Q:
Which sounds are reverted to pre-0.18?
A:
Base game - assembling machines, manual mining, inserters, & transport belts.
Bob - assembling machines, inserters, & transport belts.

Q:
What are the new laser sound effects?
A:
Base game & (optional) Bob - laser turrets (0.18, pre-0.18, new type 1 to 4: low humming, high-power, laser drill, & eye laser )