FNIRSi GC-01 Geiger Counter MOD to add Click Click Click.

From watching a YouTube video, I found an interesting concept.
The clip used a capacitor to bias the original BJT on the board (Y1 or SS8085).
This approach is correct for coupling and blocking DC. The destination is a speaker, not a buzzer,
so there’s no internal frequency component.
However, due to the BJT requiring current for biasing, the resulting sound is relatively quiet.

In another clip, a resistor was used instead of a capacitor, similar to directly supplying DC to the speaker. The current was divided by a resistor then even less.

Therefore, choosing an FET is a good option. FETs require biasing with voltage. And positioned at pin 50 of the chip, to drives the LED has sufficient voltage.