Sony NEX-5N External Mic "Rumble" test (w/ ext mic gain test)

VIDEO#3 Sony NEX-5n with and without External Mic ECM-SST1.
This is video #3 with ext mic on while panning in a quiet bathroom. In an effort to test if there is an auto gain control, I talk gibberish through the panning test to see if the rumble would dissipate to compensate for my voice...it doesn't appear to.
As mentioned in the earlier videos...Notice the rumble, as if there's a light breeze in the room. One of the reasons I got this mic is ironically to minimize wind noise. The audio is actually quieter without the external mic (see video #2).
I tried fiddling with the two audio settings (movie audio On/off and Wind noise reduction on/off but nothing made a difference.
Is it just me hearing this?
Anyone else experience this or have advice to offer?

[@Vicarium]

Actually, I used my headphones and could hear the rumble...only just though. For me the external mic is a way to capture video with the annoying click my 5N makes *and* eliminates all the on and near camera noises (breathing, hand movements, strap lugs clicking etc).

[@kloakan1]

i can hear it very well.. its worser than internal mic.. actually internal mic isnt that bad because theres no hiss at all.. i ll leave my zoom h1 and use vegas t osync my videos with sound.. please write me if you left your mic or sell it.. :) thanks

[@Vicarium]

I *really* listened to this...had my speakers up on the highest setting with my ear against the mesh and I simply couldn't hear anything. Try the same test with the external mic off the camera...the built in mics are *so* sensitive, that they are all but unusable IMO.