You could do a manual push mower! I’ve been looking to get one, I hear they’re much better for your lawn health and certainly help with getting a workout of it.
60dB is about the noise level of a household dishwasher. I think I could break that noise ordinance just taking out the trash, rolling the big plastic wheelybin the town issued me down my driveway to the street.
Incidentally I'm stealing the term "wheelybin" from the British. I'm willing to render it "wheelycan" to localize it to the New World if need be.