Using a pc to capture sound and trigger a flash.

Since i don't have any way of triggering a flash with sound and i would like to try that type of photography is there anyway i could use the headphone out? digital out or something from a PC to set off a radio trigger?

I tried just plugging the radio trigger into the headphone out but im guessing it doesn't have the power on its own? (Sound is an electronic signal at that stage).

Has anyone else tried this or had any luck?, guess i could hit up fleebay and look for something on there but was hoping I could do it with the things i have as its mostly just for some fun.
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