Although audio tapes and video tapes look different, they're based on the same principles.
尽管磁带和录像带看起来不同,但二者都基于同样的原理N=QhMFa4QjV;y85GX]U-。
Each has a roll of magnetic material which slides past the so-called “playback head” in the VCR or cassette deck (cassette decks have one playback head, VCRs have two or more).
录像机或盒式录音机(盒式录音机有一个放音磁头,录象机有两个或更多)都有能够滑过被称为“放音磁头”的磁性材料qxY4M1U,ql2。

In both machines, these heads detect changes in magnetism as the tape moves by.
这两种机器的磁头都会随着本身媒体的运动检测磁性的变化&WsyE9a_qv。
The changing magnetic signal is translated into music on your tape deck, or both video and sound on your VCR.
磁信号的改变转化为你录音机中的音乐,或录像机的视频和声音[x_)-BK9H-=。
Without a changing magnetic signal over a playback head, you'd get no sound, no picture.
如果放音磁头没有磁信号的变化,你就得不到声音和图像45##-xcpv4qrh39dlwx。