噪 is 通常 描述 as ‘unwanted sound’ But 噪 声 can be very interesting too

制作 用 of 讨厌 Sounds
通常 we differentiate between 噪 and 樂/乐 However if any 声波 can be used to make a 作品 of 声波 底/基于 樂/乐 then why 不 embrace 噪 and 用 it as the 主要 ingredient in pieces?

As we discovered when exploring 音高 most 声 are actually on a 连续统一 between 噪 and 纯 音高

Fact
All 声 from the 自然 world will 包含 some 形（曲）式 of 噪

As composers 艺术家 and 音乐家 continued to 探索 声 they soon realised that to ignore 噪 声 意味 to miss out on some exciting 可能性

Why should we ignore or reject 噪 声 just because they are different?

P1-1 噪 Excerpt
A glitchy 轨 made of many different 噪 故障 回授（反馈） and other 'unwanted' 声 By Andrew Hill

Where do 噪 声 come from?
Some of the most common 噪 声 are Glitches 回授（反馈） and Hiss

噪 声 are often 生成 through a faulty 联系 error or by a malfunction But we can also 创作 them 故意

活动 – 噪 from a Faulty Connection
You can 创作 a ‘faulty connection’ 噪 声波 by plugging and un-plugging your 耳机

Put the 耳机 on then un-plug the jack from the socket As the jack plug moves out of the socket you should head a short crackling 故障 声波

Push the plug back into the socket and you should 听 another short 故障 声波 These 故障 声 are cause by the contacts on the plug moving against the contacts in the socket

When the plug is half in we make a 联系 but a faulty or bad one The 噪 comes from this fault

Headphone 故障 Sound
Here is a 錄/录 of the 种类 of glitches that you might 听 from a plug and socket

Fact – 故障 Sounds
故障 声 are 创作 because of the way that electricity can very quickly turn on and off

声 产生 in this way have the most sudden start and finish This makes them almost 独特 because it would be 不可能 for such 声 to 出现 naturally outside of an 电子 系统

活动 – 噪 from a Feedback
回授（反馈） occurs when you 创作 a 信号 循环 that feeds back into itself This 循环 continually adds to itself amplifying any 细节 into a wonderful screeching cacophony

回授（反馈） Sound
This is a 錄/录 of 电子 回授（反馈） As the 输入 控制 volume and equaliser 音 are changed so the 回授（反馈） 声波 evolves

创作 your own 回授（反馈） Loop

!!!TAKE CARE!!! 回授（反馈） can be very 响

It is very simple to 创作 a 回授（反馈） 循环 You simply connect the 输出 into the 输入

This can be done by pointing a 声筒（麦克风） at a 扬声器 as in the picture above or by plugging the 输出 cable from a 设备 back into the the 输入 of that same 设备

You can 用 any 设备 with an 扩器

If we connect cables then we won’t be able to 听 the 循环 because it will be entirely inside the 电子 系统 To 听 it we need to split the 循环 and 送 some of it to a 扬声器 so that we can 听 the 声波 we are 创作

If you have a small 混 desk you can 创作 a few of these simple loops and the 声波 quickly becomes more and more 复杂 as the different loops 交互

Fact
Electric guitars are also famous for their 回授（反馈） They 用 a 组合 of 电子 and 物理 中项

The guitar makes a 声波 and the 扩器 boosts it

This causes the 弦 on the guitar to 振动 and so more 声波 is 送 to be 扩音（放大） by the 扩器

The more 声波 that is 扩音（放大） then the more the 弦 vibrate… and so the 周期 goes on

Guitar Feedback
A short clip of guitar 回授（反馈）

Quiet Noise?
不 all 噪 声 need to be 响

噪 声 are often 联合 with 响度 because as ‘unwanted sounds’ we often wish they were quieter

But if we think of 噪 声 as being those with a noisy 质地（纹理、织体） then it becomes clear to see that we can have 噪 声 at any volume

Rickshaw by Dushume
This 声 quite different doesn't it? Can you 听 the different colours? The different pitches? The rhythms? 听 to it again and try to 探索 this world of 声波

What is noise? What is music?
Many 人 argue about 噪 樂/乐 It is very hard to 定义
What is noise? What is music?

We can 用 噪 to make 樂/乐 they often 声波 interesting 独特 and exciting