I have heard mention that people were surprised at how quiet their unit was, and I can agree when it is on and in standby, I would agree that is quiet, but when the cutting begins, it gets very loud. I perceive it to be as loud as the blower fan that came with my Chinese redsail clone last summer. So loud you can’t have a conversation at the other side of the room without raising your voice.
Is this a problem with the unit or if this is normal, how can I mitigate this loudness?
I don’t think a problem with the machine especially if you are in a small room. It’s definitely a third person in the conversation. @takitus recommends wrapping in insulation to cut down on sound reverb coming from hose.
It’s seems different people have different perceptions or the sound varies.
Wrap your vent tube with sound stifling insulation and make a sound chamber for the bottom of the unit:
Wow. I’ll say… the thing makes some noise when it’s in action. I’d say vacuum cleaner volume. Maybe a little less. I have a thin… accordion style separator (wouldn’t call it a door, it’s only thin vinyl). With that closed, I can hear that it’s running from 2 rooms away, but it’s no real noise nuisance. I wonder if you’re getting some reverberation from whatever support (table?) you’re using? That can even translate into reverberation in the floor. Or maybe your exhaust hose isn’t sealing well?
It’s a big room. @tbelhumer can attest the table is solid. The aluminum piping extends about a foot past the birch ply board duct taped to the window. I’ll try some cloth and or foam wrappings on the tube and let you guys know.
probably an overabundance of caution but if you use foam, make sure it’s flame-resistant. i mean nothing should happen in normal use but god forbid the laser gets going, then that connects near the walls…
Yeah, I guess perceived sound is very subjective. In my living room or bedroom I would be saying, “Wow, that’s loud”. In my basement studio or garage, I don’t give it a second thought. It seems standard vacuum cleaner loudness to me. Not going to watch TV but can have a normal conversation. Lots of different variables for different people, maybe carpeted floors, hardwood floors, lots of soft surfaces, hard surface table, distance from the walls, age of the user (i.e. frequency acuity). Powerful fans that fit in a small space.
Is the room itself hard floor or carpeted? That will make a pretty big impact on how loud the unit seems. A nice thick carpet is going to suck up a lot of sound so if you have hard floors, it might be time to decorate with a cool rug. 
The insulated duct flex could be used to enclose the 4" dryer vent flex to help dampen the vent noise.
It will be a bit tedious to snake the 4" dryer flex duct, but it will dampen the noise.
It is laminate flooring so… Not soft. Closer to hardwood floor than carpet. It’s at one end of the long living room.
Even a solid table can pass sound waves through it on to the floor.
things to try, or look at getting a small piece of acoustimac and have it between the table and the GF.
other things is something like this.
I have done a small paver stone under my 3D printer to help with the sound.
Him indoors has caught the Audible.com bug and can now be seen modeling the Bose noise cancelling bluetooth headphones a friend got him for his birthday almost all day long.
God I hate them!
Tapestries. You need tapestries.
Laser engraved tapestries.
Or use the 4" and just replace the existing hose.
I have several wall scrolls for various anime franchises. They are pretty thin. If tapestry is the way to go, I’ll be a bit disappointed, it’d be difficult to tastefully intermingle wall scrolls and tapestry together, so the scrolls will have to go. At least the wifey dear will be happy. 
I was just going to look for that…
i’ve been looking for an excuse