Tiny particles of 声波 small chunks that fall between the gaps but which can join together to 创作 large sounding 对象

Micro- to Macro- sounds
When we bring micro-sounds together we 创作 macro-sounds larger 结构 of 声波 These macro-sounds can themselves be built into larger 结构

Building 宏观 声 in this way from individual grains upwards gives the 作曲家 great 控制 over the 终 结果 And the 过程 is greatly helped by 算機/计算机 and 电子 技术

作曲 Tip
The most 重要 过程 for this 樂/乐 are

加 and 减 合成
Filters
and 粒 Synthesis

Grains of Sound
想像 the grains of sand on a beach Each of them is very small but together they can 形（曲）式 sand castles and even mighty sand dunes

Grains of 声波 are exactly the same They are tiny particles of 声波 that when 合并 together can 创作 fantastic new 形状 and 结构

It’s often difficult for us to 听 individual grains on their own because they are so small

Masses of Sound
There are two 主要 种类 of 声波 masses

Fused blocks of 频率 – 创作 by very closely packed 音高 of 声波

Cloud 质地（纹理、织体） – made from a mass of individual grains which swarm and 流 together

In both cases the 作曲家 creates subtle 变形 by altering the balance within the 声 over 时间

Blocks of Sound

Within blocks of 声波 the 作曲家 will subtly add or subtract 音高 from within the 声波 mass

Listening
Examples of such 作品 include Györgi Ligeti’s Atmosphères or his 作品 Volumina

Cloud textures

Clouds of 声波 are structured differently These take the 形（曲）式 of more fluid masses of 声波 in which the individual grains of 声 flock and swarm each 流动 自由 but within a certain trajectory

Listening
Examples of such 作品 include Xenakis’ 作品 實/具体 PH or Bernard Parmégiani’s De Natura Sonorum

In these 作品 there may be many individual 声波 clouds which merge together or divide from one another

The 属性 of swarming clouds of 声波 allow them to merge seamlessly together with a simple cross 淡化

Beyond the Limits of our Hearing
When 声 are shorter than 1/10th of a second 10ms we can no longer 听 them as individual 声

These tiny chunks of 声波 are beyond the limits of our 听觉 So we don’t 听 them begin or end

Fact
阀值 is a 术语 used to 描述 the limits of our 听觉 If a group of 声 are shorter than our 时间 阀值 for 听觉 we will 不 听 them 个别

The same is true for 声 that are very close together in 音高 Beyond the 音高 阀值 we are unable to 听 individual 音高

This property allows us to merge 声 together in the 结构 of seamless masses of 声波

Reference
罗兹 C 2004 微声 MIT Press