[HD2 Accessories] RecoveringSarcasmaholic:
You'd think so, it being a rubber belt and all (at least partially), but in fact, they're a static electricity GENERATOR.

I've been a treadmill repairman for 10 years, and I have seen some weird electrical stuff... I even have a video of some fibers "caught" in the treadmill belt's electrical static charge field, "orbiting" (not touching!) the rear roller like a moon!

Treadmills have a grounding system designed to discharge this static, which can malfunction, or may never have been correctly installed in the first place.

If you're getting mild shocks, there are 3 main potential causes (or combinations, but we'll assume for the sake of simplicity one is a main cause, possible contributing causes we'll attempt to eliminate later)

1. The headphones are at fault- I'd recommend repeating that experiment to verify you didn't confuse the old headphones with the new ones, I assume they're identical?

2. You're especially sensitive to electrical current- indicated by you reporting that you got shocked using two different headphones and two different music players.

Do you get mild shocks when holding the heart rate sensor grips on the treadmill? These work by sending a tiny electrical charge through your skin, and measuring the change in resistance as blood pumps through your skin, creating an average of your heart rate it then displays.

Most people don't feel this charge, some are sensitive to it and do.

3. The treadmill's static charge is too high, either just for you because you're oversensitive, or because the treadmill's ground system is not working, or not working well enough.

Try switching treadmills and see if you have the same problem. If not, notify the management that the other treadmill may need maintenance, the grounding system is there for a reason, and if it's not working, that static charge is slowly breaking that very expensive commercial treadmill.

Each resistor, capacitor, etc., every component in the electrical system has a 5-20% variance in what voltage it should be, so you may be better off on another treadmill.

You might also try cutting your salt/sodium intake, salt will make your skin more conductive, and cutting your salt intake is good for you anyway.

As I alluded to earlier, it might also be a combination of your sensitivity and the headphones or the treadmill. Maybe switching to a bluetooth headset would be the solution for you if you're overly sensitive.

Another possibility that occurred to me is that you may have a pimple deep inside your ear canal? Do you eat junk food, greasy food?

Whatever the cause, the voltages are not enough to make it a safety concern, just a comfort one. In other words, fatality is not possible.

Hope this helps!

O, btw, if you have a treadmill at home, check out the one-of-a-kind android app I wrote to help you keep your treadmill running at peak efficiency, there's a free one; Treadmill Tricorder, and a paid, much more sophisticated diagnostic / instructional / maintenance / repair app that will save you hundreds on maintenance and help you avoid breakdowns in the first place!

---------- Post added at 09:30 PM ---------- Previous post was at 09:22 PM ----------

For all our scientific advancement, there's still lots we DON'T know about electricity, like how a vacuum can hold a charge, etc.

Sometimes, the only way to see an effect is to build the product, and there will be minor variances in each thing produced, sometimes adding up to completely unexpected behavior; i.e., plastic being problematically conductive where normally it's level of conductivity is not enough to cause discomfort in 99% of users... best thing to do is let the manufacturer know what's happening, test the warranty replacement for same effect, if it still bugs you, it's either you or it, if there are no other pertinent factors...