双语畅销书《艾伦图灵传》第6章:连接两个世界(7)
日期:2018-11-02 13:40

(单词翻译:单击)

Alan had probably already learnt about the Vocoder when in Britain, since Dollis Hill had received information on it in 1941.
艾伦在英国的时候,可能已经知道声码器了,因为邮政研究所从1941年开始,就用声码器来接收信息。
It was a very advanced piece of communications technology, which had been patented by the Bell engineer H. W. Dudley in 1935 and developed since then at the Bell laboratories.
这是一项非常先进的通信技术,1935年贝尔工程师H.W.达德雷注册了该专利,从此以后它就在贝尔实验室不断得到改进。
The idea of the Vocoder was to abstract the essential elements of speech, throwing away much of its redundancy, and conversely to reconstruct the speech signal from its essential components.
声码器的概念是,将声音的基本元素抽出来,去掉多余的元素,然后再用这些基本元素来重建语音信号。
One way of thinking of this process was to regard it as reducing the bandwidth, or frequency range, of a speech signal.
这个过程是为了降低语音信号带宽,或者说频率范围。
Any Bell Labs engineer would be familiar with the idea of reducing the frequency range of speech, since the telephone cut off sound above 4000 Hz.
贝尔实验室的任何一个工程师,对降低声音的频率范围都很熟悉,因为电话会削去4000Hz以上的声音。
The resulting lack-lustre tones were still perfectly comprehensible, the point being that higher frequencies were redundant in ordinary applications.
这使电话的声音总是死气沉沉,但完全可以听懂,也就是说,普通应用中并不需要更高的频率。
But to reduce that frequency limit much further would produce a sort of miserable grunting, which would not do at all.
但是,如果进一步直接削减频率,就会产生一种严重的嘟哝声,这就无法使用了。
The Vocoder did something far more sophisticated. It collected information about the amplitude of the speech signal at each of ten frequencies up to 3000 Hz,
声码器通过一种更精密的方式来削减频率,它在3000Hz以下的10个频率点上,
and also took an eleventh component which coded either the fundamental pitch of the sound or (during unvoiced sounds like ssss) an absence of pitch.
采集一个对应该频率的振幅信息,然后对其进行编码。
Each of these eleven signals required a frequency range of only 25 Hz.
这样编码出来的每个信号,频率范围只有25Hz。
In this way, sufficient information was abstracted for intelligible speech to be reconstructed, and yet the total bandwidth was confined to less than 300 Hz.
这样的方法,就能将语音信息需要的总带宽限制在300Hz以内,而且能保证足以能够听懂的语音质量。

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重点单词
  • rangen. 范围,行列,射程,山脉,一系列 v. 排列,归类于
  • sophisticatedadj. 诡辩的,久经世故的,精密的,老练的,尖端的
  • sufficientadj. 足够的,充分的
  • comprehensibleadj. 可理解的,易懂的
  • fundamentaladj. 基本的,根本的,重要的 n. 基本原理,基础
  • signaln. 信号,标志 v. (发信号)通知、表示 adj.
  • redundancyn. 冗余,备份,多余信息
  • componentn. 元件,组件,成份 adj. 组成的,构成的
  • miserableadj. 悲惨的,痛苦的,贫乏的
  • confinedadj. 幽禁的;狭窄的;有限制的;在分娩中的 v. 限