There’s a piezo spring on the module of old G-Shocks that makes contact with the case, where the speakers are housed, to make the watch beep.
Unfortunately, the spring is in direct contact with the back of the crystal, which holds the speakers, and over time it can wear a hole in the screen decal.
A common preventative measure is to use a spot of conductive carbon tape designed for electron microscopes. It will weaken the beep but prevent a hole from forming in the crystal’s graphic.
This account is verified. WatchCrunch has confirmed that this account is the authentic presence for this person or brand.