Output signal to serial port

Hello everyone I am a PhD student
in neuroscience and I made a nice pseudo-VR experiment with tge 1.5.

I record electrical activity from subject at a sampling rate and I need the game to send out pulses
(called triggers in our jargon) whenever something important happens so that I know when I look
at the recorded data when something happend.

I impleneted this with a 30ms long .wav file that is 2d and preloaded but it turns out that
tge plays it a large jitter +-100 ms atleast.

I need to find a lower level output like turning on a bit from 0 to 1 in the serial port or something like that.
is there a way to do such a thing in tge?

thanks in advance!
Omri