What does "Ka-Ching" mean?

[Jack Sparrow]

yesterday I listened to the song Ka-Ching of SHANIA TWAIN but I don't know what does "Ka-ching" mean. I used my dictionary to look this word up but it didn't appear in my dictionary. Then, can anyone tell me what it means ?? Thanks a lot.

[Mister Micawber]

It usually means the sound of a cash register being rung up: money coming in. However, with no further context, I cannot be sure.
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Native English teacher at Mister Micawber's