Clicking on central horizontal line generates blue ball

[Ecaroh]

This wasn't the case in Amadeus II: if I happen to click exactly at the central horizontal line in the sound window, the line dividing left and right channels, with the cursor now becoming an index finger, I place a blue ball at that point. What is the ball? Is there a way to get rid of it without clicking "Z" for undo? I'm generating a lot of these balls as I train myself to remember to click somewhere else. --Thanks.

[Ecaroh]

Learned more about this ("add volume") here:

viewtopic.php?t=1529

but still curious exactly what it does. Added volume -- how much? And to what? I have a few of these inadvertently placed in edited files.

TIA.

[Martin Hairer]

The control points you add by clicking on that blue line allow you to adjust the volume envelope of the sound. If you have no use for it, you can hide it by choosing View -> Show Envelope For -> None.