VOA慢速英语2013 自然界和宇宙间各种各样的声音

 

Listening to Sounds - From the Earth and Beyond 自然界和宇宙间各种各样的声音

From VOA Learning English, this is Science in the News. I’m Avi Arditti.

And I’m Faith Lapidus. Today we tell you what natural event was found to be as loud as a strong earthquake. We also tell about mysterious and powerful radio signals that scientists say have come to us from far away. But first, we tell how free computer software can help with studies of animal populations.

Researchers have developed software that can listen to recordings² of a forest and tell us what animals are there. More importantly, the software can show what animals are not there. This new technology is available on the Internet, and free for anyone to use.

Here is a recording¹ of a rainforest in Puerto Rico. Listen closely, and try to count how many frogs you hear.

You probably had trouble counting the frogs. One of those animals -- the one making the really high-pitched chirp³ -- is endangered. It is called a Plains Coqui.

Thousands of species die out each year. Scientists want to know how climate change and land development are affecting animals like the Plains Coqui. But how can scientists know how many species are disappearing if they do not know how many there are?

New software can help them. It is called the Automated⁴ Remote Biodiversity Monitoring Network, or ARBIMON.

“It’s a generic⁵ system to monitor biodiversity.”

That is Mitchell Aide of the University of Puerto Rico. He is one of the leaders of the ARBIMON team. They hope the software program will help environmentalists study creatures worldwide.

“The software is set up for the user to use it for whatever species they’re interested in. It could be snapping shrimp⁶, or whales, or it could be frogs or insects or monkeys.”

Researchers place small, low-cost recording equipment in the rainforest. The equipment makes a recording every 10 minutes. The recordings are sent immediately to a central computer.

The scientists direct the computer to recognize the sounds of different animals. They then use the software program to examine tens of thousands of recordings in less than an hour. The software can identify which animals are in the rainforest and which are not. It can also show which ones are making sounds when, and which are not.

For example, when researchers studied five years of recordings from Puerto Rico, they found that the Plains Coqui called less and less over four years. This could have been evidence that the frogs were in danger. But in the fifth year, the frog sounds returned to earlier levels. This information about what appears to be the frog population’s natural rhythm would not have been available without a long-term study.

The team now has recording stations in Hawaii, Arizona, Costa Rica, Brazil and other places. Mitchell Aide says that over months, or even years, scientists can build a “sound picture” of the area and what lives there.

“We’re creating a permanent record. In a sense, each recording is the equivalent of a specimen⁷ in a museum. We’re going to archive these recordings so anybody can have access to ‘em today, or in five years, or in 20 years, and go back and say, ‘You know, what were the sounds like in this forest, in this city, on this island, you know, 15, 20 years ago?’”

The ARBIMON software and its collection of sounds are available to everyone at arbimon.com.

Human-made sound on the high seas may interfere⁸ with the ability of sea creatures to use sound effectively for guidance and communication. Researchers recently studied audio recordings made in the Antarctic Weddell Sea. They discovered that a melting iceberg⁹ can make a lot of noise, sometimes as much as a magnitude-4 earthquake.

Listen closely to this sound.

Some people might say that is a truck or a stringed instrument like a double bass¹⁰. But it is an iceberg pushing slowly against the sea floor.

“The iceberg is essentially¹¹ scraping along and more or less resonating, kind of like a tuning¹² fork.”

That is Robert Dziak of Oregon State University. He led a study of underwater noises around the Antarctic Peninsula, the northernmost part of the southern continent. He and his team of scientists recorded the sounds of an iceberg being born, as it separated from the ice of the mainland.

“We saw it from the beginning, the birth of the iceberg, to its actual eventual¹³ death, for lack of a better word.”

Mr. Dziak believes this is the first time anyone has listened to a single iceberg for all of its life. And he says what his team heard when the iceberg floated into the warmer Scotia Sea was surprising.

“As it begins to enter warmer water, it begins to melt. And it can melt catastrophically. The sound of this iceberg breaking apart was an incredibly loud sound, equivalent to several hundred supertankers in noise levels.”

Mr. Dziak says that is as loud as a small earthquake -- loud enough to be heard all the way up to Earth’s equator.

The oceanographers wondered if this much noise could be a problem for sea animals. Many of them use sound to travel, communicate and find food. Chris Clark is a bioacoustician at Cornell University. He studies the effect of underwater sound on ocean life.

“Whales, and fishes, as a matter of fact, and now even all the invertebrates¹⁵, like the lobsters¹⁶ and the shrimp and crabs¹⁷ and things like that, are all paying attention to sound. So there’s been this increasing awareness¹⁸ and concern about “Oh noise in the ocean.” Is it good, is it bad, are we indifferent, what’s going on?”

There are more and more human-created sounds in the ocean, from increased shipping¹⁹ traffic, seismic²⁰ testing and sonar equipment. Researchers are finding that the sounds are affecting sea creatures.

Chris Clark says the noise can make it impossible for animals to hear the things they need to hear.

“We refer to it as acoustic¹⁴ bleaching²¹. It’s as though suddenly there’s a big fog bank that just comes into where you’re living and suddenly you can’t see very far, only in this case the fog bank is noise.”

Chris Clark says temporary, natural sounds, like an iceberg breaking apart, may be as loud as an earthquake. But he says they are probably not as harmful to marine²² life as manmade sounds.

“It’s one thing to have evolved over 5 or 6 million years in a world that’s dynamic, with storms, with ice. The human-generated noise in the ocean is so chronically²³ persistent²⁴, it’s now a real concern, and it dwarfs²⁵ collective noise generated by icebergs²⁶.”

This is a time of warming oceans. Researchers say climate change may lead to more polar ice breaking apart, and making sounds as loud as earthquakes, in the Southern seas.

An international team of astronomers²⁷ recently reported discovery of four powerful radio bursts. The astronomers think the radio signals may have come from halfway²⁸ across the universe. They have a few theories about what might have produced the signals, but none of these theories have anything to do with strange, alien civilizations.

Astronomers observed a mysterious radio pulse coming from outside our solar system in 2007. Scientists had no idea what it was.

So a group of astronomers decided²⁹ to study the skies with a radio telescope. They searched for pulsars, neuron stars or parts of stars that had exploded.

Dan Thornton was the head of the group. He works for Australia’s Commonwealth³⁰ Scientific and Industrial Research Organization and the University of Manchester in Britain. He wanted to investigate the mysterious and powerful radio bursts. He also wanted to know if more were still being produced, where they came from and what would cause them.  

Dan Thornton says he and his team found more of these radio bursts as they examined the skies. And they learned that the bursts were real and not just common radio interference.

“What we’ve discovered is very, very narrow radio emissions³¹, so very short lived. They only last for a few milliseconds. The main thing that is interesting about them is that they appear to be coming from across the universe, so extremely far away. We get lots of these radio emissions a bit like this from our own galaxy³², from pulsars. But these appear to be coming from way, way outside our galaxy, a million times further away.”

He says his team measured only four of the radio pulses over a one-year period because they were studying only small areas of the sky at one time. He says it will take a few more years to complete the entire sky survey. He says it is likely that thousands more of these signals will be discovered.

The astronomers are not completely sure about the cause of these radio bursts. But they think they could be the result of some major cosmological event that took place billions of years ago. Mr. Thornton says astronomers need to continue their investigations³³ to better identify the source and cause of the radio bursts. One thing he is sure of is they are not coming from strange life forms.

His team says their research should help us learn more about space between the Earth and where the bursts took place. They say they hope to use the radio bursts to better understand some of the missing matter in the universe.

A report on the study was published in the journal Science.  

This Science in the News was written by Christopher Cruise. Our producer was June Simms. I’m Faith Lapidus.

1 recording   

n.录音，记录

参考例句：

• How long will the recording of the song take?录下这首歌得花多少时间？
• I want to play you a recording of the rehearsal.我想给你放一下彩排的录像。

2 recordings   

n.记录( recording的名词复数 )；录音；录像；唱片

参考例句：

• a boxed set of original recordings 一套盒装原声录音带
• old jazz recordings reissued on CD 以激光唱片重新发行的老爵士乐

3 chirp   

v.(尤指鸟)唧唧喳喳的叫

参考例句：

• The birds chirp merrily at the top of tree.鸟儿在枝头欢快地啾啾鸣唱。
• The sparrows chirp outside the window every morning.麻雀每天清晨在窗外嘁嘁喳喳地叫。

4 automated   

a.自动化的

参考例句：

• The entire manufacturing process has been automated. 整个生产过程已自动化。
• Automated Highway System (AHS) is recently regarded as one subsystem of Intelligent Transport System (ITS). 近年来自动公路系统(Automated Highway System,AHS)，作为智能运输系统的子系统之一越来越受到重视。

5 generic   

adj.一般的，普通的，共有的

参考例句：

• I usually buy generic clothes instead of name brands.我通常买普通的衣服，不买名牌。
• The generic woman appears to have an extraordinary faculty for swallowing the individual.一般妇女在婚后似乎有特别突出的抑制个性的能力。

6 shrimp   

n.虾，小虾；矮小的人

参考例句：

• When the shrimp farm is built it will block the stream.一旦养虾场建起来，将会截断这条河流。
• When it comes to seafood,I like shrimp the best.说到海鲜，我最喜欢虾。

7 specimen   

n.样本，标本

参考例句：

• You'll need tweezers to hold up the specimen.你要用镊子来夹这标本。
• This specimen is richly variegated in colour.这件标本上有很多颜色。

8 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。

9 iceberg   

n.冰山，流冰，冷冰冰的人

参考例句：

• The ship hit an iceberg and went under.船撞上一座冰山而沉没了。
• The glacier calved a large iceberg.冰河崩解而形成一个大冰山。

10 bass   

n.男低音(歌手)；低音乐器；低音大提琴

参考例句：

• He answered my question in a surprisingly deep bass.他用一种低得出奇的声音回答我的问题。
• The bass was to give a concert in the park.那位男低音歌唱家将在公园中举行音乐会。

11 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

12 tuning   

n.调谐，调整，调音v.调音( tune的现在分词 )；调整；（给收音机、电视等）调谐；使协调

参考例句：

• They are tuning up a plane on the flight line. 他们正在机场的飞机跑道上调试一架飞机。 来自《简明英汉词典》
• The orchestra are tuning up. 管弦乐队在定弦。 来自《现代汉英综合大词典》

13 eventual   

adj.最后的，结局的，最终的

参考例句：

• Several schools face eventual closure.几所学校面临最终关闭。
• Both parties expressed optimism about an eventual solution.双方对问题的最终解决都表示乐观。

14 acoustic   

adj.听觉的，声音的；(乐器)原声的

参考例句：

• The hall has a fine acoustic.这个大厅的传音效果很好。
• Animals use a whole rang of acoustic, visual,and chemical signals in their systems of communication.动物利用各种各样的听觉、视觉和化学信号来进行交流。

15 invertebrates   

n.无脊椎动物( invertebrate的名词复数 )

参考例句：

• Insects and worms are all invertebrates. 昆虫和蠕虫都是无脊椎动物。 来自辞典例句
• In the earthworm and many other invertebrates, these excretory structures are called nephridia. 在蚯蚓和许多其它无脊椎动物中，这些排泄结构称为肾管。 来自辞典例句

16 lobsters   

龙虾( lobster的名词复数 )； 龙虾肉

参考例句：

• I have no idea about how to prepare those cuttlefish and lobsters. 我对如何烹调那些乌贼和龙虾毫无概念。
• She sold me a couple of live lobsters. 她卖了几只活龙虾给我。

17 crabs   

n.蟹( crab的名词复数 )；阴虱寄生病；蟹肉v.捕蟹( crab的第三人称单数 )

参考例句：

• As we walked along the seashore we saw lots of tiny crabs. 我们在海岸上散步时看到很多小蟹。 来自《简明英汉词典》
• The fish and crabs scavenge for decaying tissue. 鱼和蟹搜寻腐烂的组织为食。 来自《简明英汉词典》

18 awareness   

n.意识，觉悟，懂事，明智

参考例句：

• There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
• Environmental awareness has increased over the years.这些年来人们的环境意识增强了。

19 shipping   

n.船运（发货，运输，乘船）

参考例句：

• We struck a bargain with an American shipping firm.我们和一家美国船运公司谈成了一笔生意。
• There's a shipping charge of ￡5 added to the price.价格之外另加五英镑运输费。

20 seismic   

a.地震的，地震强度的

参考例句：

• Earthquakes produce two types of seismic waves.地震产生两种地震波。
• The latest seismic activity was also felt in northern Kenya.肯尼亚北部也感觉到了最近的地震活动。

21 bleaching   

漂白法，漂白

参考例句：

• Moderately weathered rock showed more intense bleaching and fissuring in the feldspars. 中等风化岩石则是指长石有更为强烈的变白现象和裂纹现象。
• Bleaching effects are very strong and show on air photos. 退色效应非常强烈，并且反映在航空象片上。

22 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

23 chronically   

ad.长期地

参考例句：

• Similarly, any pigment nevus that is chronically irritated should be excised. 同样，凡是经常受慢性刺激的各种色素痣切勿予以切除。
• People chronically exposed to chlorine develop some degree of tolerance. 人长期接触氯气可以产生某种程度的耐受性。

24 persistent   

adj.坚持不懈的，执意的；持续的

参考例句：

• Albert had a persistent headache that lasted for three days.艾伯特连续头痛了三天。
• She felt embarrassed by his persistent attentions.他不时地向她大献殷勤，使她很难为情。

25 dwarfs   

n.侏儒，矮子（dwarf的复数形式）vt.（使）显得矮小（dwarf的第三人称单数形式）

参考例句：

• Shakespeare dwarfs other dramatists. 莎士比亚使其他剧作家相形见绌。 来自《简明英汉词典》
• The new building dwarfs all the other buildings in the town. 新大楼使城里所有其他建筑物都显得矮小了。 来自辞典例句

26 icebergs   

n.冰山，流冰( iceberg的名词复数 )

参考例句：

• The drift of the icebergs in the sea endangers the ships. 海上冰山的漂流危及船只的安全。 来自《简明英汉词典》
• The icebergs towered above them. 冰山高耸于他们上方。 来自辞典例句

27 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

28 halfway   

adj.中途的，不彻底的，部分的；adv.半路地，在中途，在半途

参考例句：

• We had got only halfway when it began to get dark.走到半路，天就黑了。
• In study the worst danger is give up halfway.在学习上，最忌讳的是有始无终。

29 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

30 commonwealth   

n.共和国，联邦，共同体

参考例句：

• He is the chairman of the commonwealth of artists.他是艺术家协会的主席。
• Most of the members of the Commonwealth are nonwhite.英联邦的许多成员国不是白人国家。

31 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

32 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

33 investigations   

（正式的）调查( investigation的名词复数 )； 侦查； 科学研究； 学术研究

参考例句：

• His investigations were intensive and thorough but revealed nothing. 他进行了深入彻底的调查，但没有发现什么。
• He often sent them out to make investigations. 他常常派他们出去作调查。