how to send a sound in real time?

Hello,
i have a problem:
i'ld like to send a beep as long as i'm pressing a key in Tk (with bind 
event)
and i can't...
i've tryed with Audio::Play... but it's impossible to stop the sound 
before the end of data called...
i've tryed to with threads and DESTROY methode of Audio::Play...

i want to do this operation to build a morse teacher program (and so to 
learn perl).
if someone have an idea, it'll be fun to write me the answer... lol

thanks a lot for your answer.

jerome