It may sound like something you’ve heard about before. And, if so, you may also remember that allegations of iPods and other portable music players interfering with heart pacemakers were disproven by medical researchers.

But, now, doctors and engineers are looking into reports that music player headphones can interfere with both pacemakers and implantable defibrillators.

Dr. William Maisel of the Medical Device Safety Institute at Beth Israel Medical Center in Boston notes that his team’s research has not been focused on electromagnetic emissions given off when the players are operating. In fact, he says the devices don’t even have to be turned on to constitute a danger.

The problem centres on the tiny, powerful magnets in the headphone speakers. Maisel told the American Heart Association conference in New Orleans, LA, this past weekend, that portable media player headphones or ear buds can interfere dangerously if placed within 1.2 in. / 3.0 cm of implanted devices.

Incidentally… Another paper presented at the conference concluded that Bluetooth wireless cell phone headsets are not likely to interfere with pacemakers or implanted defibrillators.

The moral of the story: If you have a pacemaker or defibrillator, don’t carry your music player earbuds in your breast pocket!