大象如何发出低沉的声音-凯发k8官网

大象如何发出低沉的声音
文章来源:未知 文章作者:enread 发布时间:2012-08-06 05:45 字体: [ ] 
(单词翻译:双击或拖选)
african elephants are known to be great communicators that 1 with extremely low-pitched vocalizations, known as infrasounds, over a distance of miles. these infrasounds occupy a very low frequency range -- fewer than 20 hertz, or cycles, per second -- that is generally below the threshold of human hearing. now, a new study shows that elephants rely on the same 3 that produces speech in humans (and the vocalizations of many other mammals) to hit those extremely low notes. 4 herbst from the university of vienna, along with colleagues from germany, austria and the united states, used the larynx(喉) of a recently deceased elephant to recreate some elephant infrasounds in a laboratory.
 
their findings are published in the 3 august issue of the journal science, which is published by aaas, the nonprofit science society.
 
"these vocalizations are called infrasounds because their fundamental frequency is below the range of human hearing," explained herbst during a phone interview. "we only hear the harmonics of such sounds, or multiples of that fundamental frequency. if an elephant's 2 folds were to clap together at 10 hertz, for example, we would perceive some energy in that sound at 20, 30, 40 hertz and so on. but these higher overtones are usually weaker in 5(振幅)."
 
until now, researchers have wondered whether these low, 6 elephant infrasounds were created by 7 muscle 8, as a cat's purr is, or by flow-induced vocal fold 10, fueled by air from the lungs, as is a human's voice. but, the natural death of an elephant at a zoo in berlin gave herbst and his colleagues a somewhat 11 chance to study the mechanism firsthand.
 
the researchers removed the elephant's larynx and froze it within a few hours of the animal's death. they then took it over to the larynx laboratory in the department of 12 biology at the university of vienna, where tecumseh fitch, a senior author of the science paper, studied it in depth.
 
herbst and the other researchers imitated the elephant's lungs by blowing controlled streams of warm, humid air through the 13 larynx while adjusting the elephant vocal folds into a phonatory, or vocal-ready, position. in this way, the scientists were able to 14 the vocal folds into a periodic, low-frequency 9 that matched an elephant's infrasound in every detail.
 
the fact that they were able to duplicate the elephant's infrasounds in a laboratory demonstrates that the animals rely on a myoelastic-aerodynamic, or "flow-driven," mode of speech to communicate in the wild. the elephant's brain would have been required to recurrently tense and relax the vocal muscles if the other mechanism, which produces a cat's purr, was involved, they say.
 
this flow-induced mechanism demonstrated by the researchers is likely to be employed by a wide range of mammals. from echolocating bats with their incredibly high vocalizations to african elephants and their extremely low-pitched infrasounds, this mode of voice production seems to span four to five orders of magnitude across a wide range of body sizes and sonic(音速的) frequencies.
 
the researchers also saw some interesting "nonlinear 15" in the way the elephant vocal folds vibrated. these mostly irregular patterns of vibration occur when babies cry or heavy metal singers scream and the physical mechanism that elephants use is again identical to that seen in humans, they say.
 
"if i scream, it's no longer a periodic vibration," said herbst. "it becomes 16 and you can hear a certain degree of roughness. this can also be observed in young elephants, in situations of high excitement."
 
herbst says that the findings were only made possible by a collaborative effort between voice scientists and biologists, and that voice science is an essential aspect of our social and economic lives.


点击收听单词发音收听单词发音  

1 7zwyi     
vi.谈话,谈天,闲聊;adv.相反的,相反
参考例句:
  • he can converse in three languages.他可以用3种语言谈话。
  • i wanted to appear friendly and approachable but i think i gave the converse impression.我想显得友好、平易近人些,却发觉给人的印象恰恰相反。
2 vhowa     
adj.直言不讳的;嗓音的;n.[pl.]声乐节目
参考例句:
  • the tongue is a vocal organ.舌头是一个发音器官。
  • public opinion at last became vocal.终于舆论哗然。
3 zcwxr     
n.机械装置;机构,结构
参考例句:
  • the bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • the mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
4 kvbyl     
adj.基督教徒的;n.基督教徒
参考例句:
  • they always addressed each other by their christian name.他们总是以教名互相称呼。
  • his mother is a sincere christian.他母亲是个虔诚的基督教徒。
5 nldyj     
n.广大;充足;振幅
参考例句:
  • the amplitude of the vibration determines the loudness of the sound.振动幅度的大小决定声音的大小。
  • the amplitude at the driven end is fixed by the driving mechanism.由于驱动机构的作用,使驱动端的振幅保持不变。
6 85a55a2bf439684a14a81139f0b36eb1     
n. 隆隆声, 辘辘声 adj. 隆隆响的 动词rumble的现在分词
参考例句:
  • the earthquake began with a deep [low] rumbling sound. 地震开始时发出低沉的隆隆声。
  • the crane made rumbling sound. 吊车发出隆隆的响声。
7 ebczv     
adj.间歇的,断断续续的
参考例句:
  • did you hear the intermittent sound outside?你听见外面时断时续的声音了吗?
  • in the daytime intermittent rains freshened all the earth.白天里,时断时续地下着雨,使整个大地都生气勃勃了。
8 322669f84f436ca5d7fcc2d36731876a     
n.收缩( contraction的名词复数 );缩减;缩略词;(分娩时)子宫收缩
参考例句:
  • contractions are much more common in speech than in writing. 缩略词在口语里比在书写中常见得多。 来自《简明英汉词典》
  • muscle contractions are powered by the chemical adenosine triphosphate(atp ). 肌肉收缩是由化学物质三磷酸腺苷(atp)提供动力的。 来自辞典例句
9 nldza     
n.颤动,振动;摆动
参考例句:
  • there is so much vibration on a ship that one cannot write.船上的震动大得使人无法书写。
  • the vibration of the window woke me up.窗子的震动把我惊醒了。
10 d94a4ca3e6fa6302ae79121ffdf03b40     
n.摆动( vibration的名词复数 );震动;感受;(偏离平衡位置的)一次性往复振动
参考例句:
  • we could feel the vibrations from the trucks passing outside. 我们可以感到外面卡车经过时的颤动。
  • i am drawn to that girl; i get good vibrations from her. 我被那女孩吸引住了,她使我产生良好的感觉。 来自《简明英汉词典》
11 cf73abfb75b644a95fbb19f85e4b95a9     
adj.偶然发现的
参考例句:
  • there was a serendipitous second advantage working with a library of equations. 利用方程库有个意外收获的附带好处。 来自互联网
  • strategic networking prepares us for serendipitous moments. 战略性人际交往让我们为不时之需做好准备。 来自互联网
12 uqwz0     
adj.认知的,认识的,有感知的
参考例句:
  • as children grow older,their cognitive processes become sharper.孩子们越长越大,他们的认知过程变得更为敏锐。
  • the cognitive psychologist is like the tinker who wants to know how a clock works.认知心理学者倒很像一个需要通晓钟表如何运转的钟表修理匠。
13 46cfe41f4659e8f94d950d30ccb93fb3     
v.切除,删去( excise的过去式和过去分词 )
参考例句:
  • certain passages were excised from the book. 书中某些段落已删去。
  • 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。 来自辞典例句
14 fqmz5     
v.哄诱,劝诱,用诱哄得到,诱取
参考例句:
  • i had to coax the information out of him.我得用好话套出他掌握的情况。
  • he tried to coax the secret from me.他试图哄骗我说出秘方。
15 8n9xp     
n.现象
参考例句:
  • ade couldn't relate the phenomena with any theory he knew.艾德无法用他所知道的任何理论来解释这种现象。
  • the object of these experiments was to find the connection,if any,between the two phenomena.这些实验的目的就是探索这两种现象之间的联系,如果存在着任何联系的话。
16 rutyd     
adj.混沌的,一片混乱的,一团糟的
参考例句:
  • things have been getting chaotic in the office recently.最近办公室的情况越来越乱了。
  • the traffic in the city was chaotic.这城市的交通糟透了。
上一篇: 下一篇:
tag标签: humans
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片
最新评论
网站地图