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噪音的颜色

The Colour of Noise - Sixty Symbols

So you’ve heard a white noise.
你应该听说过白噪音
Did you know there was pink and blue noise?
但你知道还有粉色或蓝色的噪音吗
And indeed perhaps green noise, and red noise, and a whole range of other noises.
而且可能还有绿色 红色等等各种噪音
Where do all those different colors come from?
不同颜色的噪音来自哪里?
And what is white noise anyway?
白噪音到底是什么?
How can noise have a color?
噪音怎么会有颜色?
Yeeh,so I can just do it here. There we go, yeah
我只好在这里试一下了 来吧
Okay, that’s white noise.
这是白噪音
So that’s the sound of a signal,
那是信号的声音
which has absolutely no periodicity to it.
完全没有周期性
It’s entirely and utterly random.
完全随机的
Why we called it white noise
我们为什么叫它白色噪音
Well, we call it white noise in an analogy with spectrum,
我们叫它白噪音是为了跟光谱做类比
with spectrum of light from a rainbow, for example, or any type of spectrum.
任意类型的光谱 比如彩虹
So all frequencies contribute equally.
所以 所有输出光的频率都是一样的
So just as you have with white light
正如你认为白光
all colors contribute equally, in this case, all frequencies.
所有颜色的光是均匀的 同时所有频率也是如此
What does that mean?
那意味着什么
Well, you can think of a wave
你可以想象一个波浪
and a wave varies in time.
一个随时间变化的波
So if it’s varying with a slow frequency,
如果它以很低的频率变化
it’s changing on slow timescales.
改变的尺度很小
And it’s not, you know, very rapid.
不是非常快
But then you can also have high frequency waves,
但你也可以想象一个
which oscillate back and forth very very quickly.
反复快速震荡的高频波
So you get a difference between a tu tu tu tu and tu tu tu….
然后你会在突 突和突突之间感觉到差异
That’s what I’m talking about.
这就是我想说的
You mix those all together all those different frequencies
你把所有不同频率的波混合起来
from the very very slow to the very very high,
从超低频率到超高频率
and you mix them all together equally.
然后你无差别地混合它们
And what you get is white noise.
这就是白噪音
So what you were hearing was a sample of white noise,
那么你现在听到的是在一台
which has been generated very simply on a computer,
电脑上简单制作而成的白噪音
which covers frequencies from very very low close to zero Hertz
这个噪音频率覆盖了从接近零赫兹
all the way up to about 20 kilohertz, something like that.
一直到20千赫兹左右的频率 差不多
And it’s an equal mixture of all those frequencies.
而且是把所有频率均匀地混合起来
And that’s what this is showing us.
这就是白噪音
It’s showing us the power associated with each frequency.
这个频谱展示了功率与频率的关系
And so you mix it all up so all the powers contribute equally,
你把它们混合在一起 所有频率都一样
and what you get is white noise.
那么你得到就是 白噪音
So that’s a spectrum for white noise.
这就是白噪音的频谱
So just as we have, you know,
所以就像我们听到的
if you have a pink color or a red color or a blue color in terms of light,
如果你看到过粉色 红色 蓝色的灯光
It means that certain frequencies are dominating,
这意味着一些频率占主导
certain waves and certain frequencies are dominating.
一些波和频率站主导地位
If you’ve got pink noise,
如果现在是粉噪音
then what you have is the lower frequencies,
那你会看到一个更低频率的频谱
which are moving towards the red end of the spectrum
它的频率偏向频谱的红色端
or contributing more.
甚至更加往后
So for you, if we look at aspect for a pink noise.
如果我们看粉噪音的频谱
You hear any difference at all?
你听到一点不同吗
Was that lower…was that supposed to be a lower pitch?
更低了 应该是更低的音吧
So, well, it’s no, it’s… that’s meant to be pink noise.
这就是粉噪音
So it’s meant to be different from white noise.
与白噪音不同
Can you hear any difference?
你能听出差别吗
We’ll replay the two back to back and see if you can hear any difference.
反复播放几次 看你能不能听出差别来
Can you hear that lower frequency rumble?
你能听到更低的声音吗
-Yeah, it’s deeper. -It is. It’s deeper.
-是 声音更沉 -对 更沉
And that’s what we’d expect,
这就是我们说的
because in this case when we look at the frequency spectrum,
因为在这情况下当我们看着频谱时
then what we find is instead of it being flat, it tails off.
我们会发现频谱不是平的 而是在降低
So what we have is the lower frequencies contribute more than the higher frequencies.
可以看到低频参与度高于高频
So we hear that rumble
我们听到低声
and in fact the 1/f noise if you listen to it again.
其实你再听一遍 这就是1/f噪音
Sounds rather like rainfall.
听起来很像是雨声
Listen, those’ve must been sitting inside the unison of the rain outside.
听 这些声音一定是外面雨的合奏
– Okay. – Did you just said 1/f?
-好的 -你刚才说1/f
Yes, did I just say 1/f?
没错 我刚说了1/f?
Okay, yeah, so that’s how the frequency spectrum goes.
这就是频谱怎样表现的
So the the power in this case goes inversely with the frequency.
这种情况下 功率与频率成反比
So as we’re going up in frequency,
只要频率增加
the power is dropping down,
功率就下降
so it goes as 1/f.
所以它下降到了1/f
So the white noise has no dependence.
但是白噪音无踪迹可寻
So no depends on frequency, so it’s a constant, so it’s flat.
在频率上毫无踪迹 它是一个常量
So, but we can alter of blue noise.
但是我们可以改变蓝噪音
And you can probably guess what’s blue noise is.
你可能会想蓝噪音是什么
-That’s not blue noise. -That’s not blue noise.
-那不是蓝噪音 -那不是蓝噪音
Yes, that’s certainly got a periodic tone.
对 那是一段有节奏的曲调
Hello, [laugh]
你好 [笑]
With 1/f, so it falls off with frequency.
1/f噪声 频率逐渐减小
So it’s inversely dependent on frequency.
而蓝噪音在频率趋势上是相反的
If we have blue noise,
如果是蓝噪音
then you probably can guess what it’s going to do.
你应该能猜到蓝噪音是怎样的了
But, let’s have a listen to blue noise first of all.
先让我们来听一下蓝噪音
The power last time was proportional to 1/f, so it’s falling off with frequency.
上一次的功率跟1/f是相对应的 所以频率降低
Now it’s proportional to F, so it’s growing with frequency.
现在的功率对应F 所以频率就变大
And it’s exactly the same, so what we’re doing with 1/f?
同样的 如果对应1/f会怎么样?
It’s what waiting it towards the lower frequencies getting redder or getting pinker.
等待着它的是朝频率更低的红色或者粉色
What we’re doing now is we’re waiting it towards higher frequencies getting bluer.
我们现在就等它偏向更高频率 变得更蓝
When I think of white noise,
当我想象白噪音
I think of that fuzz on the TV.
我会想起电视上模糊的屏幕
What’s that?
那是什么
That’s exactly, that’s a visual representation of what we’re hearing here,
对的 那就是噪音在屏幕上的视觉化
in terms of exactly the same idea,
同样的概念换种说法
where we get a great deal of frequencies all contributing together.
各种不同的频率共同形成这样的白噪音
Once we have all those frequencies contributing,
一旦我们发现所有频率都相同
so we don’t have a spectrum with a ramp like it on this,
频谱不是像这个样子的斜坡
where it’s a flat spectrum.
而是一个平坦的频谱
We call that white noise,
就称为白噪音
in some cases, depending on the equipment you have;
有时取决于你的设备
and depending on the type of setup you have;
取决于你的装置类型
and depending on how your area is working.
也取决于你是如何调制的
You might have deviations from white noise.
你听到的也许会跟白噪音有一些差异
But your white noise means that you have got up everything contributing to the same extent.
但是白噪音意味着 所有频率占比相同
You’ll get a lot of websites saying that
你会知道许多网站
what you should do is fall asleep with pink noise,
建议你应该伴着粉噪音入眠
because it gives you a more sort of harmonious brain rhythm.
因为粉噪音会给你一种和谐的节律
There seem to be some papers that make suggestions along those lines.
似乎有一些基于这些想法提出建议的论文
I’m not entirely convinced
但我并不完全相信
I’ve got to admit, I must admit that
但我得承认 我必须承认
part of me thinks that what we should do pretty
我应该做的就是记录下大量的
is just record a lot of white noise and pink noise and blue noise,
白噪音 粉噪音 蓝噪音并将它们
and send it out there in charge.
发送给负责人
Charge a little bit of money for it so I think we could set up a business fairly quickly.
收一点钱 这样我们就能很快地做点生意
I wanna hear black noise, you always wear black.
我想听黑噪音 你总是穿黑色
Oh, that’s interesting, there is indeed, there is even black noise.
噢 那真有趣 真的有黑噪音吗
There is black noise.
的确有黑噪音
-So. -What’s black that show there is no noise.
-所以 -黑代表无噪音
Yeah, exactly, that’s exactly what it is.
对 就是那样
Black noise is an absence of any noise at all.
黑噪音意味一点噪音也没有
It’s, but, it’s even to find you can find a wiki entry on black noise,
但你却能在维基找到关于黑噪音的条目
which I didn’t even realize until very recently.
我最近才知道
-That’s what we should do, so black noise. -Yes. [laugh]
-我们应该制作黑噪音 -是的 [笑]
There is that concerto, isn’t that? That’s um…
不是有一曲协奏曲嘛 是那个 嗯
that piece of classical music, meant to be classical,
古典音乐一部分 其本身就古典
just like a time of 4′ 32″ or something,
就像4分32秒或者其他
which was just silence, just pure silence.
只是沉默 是那种单纯的沉默
That’s what it is.
那就是黑噪音
It’s called John Cage, isn’t it?
它是约翰凯奇的作品吗
There’s something ironic that like, you know, heavy metal people wear black,
有些讽刺 你知道 玩重金属的喜欢穿黑色
and yet black noise is silence.[laugh]
但黑噪音代表沉默[笑]
No, that’s good, yeah absolutely.
很好 绝对的
And that’s because we interact with it ultimately,
人类总是相互影响
because we interact with our environment.
因为我们与环境相互影响
And that doesn’t require consciousness,
但不是每个人都有这种意识
It’s just, you know, there’s just the very fact that these waves,
这些波的事实情况是
these quantum waves are getting scattered off of objects.
这些是被物体打散了的量子波

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视频概述

不同类型的噪音为什么以颜色命名,他们意味着什么?

听录译者

卡比

翻译译者

Wizard

审核员

审核员1024

视频来源

https://www.youtube.com/watch?v=2var6ewNEuc

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