What are the relative internal noise levels in various aircraft? What are the relative noise levels in various aviation scenarios for observers seated inside an aircraft? I'm sure the specifics depend on model but I'm curious if any general trends can be drawn that are model agnostic.

e.g. Let's consider the following cases for a start:


Jet aircraft e.g. 747
Jet aircraft gliding with all engines out
Helicopter
Glider
Jet aircraft with noise insulation removed
Piston driven prop. aircraft


We could rate on an arbitrary 1 to 100 (noisiest) scale. Even better, in case data is available, I'd love to see the dB values. (@vortaq7's comment below)

I suppose speed will matter so we can probably use their typical cruise conditions for each case?

One motivation is to tease apart contributions from engine vs aerodynamic noise. Another is to quantify the effectiveness of sound insulation. 

I suppose most of us never get a chance to really hear an all engines out jet nor to fly in a jet with no sound proofing. 

PS. This question was motivated by some comments here:

What are these green &quot;bags&quot; on the SSJ100?
Let's start with the items for which hard data is easily available: 


This FAA chart gives relatively average noise levels for passenger jets, GA turbine aircraft, and helicopters. In addition, this chart should start to give an idea of how much noise is generated aerodynamically in aircraft: 


While this is older ground data and not cabin data, it still serves to show that the contribution of aerodynamic noise to total nose levels is not insignificant. 

Based on this, I would say that a likely ranking of these environments, from loudest to quietest, is:

1/2: Helicopters and uninsulated jets. In both cases, the close proximity to large, powerful engines leads to extremely high noise levels. 

3: General Aviation piston-engined planes. Again, these generally have little insulation,but smaller engines generating somewhat less sound. 

4: Passenger jet cabin. Protective insulation reduces sound, but actual noise levels vary based on seat position. 

5: Passenger jet cabin, gliding. As seen in the second chart, aerodynamic noise still contributes to a relatively loud environment.

6: Gliders. Slower speeds and cleaner aerodynamic profiles reduce aerodynamic noise, leading to a much quieter ride.