I can confirm that during Arcane Revelation, sometimes the static electric sound does not play. Although there have been cases where it only affects one player, it usually affects the entire party. It's a rare bug but it does happen and it often causes a full wipe.

The problem with this is that most players use the audio que to do the mechanic and rely completely upon it. It's the most consistent way to do the mechanic.

Technically, you can look at the visual ques, but I found that doing this caused me to get the timing wrong. Listening to the audio que allows me to focus on attacking as well. Most other players rely completely upon the audio during the intermission phase, because looking at the train going around in the distance while attacking is a lot for them.