I'm also one of the Delphi Users (we're rare but we're ther)
As i experienced it, it's realy hard to write some good vis plugs starting up without any knowledge. Maybe you should try to use your Soundcard's MixRecord function. Record the sound and get the signal into your prog directly. But maybe that's even more difficult, i never tried such things out...
By the Way, doyou have any Drag&Drop experiences? I've almost completed a hotkey tool (click here for info)
but i'm still struggling with adding drag&drop.
Hope you'll succeed