The musical term "sustain" means persistence.

the sustain parameter is the Sustain Time.

if you keep pressing a Decay on an electronic keyboard instrument, the sound will enter a relatively stable state after Attack and decline, and this state is sustainable.

Sustain Time is used to adjust how long the sound can last when you keep pressing the keys. Like the timbre of a drum, even if you hold down the keys, its sound will only appear for a while, so its duration time is relatively short;

Like a piano, when you hold down the keys, its sound will slowly weaken, so the piano timbre lasts for a long time; For the timbre of stringed instruments, as long as you keep pressing the keys, the sound will keep a constant volume and will not disappear, so its duration time is infinite.

Extended data:

The four parameters of the wave seal are Attack, Decay, Sustain and Release.

1. Attack parameter

If the value of Attack Time is larger, it means that the time between playing (pressing the key) and the maximum volume of the timbre will be longer, and the sound sounds like a feeling of getting up slowly; If the Attack Time value is smaller, it means that the time from playing (pressing the key) to the maximum volume will be shorter and the sound will sound more sonorous.

2. Decay parameter

The timbre characteristic of many traditional musical instruments is that when the sound reaches the maximum volume at the beginning of playing, it will immediately drop down again, that is, fade until the volume is stable. Decay Time is used to determine how fast this decay will be.

3. Sustain parameter

If you keep pressing a key on an electronic keyboard instrument, the sound will enter a relatively stable state after Attack and Decay, and this time is called Sustain.

4. The Release parameter

refers to how long the sound can last after you stop playing (release the keys). If the Release Time is long, even if you let go of the keys, you can still hear the sound gradually weakening.

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