I doubt this answer helps, but I find that most treadmill motors are pretty quiet. It's the footfalls as a person runs that's the most disruptive noise. The motor is almost a white noise in the background. That said, I have a Precor 223 and find it very quiet.

I replaced my treadmill with a Landice. It is pretty quiet....and it has a lifetime warranty on all parts....including wearable parts.

Do you need to be the original owner?

I'm a new father (3.5mo old son), so here's my n=1 experience:

My short answer is that I have a Sole F80. My son has slept in a rocker next to the treadmill for many runs (some 2hrs+) so far and he hardly wakes up at all, in fact these have been some of his longest naps to date. My wife can sleep through the noise and our bedroom is right above the treadmill. Granted, I don't have to worry about other kids waking up or anything, so it's only wife that I have to be concerned about. But, my take is that he loves it because it's dark, he's swaddled, rocking, white noise (fans), and rhythmic sounds from the treadmill. So, that hits 3 of the 5 S's (swing, shush, swaddle) and he falls asleep quickly.

So, I'm not entirely certain that the noise of the treadmill matters much.

Also run on an F80. The right mat/padding underneath makes a big difference as well.

Maybe a fan in bedrooms for white noise to drown out treadmill?

Depending on where the treadmill is located, but I greatly reduced the noise by packing my basement ceiling with as much insulation as possible. Then sheet rocked it. We used to hear the treadmill on the 2nd floor of the house now I can barely hear it on the first floor.

As others said its the foot pounding that makes it loud, then add up cranking the TV volume. What I did for my TV is I bought a bluetooth transmitter with bluetooth headphones, works great.

Great idea!

Do you have dedicated circuit? I have garage that I want to put a treadmill in, but all outlets are gfci and brochures warn against using gfci (trips a lot) outlets with treadmill.

Do you or others have opinion on comparability issue? Thanks

Sort of, I completely finished the basement so when I did that room I put all of the outlets on their own dedicated ACFI 20amp circuit. With the TV, fan and treadmill I have not had any issues.

I'm no electrician (but I did my own wiring for this project), I can see a gfci tripping a lot but not completely sure.

Sorta, cost me $20k and several hundred hours of manual labor. As I said in the other post, ended up finishing the whole basement.