OG Passage 46 文章类型

(This passage was written in 1984.)

It is now possible to hear a recording of Caruso’s singing that is far superior to any made during

his lifetime. A decades-old way-cylinder recording of this great operatic tenor has been digitized,

and the digitized signal has been processed by computer to remove the extraneous sound, or

“noise,” introduced by the now “ancient” wax-cylinder recording process.

Although this digital technique needs improvements, it represents a new and superior way of

recording and processing sound which overcomes many of the limitations of analog recording. In

analog recording systems, the original sound is represented as a continuous waveform created by

variations in the sound’s amplitude over time. When analog playback systems reproduce this

waveform, however, they invariably introduce distortions. First, the waveform produced during

playback differs somewhat from the original waveform. Second, the medium that stores the analog

recording creates noise during playback which gets added to the recorded sounds.

Digital recordings, by contrast, reduce the original sound to a series of discrete numbers that

represent the sound’s waveform. Because the digital playback system “reads” only numbers, any

noise and distortion that may accumulate during storage and manipulation of the digitized signal

will have little effect: as long as the numbers remain recognizable, the original waveform will be

reconstructed with little loss in quality. However, because the waveform is continuous, while its

digital representation is composed of discrete numbers, it is impossible for digital systems to avoid

some distortion. One kind of distortion, called “sampling error,” occurs if the sound is sample (i.e.,

its amplitude is measured) too infrequently, so that the amplitude changes more than one quantum

(the smallest change in amplitude measured by the digital system) between samplings. In effect,

the sound is changing too quickly for the system to record it accurately. A second form of

distortion is “quantizing error,” which arises when the amplitude being measured is not a whole

number of quanta, forcing the digital recorder to round off. Over the long term, these errors are

random, and the noise produced (a background buzzing) is similar to analog noise except that it

only occurs when recorded sounds are being reproduced.

这种文章是我的弱点，怎么看都看不懂，正确率只有20%左右，

哪位朋友可以指点一下？

这种文章要读到什么程度，理解到什么程度才能在短时间内读懂？我觉得主要障碍是专业名词太多，句型类似，

难以对应问题找细节考点。哪位总结出一些方法呢？ 先谢了：)

我认为，楼主的问题不是“文章类型”所能解决的。建议看看OG的解释：

272. 对第一段的概括。认真看看文章后，你是否能如此概括呢？

This question asks you to select choice that best describes how the first paragraph (lines 1-7)

relates to the rest of the passage. The best answer is choice D. The first paragraph presents an

example of what may be accomplished with a modern digital recording and processing technique.

The remainder of the passage goes into detail about the technique itself. Choice A is not correct in

that the first paragraph presents a particular instance of digitization, not a general thesis. Choice B

can be eliminated: while the first paragraph does present a concrete example, it is an example of a

successful use of digitization, not an example of a problem. Choice C is incorrect because the first

paragraph is primarily concerned with presenting an example of a new process, not with

describing an old process. Choice E also can be eliminated because the first paragraph mentions a

historic recording, not a historic incident, and it does not describe a catalyst for developments

discussed elsewhere in the passage.

273.阅读过程中需要注意两种体系的异同。

This question asks you to identify something mentioned specifically in the passage that is a feature

of analog recording systems that is not shared by digital recording systems.

Choice B is the best answer. The passage states in lines 10-13 that analog recording systems

represent the original sound as a continuous waveform, while in lines 21-23 it notes that digital

recordings reduce the original sound to a series of discrete numbers. Neither A, D, or E are

features of analog systems, according to the passage. Choice C is not correct: while the passage

does say that analog recording systems distort the original sound, the passage also notes that “it is

impossible for digital systems to avoid some distortion” (lines 31-32). Thus some amount of

sound distortion is involved in both analog and digital recording processes.

274.对具体细节的细致判断。

To answer this question, you must use information contained in the passage to draw an inference

about the numbers by which sound is represented in digital recording systems. The best answer is

D because the passage states that storage and manipulation have little effect on the sound quality

of digital recordings. Since the sounds of a digital recording are represented by number, it may

thus be inferred that the numbers themselves are not easily altered by storage and manipulation.

Choice A is not correct: since the passage makes no mention of time intervals between successive

sounds, one cannot infer that the numbers describe such intervals. Choice B can be eliminated

because in its description of sampling error, the passage suggests that small changes in amplitude

are sometimes recorded inaccurately in digital systems. However, the passage does not indicate

that digital systems have difficulty modeling large changes in amplitude. Choices C and E are

incorrect because there is no indication in the passage that the numbers representing sounds in a

digital recording are altered in any way during playback, nor that the numbers are stored and read

in groups.

275. 如何进行有根据的推断。

To answer this question, you must use information contained in the passage to draw an inference

about the digital approach to sound processing. Choice E is the best answer. The passage notes

that it is impossible for digital systems to avoid some distortion, so it may be inferred that it is not

possible to digitally reprocess old recordings without at least some measure of distortion. Choice

A is not correct because the wax-cylinder process is characterized as “ancient” (line 7), while

digital recording is called “new and superior” (line 90. The wax-cylinder recording mentioned in

line 3 is described a “decades-old.” The suggestion thus is that the two processes were developed

at different times, not that they were developed in competition with each other. Both choices B

and D contradict information presented in the passage: it is stated that it is impossible for digital

recordings to avoid distortion completely (lines 29-32), and an example is provided in the first

paragraph of an analog recording being digitally reprocessed. While the statement in choice C

could be true without contradicting any furnish enough information to justify such an inference.

One kind of distortion, called “sampling error,” occurs if the sound is sample (i.e., its amplitude is measured) too infrequently, so that the amplitude changes more than one quantum (the smallest change in amplitude measured by the digital system) between samplings.

i can't understand it. who can translate it for me? thanks

楼主，如果考试时出现过于专业的文章，那你该感到高兴了，因为这样的文章一般问题都相对简单，大部分回原文定位很容易选到答案，不象简单明了的文章反而需要在答案之间斟酌。

以前我也怕这种文章，尤其是做GRE阅读题的时候。后来做多了，发现这类文章最好对付。很多题目都是一招搞定。MM可以把相关类型的文章分析几个，就能看出选项和问题设计的奥秘了。

比如这篇文章，除272题外，第273题，你只要找到文中analog recording system的位置（第11行），然后看这个词后面的内容，马上就可以确定选项B就是原文内容的缩写，连改写都算不上，一点隐蔽性都没有。

274，根据题干关键字找到第三段digital recordings，那么选项就在它这句下面的那句话里。只不过是做了点改写。

275infer题，则要求你对原文有整体的把握了，至少要知道选项中出现对digital缺点的评价要到原文哪里去对应，出现对它起源的论述要到哪里去对应。实际上这里infer出的内容并不是那种需要对作者意思揣测然后得出的。也只是对原文说法的一个改写，只是改写的较隐蔽。

以下是引用lindazhou在2005-6-16 10:06:00的发言：

One kind of distortion, called “sampling error,” occurs if the sound is sample (i.e., its amplitude is measured) too infrequently, so that the amplitude changes more than one quantum (the smallest change in amplitude measured by the digital system) between samplings.

i can't understand it. who can translate it for me? thanks

UP!

我是学理工的，学过模拟信号、数字信号。试着翻译：

有一种失真，称为“采样失真”，如果对声音（测量其振幅）的采样频率太低的话，那么采样点之间的振幅变化会大于一个quantum（数字系统中的最小振幅测量单位）。

比如mp3录音，可以选择采样周期（KHZ），采样周期越高，录出来的效果越好，

相反，如果采样周期too infrequently，那么失真肯定会大。

拙见。

太N了,一下就懂了,谢谢,尤其是那个MP3的比喻,强!

以後遇到這類型文章,就可以安心作題了