闲着没事儿翻译些国外教学用的资料，声音合成知识

alickjack

What's In A Synth? 何为声音的合成？
by Terry Decker 翻译：赫铁龙 Alick

Modules in a software synth Reaktor by Native Instruments. Reaktor is a complete tool kit for building synths simple and complex, and it's really well suited for us to start simple and gradually add building blocks until we've built a pretty impressive synthesizer.
为了更好的解释和阐述，我们使用的是Native Instrments公司的产品Reaktor软件合成器中的模块。Reaktor是一个可以用来合成无论简单还是复杂的声音的完全套件，非常适合我们从简单的声音合成开始，循序渐进地增加合成器的模块，直到我们可以搭建出一个真正令人印象深刻的合成器。

Okay, let's get started. First off, we'll define some words and draw some lines in the sand. A synthesizer's guts can be broken up into two basic parts, although as we'll see there can be some overlap. One is the audio path, the part of the synth where the actual sound goes. In our basic synth model, the audio is created, then shaped in various ways, then sent out to where we can hear it. Outside of the audio path is the modulation structure, where we can control how the sound is shaped. Actual audio doesn't pass through this part, but it tells the audio path what to do. (To modulate means to change; in a synth, modulation is the way we control how a sound behaves.)
好的，让我们从这里开始。首先，我们将定义一些词语，并且在沙子中画几条线出来。合成器的内部通常可以分为两部分，虽然我们经常会看到在界面中他们总是叠加在一起的。第一个部分是音频路由，这是声音在合成器中必须经过的路径。在基础合成器模型中，声音在建立后会被处理成为不同的形式，然后被发送出去直到我们可以听见它。那么除了音频路由以外，第二部分就是调制模块，我们就是在这里决定声音会成为何种样式，也就是声音是怎样被处理的。实际上声音不从这里经过，但是它的作用是告诉音频路由该怎样去处理。（调制意为改变或者编辑声音；在合成器中，调制就是我们控制声音如何去表现。）

So when we have a synth sound (often called a patch), there will be parts of the description of that sound that involve the audio path and other parts that involve modulation (mod for short) sources and destinations. All of these parts can be thought of as building blocks or modules in the sound, and we can graphically visualize a sound with a block diagram, drawing connections between blocks.
所以，当我们拥有一个合成的声音（或称为patch），我们就可以从以下这两个方面来对这个声音进行描述：一个是音频路由，另一个是调制的起始形式与目标形式。我们可以把所有的这些部分想象成声音的构建模块，从而我们就能以图形的形式将声音视作一个模块图表，在不同的模块中用直线来连接。

We'll start next time by getting a sound out of Reaktor with an audio source. From there we'll build up a complete audio path by the end of Part 5, and then we'll start adding modulation sources to finish our synth.

Part 2. Oscillators and waveforms 振荡器与波形

So how do we start building a synth sound? With something that makes noise. Traditionally this is a device (a vacuum tube, transistor array, IC chip, or software code) that creates a steady tone at a particular frequency: an oscillator.
那么，我们该如何合成一个声音呢？答案是用某种能够制造噪音的东西。通常来说是一个设备（可能是真空管，晶体管阵列，集成电路或者程序软件），能够创造出一个特定频率的声音，这就是振荡器。
Oscillators in synths usually create waveforms that are periodic. That means that the shape of the waveform coming out of the oscillator repeats itself periodically. The period is very short, from tenths of a second to thousandths of a second (milliseconds or msec for short), and as a result the frequency ranges from about 20 Hertz (a Hertz, Hz for short, is one cycle per second) up to about 20,000 Hertz (20 kiloHertz or kHz), the range of human hearing.
合成器中的振荡器是产生一个具有周期性的波形的设备。这意味着从振荡器中产生的波形会以一定的周期不停地重复。而波形重复的周期是十分短暂的，一般来说从一毫秒到0.1秒不等，这样的结果便是声音的频率范围在20Hz到20000Hz之间，也就是人类的听觉范围。（Hz 赫兹，频率的单位。频率与周期互为倒数关系。）
This is a pretty heavy simplification. In fact, synths make use of waves that are both much slower than this, below the audio range, and can produce sounds that are much higher than this (depending on the design).
这样说只是简单的描述了一番。实际上，合成器能够处理比人类的频率听觉范围下线低很多的声音，同样，也能够处理比听觉上线还要高的声音。
The simplest possible waveform is the sine wave, which consists of a tone at one frequency and nothing else. They can be useful for some things (like teaching you guys about oscillators!), but they're not very interesting to listen to. Why not? Because when you listen to a sine wave, all you're hearing is a single frequency we call the fundamental. Normally in the real world, a sound at a particular pitch carries the fundamental plus a series of higher frequencies that are related to the fundamental in complex ways: these are called harmonics.
最简单的波形叫做正弦波，它简单到只包括一个频率和声音而别无其他。而它的作用在某种意义上来说也是比较重要的，例如能让我们知道什么是振荡器！但是正弦波听起来却不是那么有趣。为什么呢？因为在我们听正弦波声音信号的时候，我们所能听到的只有一个单一的频率，也成基频（或基音），是一个声音最基本的元素。然而在真实的世界中，一个具有固定音高的声音除了包含基频以外，还会包含一系列的谐频（或谐音），这些谐频与基频有着不同种类的关系。
Every tonality we hear has a different harmonic structure, and that harmonic structure changes over time. A saxophone playing a high C sounds different from a violin playing the same note because their harmonic structure is different.
我们所听到的不同的音调有着不同的谐频结构，并且这个谐频结构会随着时间的推移产生变化。我们打个比方，一个萨克斯发出的高音C与小提琴发出的高音C在音色上是十分迥异的，他们的基频都是一样的频率，也就是高音C的频率，而区别就在于谐频的不同。所以谐频才真正地决定了一个音色。
When we look on an oscilloscope (a device for visually displaying what a waveform's shape is, we see that adding harmonics to the fundamental changes the shape of the wave. The more harmonics, the more rich and tonally interesting the wave becomes. Naturally, we want as much interest as we can get in our sounds, and there are a lot of ways to get there.
在我们观察示波器（用来显示波形形态的设备）的时候可以发现，在基频上面增加谐频可以很大程度上改变声音的形态。增加的谐频越多，声音就会变得越来越丰富而有趣味。我们经常会喜欢创造趣味横生的声音，并且我们拥有非常多的方法使之得以实现。
One method is to use the fact that certain waveforms are easy to make with simple circuits and naturally contain a huge array of harmonics to play with. Common waveforms you'll see on analog synths include the triangle wave, the sawtooth wave, the square or pulse wave, and noise (there are various kinds of noise, but the one we're mainly interested in is white noise, where each frequency is equally represented). These all have differing harmonic content, and will be our starting point. (There are other ways to get at interesting sounds, like sampling, additive synthesis, FM and phase distortion, etc…
方法之一就是运用简单的电路来生成具有大量谐波的的波形。通常我们在模拟合成器中所能接触到的波形有三角波，锯齿波，方波和脉冲波，还有噪音（噪音有很多种，但是这里我们只讨论一种叫做“白噪”的噪音。所谓白噪音是指一段声音中的频率分量的功率在整个可听范围（0～20KHZ）内都是均匀的。由于人耳对高频敏感一点这种声音听上去是很吵耳的沙沙声。 粉红噪音 粉红噪音是自然界最常见的噪音，简单说来，粉红噪音的频率分量功率主要分布在中低频段。）除此之外，我们还有很多获得很有趣的声音的方法，例如采样，加法合成，FM合成以及相位失真等等，这些我们以后将做具体探讨。

qyjs

长见识了，国外的教学用资料值得借鉴，有一定的参考价值。加分鼓励！

HappyX

算是入门资料吧。。。不过非常不全，只讲了点不全的皮毛

alickjack

回复 3# HappyX


    为论坛做点贡献，呵呵，闲着也是闲着么

HappyX

呵呵~Korg论坛上有个帖子不错~有时间我翻译一下去~那个相对比较全~

轻音大爱

在MIDIFAN论坛就有声音合成教程
不过连接挂了网站管理员也不补上