I would doubt the power going out directly caused the noise you are hearing. Possibly indirectly as in my experience with motors / impellers they are usually running fine and it's not until you turn them off say for maintenance and plug them back in you get a rattle. Gunk shifts just enough to throw it out of wack. Typically a good cleaning and back in business.
A lot of things have to go right (wrong) for a surge to nuke something. And usually when it does the device is toast. The first to go are usually devices at the end of the 'line'. And if just that device gets fried chances are it wasn't meant to be.
It takes quite the surge to destroy devices, and if you should experience that your pump wouldn't be the only casualty.
Redundancy is key for protection. Even without properly grounded outlets a quality surge protector will do the trick for a minor surge. For more piece of mind I installed a whole panel surge protector. Only 60 - 120 bucks depending on panel brand. Cool thing is it's just 2 poles, you can get in 15 or 20 amps, AND you can also use those breakers. Neat.
Now will it thwart a Mount Olympus Zeus attack? No. But better than nothing.