Why do Fluorescent lights make that “Buzzing” Sound?

Why do Fluorescent lights make that “Buzzing” Sound?

If you’ve ever wondered whether or not your home or workplace has fluorescents, all you need do is open your ears and listen to the light. The familiar buzzing or humming sound coming from your lights is a common occurrence not only in your own home or office but in millions of others around the world. Some studies have shown that prolonged exposure to this incessant buzzing can lead to stress and irritability, which in turn can lead to diminished work performance.

So what’s the buzz about?

The scientific term for the phenomenon that causes this noise is called magnetostriction. The central element in a fluorescent light is a glass tube filled with an inert gas like argon and mercury. The inside of the tube is coated with a phosphorous powder that works to give the light its color. Electrodes at either end of the tube are wired to an electrical circuit. When the lamp is activated, a current moves through the electrodes. Since there is high voltage moving across the electrodes, electrons move rapidly from one end of the tube to the other. However, the current inside the tube must be limited in some way or it will rise continuously, tripping circuits in the home or office.

CFL Tube

Fluorescents lights use ballasts to keep the current in check. These ballasts are electromagnetic devices similar to inductors and are basically a bunch of copper wire wrapped around a solid iron core. When current is present and running through the ballast it creates a magnetic field which in turn slows the current – keeping it in check. The ballast makes this buzzing noise through magnetostriction – a phenomenon that takes place when the magnetic field produced by the ballast physically squeezes the iron core. Most lights in the U.S. operate at 60Hz, but thanks to magnetostriction, the core can be squeezed at nearly twice that rate, 120Hz – creating that all-to familiar humming sound.


A Simple Solution

With time, all tubes and ballasts need replacing as they degrade with the heavy electrical loads being put on them for countless hours day after day. One of the simplest solutions to cease the madness is to replace the bulb itself. If you have an older fluorescent light, you may need to replace the ballast. If you opt to replace the ballast, look into purchasing an electronic ballast. Electronic ballasts operate at 20,000 to 40,000Hz continuously and should completely eliminate buzzing and humming for good.

Don’t just eliminate the Buzz, Get rid of the Glare

Fluorescent bulbs don’t just plague our ears with never ending noise, they also give off ultraviolet waves that over time can irritate our eyes – leading to headaches, blurred vision, and decreased concentration. Get rid of the buzz and the harmful glare associated with fluorescent bulbs by using Diffuser Specialist’s Fluorescent tube guards. We have a wide variety of models and sizes available, and if we don’t have it – we’ll make it!

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1 Comment

  1. I’m weird in some good and bad ways with my hearing. It’s extremely sensitive. I can tell there diffrrence between 439 Hz and 440 Hz with an electronic wave generator and I also, unfortunately, hear the hum from the electronic ballasts @ just over 30khz

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