#### Grain Delay Origins

Grain delay effect draws its roots from granular synthesis. It all started in 1946 when a physicist called Dennis Gabor published his work about applying quantum physics methods to the sound signal. With this work, he came up with the system that uses grain system to reproduce a sound.

In later years Greek-French composer and musical theorist Iannis Xenakis got in touch with Gabor`s work. He used it to create a musical application based on the principle. His first works involved granular synthesis created by splicing magnetic tape into very small segments, rearranging those segments and taping the new string of the segments together.

Shortly after that, inspired by Xenakis works, Curtis Roads began experimenting with this idea on a computer. He was the first person to implement granular sound processing in the digital domain.

Following that in the mid-1980’s a Canadian composer named Barry Truax began developing a way to create a granular synthesis in real time. Since then granular synthesis has become available to a growing number of musicians.

#### Granular Synthesis

Granular synthesis is a type of basic sound synthesis method that operates on the microsecond time scale. It works on the same principle as sampling. However, the samples are not played back conventionally but are instead split into small pieces of around 1 to 50 ms. These small pieces are called grains. Multiple grains may be layered on top of each other. They may play at different speeds, phases, volume, and frequency, among other parameters.

#### Grain Size

The grain size is usually presented in in Hertz (Hz) using the Frequency control. You can think of as grains per second — higher frequencies mean larger and lower frequencies smaller grains. You can calculate the grain size in fractions of a beat at your song’s tempo by dividing the tempo by 60 times the frequency. For example, at a tempo of 120 bpm, a frequency of 4Hz (four grains per second) captures a half-beat (an eighth-note) per grain. But you don’t need to be overly concerned with grain size. Its practical significance is that larger grains (lower frequencies) are more stable when you use feedback, pitch-shifting or jittering with the Spray and Random Pitch controls.

#### Conclusion

Grain delays slice the input audio into extremely short segments, then delay each slice by a slightly different time. Most granular delays also incorporate pitch-shifters, which allow them to change the pitch of each slice. Granular delays are the most complex delay plug-ins and can warp and mangle audio into a completely different sound. In the recent times, there are many grain delay effects available on the market. Some of them contain simple control parameters while others are very complex.