I agree, sounds like a switch matrix issue. Both of the sounds you are hearing indicate a closure of switch 44 and switch 14 (YELLOW) respectively, both of these switches are on row 4 which is half of your phantom switch issues pre-identified. Since this also seems to occur when a ball is in the shooter lane and/or there are less balls in the ball trough (GREEN), this gives you additional information to help you test for phantom switch closures.
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