A new research conducted at the Medical Device Safety Institute at Beth Israel Medical Center in Boston reached the conclusion that the magnets used for headphones have the potential to affect pacemakers and implanted defibrillators. There have been many rumors about the dangers of listening to music on digital players, with an intense focus on the iPod, but the threat is generated only by the headphones.

In order for the headphones to affect the devices, they must be positioned right next to the pacemaker, over the heart, so any sort of complications can be easily avoided by keeping the player and its headphones away from the area when it is not in use – people must put it in a backpack instead of their front shirt pocket.

The study involved eight models of headphones which were tested with 60 patents with defibrillators and pacemakers. The conclusion was that the magnets found in each headphone, which are rather powerful, can derail the electrical impulses which are sent from the device to the heart, which can lead to palpitations and arrhythmia. The problems were reported for one in four patients and the biggest issues were recorded with the ones using a defibrillator.

The procedure demanded the patients to keep a set of headphones directly on their chest, while the researchers monitored and recorded every single impulse, in order to find the evidence on the two devices’ interaction. Detectable interference was noted for 15 percent of the pacemaker patients and 30 percent of the defibrillator patients, which can be considered enough to agree that there is indeed a connection between the two and issue a warning for the people using such devices.

Study leader Dr. William Maisel explained that the report is meant to inform and not panic anyone. "The main message here is: it's fine for patients to use their headphones normally, meaning they can listen to music and keep the headphones in their ears," he said, adding that "what they should not do is put the headphones near their device. […] I certainly don’t think people should overreact to this information, but it’s smart to keep small electronics at least a few inches from implanted medical devices, and not let someone wearing headphones lean against your chest if you have one," he also stated, concluding that "The headphone interaction applies whether or not the headphones are plugged in to the music player and whether or not the music player is on or off."

The warning also included other instructions, such as to keep the headphones at least 3 centimeters away from the implantable devices, as many music player users tend to leave the headphones hanging by their necks down the chest when not listening to their tunes.

This year’s American Heart Association Scientific Sessions (AHA) released the results of other tests, announcing that pacemakers or implanted defibrillators are not affected by iPhones, iPods or any Bluetooth headsets, putting an end to all the speculations and concerns.