn the volume down on your hearing aids, thus making them less sensitive to the interference while still clearly hearing the signal off the loop.