Geiger counter DIY electronics question...

[Frangible]

I have a device that converts an analog "beep" into a digital signal and outputs it to an RS232 port for use with a PC, designed to work with geiger counters. It plugs into a geiger counter's headphone jack. I though it would be cool to look at count trends in my house. (yeah, I'm a geek)

My geiger counter doesn't have a headphone jack but rather a small piezo speaker.

Can I directly wire the speaker output to a headphone jack? Do I need any resistors/diodes etc?

Thanks.