The sounds of footsteps, talking, gunfire, and general environment sounds will not stay synced with the video. It does catch up after a while.
I have 2gigs of ram but I do not have a sound card installed. No other games give me this type of trouble.
I'm wondering if more ram or a sound card is the best fix...

same issue...in FO3 i had to do some tweaking to get radio to work, now the only way to avoid the problems listed above is to leave the radio on...annoying.

I had no problems at all with FO3, always ran smooth and no crashing. New Vegas crashes a good bit plus the sound issues. I've added 2 gigs more of RAM and the problem is not as bad but it is still there.
I guess I'm going to install a sound card and see what happens. I wish Bethesda would have kept Obsidian out of this game as well.

I too have the same problem I believe.
Voice doesn't sync worth a flip and so on...
I thou have found a solution somewhat if crude in nature

Start the game
After its loaded up Alt+Tab out
Bring up the Task Manager
Find and Right-click FalloutNV
Go down to Set Priorities
Select High
Now Alt+Tab back into the game
That should Fix it

Also Plisskin: Obsidian Had nothing to do with the affairs of the current state of the software. That is entirely Bethesda. Been that way ever cence Fallout 3 thou I hadn't had it this bad.
Obsidian has came back from the original Fallout Series with help on storyline visuals and oddities such as the Indiana Jones cameo and the other related References the original series was also known for having.
To wrap things up... Don't blame them for an already unstable software

Wow - sound sync issue?
First I've heard of this one, man, now I've heard it all.
Well the two problem areas...
#1 the testers were not hooking up to the Steam Cloud
#2 they were testing on a limited number/type of machine configurations
...can bite them (and they are, I believe, sporting bite marks).
So many problems!
I had issues (bad, pissed me off) but they're fixed now and I can try to help others.
Okay, I have onboard sound too, kinda crappy but it uses the basic Windows/DirectX stuff so it's very compatible.
But as an Oblivion and FO3 player, I remember Tweakguides.com guy Koroush Ghazi posting pages and pages of all the .ini file workings, and one of the tips was to increase the audio cache size (which I did).
But apart from that there's really nothing you can do, is there?
I mean, maybe a genuine Creative SoundBlaster card would give you power - by giving you software!
But in my experience the software can be obtrusive and is unneccessary.
Anyway to get it to work
I believe 100% workloads are being experienced on your CPU and/or vidcard and/or harddisks.
Maybe all three. (I'd need a DXdiag from you if you want recommendations.)
In that scenario, with memory, CPU, video and storage bottlenecks, the audio could be getting corked-up and dropping frames.
In theory.
I'd say it's probably very CPU-dependant, but do any of you guys with this issue have a killer CPU?
You know, if buying a SoundBlaster can actually help your rig by taking load off your CPU, I say go for it.
Actually it's much better quality hardware than the onboard stuff (most of which isn't actually hardware anyway) for only $39 bucks or whatever.
I think I'm going to do that myself!
My onboard audio has been giving me trouble, but no sync issues as you report.
Anyway, more-better-faster and see if you can fix it up.
If this thread gets noticed, everyone with this problem will flock here and there will be a fix...
Go to TweakGuides and read up on Oblivion and Fallout3, where I believe he talks about your issues.
Good luck, and keep us posted.
Regards