Check out 3rd post on this thread, https://pinside.com/pinball/forum/topic/ij-sound-all-of-a-sudden-gets-really-loud

Most of the time this is wiring or ribbon cable connections, not ROMS, unless there was some type of static discharge if you were not grounded, and one got damaged.
You are problem going to waste money, so let me explain.

The most common sound chksum error problem is the ribbon cable connection that goes from the CPU to the sound board.
I just brought my White Water "online" after it had been in storage for 10 years, and this same problem occurred and it has occurred in other games in my past, if in extended storage.
DMD had similiar problems with vertical lines due to other ribbon cables.
Bottom line is you may need to physical pull the connectors OFF and reseat them, not just push them in.
Oxidation to connectors over time causes loss of electrical connection.
If this STILL does not work, get a new set of ribbon cables and prepare to do electrical test connections, BEFORE Eprom replacement.

Could equally well be an EEPROM. Wouldn't the sound board give an error tone as well?

Good sound, no more checksum error?

Keep in mind oxidation can occur on the legs of the Eproms as well for the future.
It is possible to clean/retest and not replace them, but of course, your solution is simpler.
Smoky environments KILL boards early too, because tar like residue can actually build up on boards and Eprom legs, reducing their electrical connectivity.
It sticks to them like magnets.