OG48-46(science?)(數位與類比錄音)

[agk99]

Passage 46 (science)(contrast A and B)
(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.
第一段：帶出數位化錄音可讓我們聽到卡羅素的歌聲，數位可以消除噪音，也就是消除那些由傳統老舊的wax-cylinder產生的聲音

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.
數位錄音克服許多類比錄音的限制，類比錄音會有一個問題，原音是一種連續波，到了再製階段，原音還是會一直遭受破壞，不但聲音與原音不同，儲存之後也會被添加一些雜音進去。

Digital recordings, by contrast, reduce the original sound to a series of discrete numbers that represent the sound’s waveform.(將原音轉為一系列的音波) Because the digital playback system “reads” only numbers,(數位化的特色) any noise and distortion that may accumulate during storage and manipulation of the digitized signal will have little effect(轉錄及儲存過程都不會受影響): 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(分離的) numbers, it is impossible for digital systems to avoid some distortion(還是有一些破壞). One kind of distortion, called “sampling error,” occurs if the sound is sample(採樣錯誤) (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(由於採樣錯誤，導致系統不能準確錄製). A second form of distortion is “quantizing error,” (量化錯誤)which arises when the amplitude being measured is not a whole number of quanta, forcing the digital recorder to round off.(圓滿完成) 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.

272. Which of the following best describes the relationship of the first paragraph to the passage as a whole?
(A) The first paragraph introduces a general thesis that is elaborated on in detail elsewhere in the passage.
(B) The first paragraph presents a concrete instance of a problem that is discussed elsewhere in the passage.
(C) The first paragraph describes a traditional process that is contrasted unfavorably with a newer process described elsewhere in the passage.
(D) The first paragraph presents a dramatic example of the potential of a process that is described elsewhere in the passage.
(E) The first paragraph describes a historic incident that served as the catalyst for developments described elsewhere in the passage.

273. According the passage, one of the ways in which analog recording systems differ from digital recording systems is that analog systems
(A) can be used to reduce background noise in old recordings
(B) record the original sound as a continuous waveform
(C) distort the original sound somewhat
(D) can avoid introducing extraneous and nonmusical sounds
(E) can reconstruct the original waveform with little loss in quality

*274. Which of the following statements about the numbers by which sound is represented in a digital system can be inferred from the passage?
(A) They describe the time interval between successive sounds in a passage of music.
(B) They model large changes in the amplitude of the initial sound with relatively poor precision.
(C) They are slightly altered each time they are read by the playback apparatus(設備).
(D) They are not readily altered by distortion and noise accumulated as the digital signal is stored and manipulated.
(E) They are stored in the recording medium in small groups that can be read simultaneously by the playback apparatus.
答案給D，要選一個不會被破壞的，little effect.....

*275. Which of the following can be inferred from the passage about the digital approach to the processing of sound?
(A) It was developed in competition with wax-cylinder recording technology.
(B) It has resulted in the first distortion-free playback system.
(C) It has been extensively applied to nonmusical sounds.
(D) It cannot yet process music originally recorded on analog equipment.
(E) It is not yet capable of reprocessing old recordings in a completely distortion-free manner.
A不對，wax-cylinder 是舊的，不會是形容digital recording....選E才對

[illuna]

我覺得本篇文章的架構是Specific-->General-->Specific

不知道大家意見如何?

另外Q275的答案C該如何解釋??我看了OG的說明不太了解C哪裡錯...

OG-Q275 Answer C

While the statement in choice C could be true without contradicting any furnish enough information to justify such an inference.

[bear]

橘子大哥....你的C選項解釋好像有漏掉.....(跳行)


275(C) 他解釋的意思就是說, 雖然C選項可以是對的而且沒有和文中的資訊相違背, 但是文中也沒有足夠的資訊infer它....

簡單歸納....C根本就是 not mention !!! 無關選項! ;)