Hi.
Often ground just means connecting to the battery's ground (0). That would be the circuit ground.
The audio ground would be the outer shield of an audio cable. In most audio cables, you just have 2 wires per channel (left & right mostly) and that should be it. Note that in many (most?) designs, audio ground is more or less connected to the circuits ground.
The "chassis ground" would be the box you're building your project into. For a computer, it would simply mean connecting the cable to the computer chassi.
Technical ground I dunno... if you try to look into the schematics description (could state something like "R2 is connected to the technical ground"), you could prob. check up R2 in the design and see where it is connected...
I don't have any idea if this helped you some, but I hope so.
//Albert "thec" Sandberg