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Headphones used with MP3 digital music players like the iPod may interfere with heart pacemakers(起搏器) and implantable defibrillators(除颤器), U. S. researchers said.
The MP3 players themselves posed no threat to pacemakers and defibrillators, used to normalize heart rhythm. But strong little magnets inside the headphones can confuse the devices if placed within 1. 2 inches of them, the researchers told an American Heart Association meeting in New Orleans.
Dr. William Maisel of the Medical Device Safety Institute in Boston led a team that tested eight models of MP3 player headphones in 60 defibrillator and pacemaker patients.
They placed the headphones on the patients’ chests, directly over the devices. The headphones interfered with the heart devices in about a quarter of the patients--14 of the 60--and interference was twice as likely in those with a defibrillator than with a pacemaker.
Another study presented at the meeting showed that cell ph
A. MP3 players can interfere with heart, pacemakers and defibrillators.
B. The magnets inside the headphones can interfere with pacemakers and defibrillators.
C. The loud music beats pose a threat to pacemakers and defibrillators.
D. MP3 players are placed too close to pacemakers and defibrillators.

Headphones used with MP3 digital music players like the iPod may interfere with heart pacemakers(起搏器) and implantable defibrillators(除颤器), U. S. researchers said.
The MP3 players themselves posed no threat to pacemakers and defibrillators, used to normalize heart rhythm. But strong little magnets inside the headphones can confuse the devices if placed within 1. 2 inches of them, the researchers told an American Heart Association meeting in New Orleans.
Dr. William Maisel of the Medical Device Safety Institute in Boston led a team that tested eight models of MP3 player headphones in 60 defibrillator and pacemaker patients.
They placed the headphones on the patients’ chests, directly over the devices. The headphones interfered with the heart devices in about a quarter of the patients--14 of the 60--and interference was twice as likely in those with a defibrillator than with a pacemaker.
Another study presented at the meeting showed that cell ph
A. headphones had interference with the heart devices in every patient
B. half of the models of MP3 player headphones had interference with heart devices
C. headphones had much stronger interference with a defibrillator than with a pacemaker
D. headphones had much stronger interference with a pacemaker than with a defibrillator

Passage One
Headphones used with MP3 digital music players like the iPod may interfere with heart pacemakers (起搏器) and implantable defibrillators (除颤器) , U.S. researchers said.
The MP3 players themselves posed no threat to pacemakers and defibrillators, used to normalize heart rhythm. But strong little magnets inside the headphones can foul up the devices if placed within 1.2 inches of them, the researchers told an American Heart Association meeting in New Orleans.
Dr. William Maisel of the Medical Device Safety Institute in Boston led a team that tested eight models of MP3 player headphones, including clip-on and earplug types, in 60 defibrillator and pacemaker patients.
They placed the headphones on the patients’ chests, directly over the devices. The headphones interfered with the heart devices in about a quarter of the patients--14 of the 60--and interference was twice as likely in those with a defibrillator than with a p
A. MP3 players can interfere with heart pacemakers and defibrillators.
B. The magnets inside the headphones can interfere with pacemakers and defibrillators.
C. The loud music beats pose a threat to pacemakers and defibrillators.
D. MP3 players are placed too close to pacemakers and defibrillators.

MP3 Players take the music experience to an entirely new level, freeing those on the go (忙碌，活跃) from bulky(体积大的) CD players. MP3 Players are very small and lightweight. Modem MP3 Players can hold hundreds of songs and play them in any order you want. You can use your MP3 Player to create your own mix of music. You can transfer selected songs from your favorite CDs or download them from the Internet for a very low fee.
The MP3 Format
MP3 Players use the MP3 format, which is a very efficient compression (压缩) system for music files. And it performs this compression with little or no noticeable difference in sound quality.
MP3 Player Features
Size -- In general, the smaller the MP3 Player the better. There are several MP3 Players on the market that aren’t much larger than a postage stamp!
Computer Connection -- Most MP3 Players today connect to your PC via a standard USB port.
Memory -- Th