From memory there's something in the code to stop sounds when firing a momentary coil. Actually it's not 100% perfect because on odd occasions my games will play a spurious tone when activating a solenoid - usually a drop target reset.

Communications of the -32/-50 sound board and -51 sound board are totally different.
The -51 sound board has its own processor. It receives a sound command from the MPU board and does the rest.
The processor for the -32/-50 sound board is actually the main MPU boards CPU - i.e. it's burdened with the task of controlling the sound board. Data sent to the sound board selects what tone (frequency) to play. Game code has tables for the sounds and how long they play. There are about 30 selectable audible tones.

I have to look up my notes if you want more details but I've got to head off for the day.
Maybe others can chime in

Download the datasheet for the 4042 and look at the truth table

There might be some useful info in the thread more so as it progressed.
https://pinside.com/pinball/forum/topic/bally-paragon-generating-extra-tone-sequences

No tones should play when solenoids are being activated. The pin headers on these sound boards commonly crack, might want to take a close look. May be an issue with sound address E.

Note from memory there's one or two very high frequencies generated by the sound board that are inaudible to humans - they are effectively one way the board is made silent.