Air vents behind Access Cab seats / Road noise

A while ago I removed the rear seats in my 2003 Access Cab. I immediately noticed a lot more noise, which makes sense without the mass of the cushions to block and absorb it. But it sounded to me like there was also a hole to the outside - like a window was open or something - and that didn't seem desirable.

I was wondering (in another thread) if there was some sort of gap...for drainage or something. Somebody else suggested it might be from the bolt holes for the seats, which might just go through to the outside.



I finally had a chance to poke around some, and I think I found the culprit: an air vent?

So my questions are:

1) Is this indeed just a passive air vent? The cover (which I am holding) seems to be an ambidextrous part which, on the driver's side, has a punch out directing air (?) towards the center of the cabin. I assume, but have not actually looked, that the cover on the passenger side has the other side of the cover punched out.

2) More importantly - HERE IS MY MAIN QUESTION for those just scanning - is there any reason I can't block it to reduce noise?

Assuming that engineers (and bean counters) don't put in anything that isn't necessary, I'm cautious, but if it is a vent purely for the comfort of my non-existent access cab passengers, then I'm going to cover it with deadening mat.

On a funnier / dumber note, I noticed cold air coming in from the driver side footwell, even with the heat turned up. I was worried I had some leak or something. Finally crawled under to look, found the crotch vent. Nice!

 

1) I allows your heating and A/C to work properly by balancing the air pressure.

2) See #1

 

Nicely done. Ok, thanks!

 

The technical term is 'exhauster'

https://jalopnik.com/heres-what-those-rubber-flaps-are-hidden-behind-your-re-1828016409

 

Thank you both very much - glad I asked, and happy to have learned something.

So it seems like I should be able to leave the vent, the shroud, and the cover in place, but perhaps hang some sound deadening mat over it - loosely, not sealed or blocking anything - and still be ok. The seats served to muffle the road and air noise, so I should be able to take some steps to mitigate them myself.

 

The Nomadicfrog still has his tundra? Nice! I remember you from years ago on TS. You had a personal blog site too I believe right?

When my back seat was out I had cut up some sponge-like filter material and slid it into the rectangular port holes. It helped to muffle the wind noise but allowed the flaps inside of there to operate. If you watch the flaps and have somebody open and shit the door with windows up you'll see the operation.

 

I am confused, but I think we both are. Yes, this Nomadicfrog still has his Tundra, but I've only had it about 11 months. I also have a personal blog site (http://journal.nomadicfrog.com). Not sure what TS you might be referring to, but it sounds like you mean a different Nomadicfrog with a different Tundra, which is in and of itself slightly weird!

 

I drink a bit. could be

 

Update: I finally got a chance to do some sound dampening, and here are some representative photos. This is the first time I've done this sort of thing, so it's not all that great, but it did seem to help some.

I removed the plastic shroud over the exhausters so I could get the sound mat right in around them.



One sheet of Noico fits nicely from top to bottom.


I put two sheets on the main back, then cut a sheet a bit shorter, stripped the backing paper off just the top and bottom, and created a tunnel / baffle over the exhauster. (The plastic cover shroud is back on too underneath there.)



This does seem to quiet the wind / road noise coming in through the exhausters now that my access cab seats are out. And the AC still seems to work ok and the windshield doesn't pop out when I close the doors.



It's hard to see, but that bulge in the middle there is open on both ends to allow airflow.

...but I do wonder about the difference between sound / vibration dampening, which is what these butyl (?) mats do, versus sound absorbing, which is what I really want to accomplish and which would require...foam mats or something like those greenish-orange things Toyota put back there?

 

Go look at what I did yesterday to achieve both. Combo’d the butyl with some factory OEM matting.

 

I know that feeling...