When someone upstairs jumps on the floor, the air in the empty cavity between the floors (inside the ceiling) is going to vibrate and create sound - no carpet is going to stop that.

@Timothy VanceThere is acoustical rated drywall that is ridiculously expensive but it does not do much for vibration.

Might help to have foam weather stripping all around the door to help insulate from vibrations, but it will never be perfect.I know you can buy sound proof doors, but they cost as much as a car.

If you are still interested in how I went about the research and where I am at in terms of becoming a real estate investor, please read on.First of all, for those who don’t know who I am, I would like to give you my current situation regarding the real estate investing journey.Current situationI am currently working as a full-time engineer, and in fact, I am typing this in a hotel room before attending a shock and vibration test for one of the suppliers in Long Island, NY (sorry this is not relevant information for real estate).

Happened at 145am appx - I was just heading to bed (I'm a night owl) and taking a shower on our lower level - shower door started shaking pretty violently up and down and you could see the walls vibrating a bit.  

Contract it out.If the floors are not too bad rent the industrial size vibrating floor sanders.

I believe the current fix is to crimp on pigtails to all ends and replace the old switches and outlets... varies but think it is running $2500 to $5500 per house to correct... aluminum vibrates when it gets a little loose causing resistance and then heat.. hence the problem.lots of homes have black pipe or steel pipe water lines used a lot in older homes and it is OK but it rusts inside and then as the corrosion continues the pipe gets weak at the joints mostly and often can fill up  and restrict water flowall this being said I have seen extension cords run behind finished walls,  I have heard people removing 40amp breakers and replacing with 50amp breakers because the 40amp keeps tripping.  

Besides a contractor they do make machine, floor stripper, that vibrate and will rip it up.

I hear music from the kitchen so loud it vibrates everything in my room.

If I was their teacher, I would have passed them on their ingenuity for problems solving.Cliff notes:  They made pens that could transmit to another pen a vibration.