school student Jay Thaker to a meeting of heart specialists looked at the effect of Ipods on 100 patients, whose mean age was 77, outfitted with pacemakers.The population tested in Thaker's study had a mean age of 76.1 (plus or minus 8.6 years), which is admittedly not the prime demographic for iPods and other MP3 players. When an iPod was held above five centimeters from the chests of the patients for five to 10 seconds, electrical interference was detected in about half of the 800 trials.
Pacemakers misfired because they may have mistaken electronic signals from iPods as a rhythm problem, said Thaker. Since pacemakers keep a record of heart rhythms, it's possible that interference could lead doctors to misdiagnose a patient. It is still unclear if all music devices pose the same problem as this test was done with iPods only.
Fortunately the sort of people who have pacemakers rarely buy an iPod.