Why is it that when you speed up audio to make it really fast, then slow it down to normal, it makes the audio grainy?

Hold on, I thought the pitch effect increased the speed, but where do you mean exactly?

medians wrote:

Hold on, I thought the pitch effect increased the speed, but where do you mean exactly?

The sound editor.

INSERT-USER_NAME wrote:

medians wrote:

Hold on, I thought the pitch effect increased the speed, but where do you mean exactly?

The sound editor.

wait what am I getting bamboozled again for a second my brain reverted to volume because I thought that there were no speed tools
Edit:

yea i am

ARandomNumberIs7482 wrote:

grainy

This happens whenever you edit the audio in a Scratch project. Why? I don't know. But speeding up the sound and then slowing it down, for example, counts as an edit.

This happens because scratch lowers the bitrate to speed up the sound. When you slow it down again after speeding it up a lot, there's very little bitrate left and the audio becomes “grainy”.

-Valtren- wrote:

This happens because scratch lowers the bitrate to speed up the sound. When you slow it down again after speeding it up a lot, there's very little bitrate left and the audio becomes “grainy”.

So it's a technique to save bitrate then?

ARandomNumberIs7482 wrote:

-Valtren- wrote:

This happens because scratch lowers the bitrate to speed up the sound. When you slow it down again after speeding it up a lot, there's very little bitrate left and the audio becomes “grainy”.

So it's a technique to save bitrate then?

You could press the undo button instead of slowing it back down.

This is because slowing down a sound does not “reconstruct” any audio samples; it just interpolates them, kind of like how you can't scale an image down and back up and get the original.

It's because when you speed up a sound, detail is lost, and when you slow it down again the detail is still lost.
If you have a bitmap image in the costume editor, and you make it smaller using the select tool and then make it bigger again, the image will look worse, for the same reason.