【英语语言学习】如何将声音永久保存

RACHEL MARTIN, HOST:
OK, here's a question. If a tree falls in the forest and someone records it, does the sound last forever? We are increasingly finding out that the answer is no. Fragile records from the 1940s are breaking, cassette tapes from the '80s are falling apart, not even digital is forever.
NPR's Emily Siner explores how the Library of Congress is trying to save millions of our nation's recordings 3 before they're lost.
EMILY SINER, BYLINE 4: When an archaeologist discovers fragments of a civilization, the result is pretty incredible. Just listen to Andrea Berlin. She's an archaeologist and professor at Boston University, and her very first dig was in southern Israel.
ANDREA BERLIN: I found myself excavating 5 the room of a house that somebody had lived in, in around 800 BCE.
SINER: Oh, my gosh.
BERLIN: That's what I thought. I felt like a time traveler.
SINER: Berlin studies people in the Mediterranean 6 from 2- or 3,000 years ago. She finds their sculptures and tools, and lots of pottery 7. But one thing she doesn't find is their audio.
BERLIN: I think archaeologists are jealous of historians who have modern information sources - audio, for example; individual interviews and shows and recordings.
SINER: Because sound adds another layer of context to history. Gene 9 DeAnna at the Library of Congress has an example.
GENE DEANNA: Hearing Martin Luther King's "I Have a Dream" speech.
(SOUNDBITE OF ARCHIVED RECORDING 2)
THE REV 1. DR. MARTIN LUTHER KING JR: I have a dream that one day, this nation will rise up and live out the true meaning of its creed 10...
DEANNA: To hear him say it, rather than read the words, is a much more visceral and significant, I think, medium for it.
SINER: DeAnna oversees 11 the library's decades-long project to digitize the sounds of the past, from iconic speeches...
(SOUNDBITE OF ARCHIVED RECORDING)
PRESIDENT FRANKLIN D. ROOSEVELT: That the only thing we have to fear is fear itself...
SINER: ...to patriotic 12 songs from World War I...
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED SINGER: (Singing) Make your mother proud of you and the old red, white and blue
SINER: ...to operatic tenor 13 Enrico Caruso, singing in 1904.
ENRICO CARUSO: (Singing in foreign language)
SINER: But preserving audio is a bigger job than it sounds. When working with old formats 14, it's a race against time. With wax cylinders 15 from the 1890s, the heat from your hands can cause them to crack. Records made of glass during World War II are so fragile that they can break even when they're handled properly. And DeAnna says if it's on a cassette tape, it's automatically at risk.
DEANNA: No matter how well it was recorded, by whom, on what equipment, it's on a cassette, and it's just a terrible format 8 for archiving.
SINER: So this is a big job. They're digitizing about 15,000 recordings a year. And that's only a fraction of what they have.
DEANNA: We're probably acquiring between 50- and 100,000 a year. We're at least stabilizing 16 them in a good environment so that their deterioration 17 will slow down. And we'll, hopefully, get to most of them before they're lost.
SINER: The good news is, they're not the only ones working on it. Other institutions - like the Harvard Library and Lawrence Berkeley National Laboratory - are also making strides in preserving audio. The trick is preserving not only the audio from the past, but also the audio we're recording today.
Andrea Berlin says if that survives, future archaeologists will be thrilled.
BERLIN: I'm always thinking: Well, in 200 years and in 500 years and in 1,000 years, there will be other people studying us. Maybe they'll be able to hear us.
SINER: Emily Siner, NPR News, Washington.