Hi.
I had a little question. Am I allowed to use a sound samples from the Fallout (like 'talking heads' voices) in a non-commercial music track which does not brings me any profit? This will be the usual tribute to the Fallout series.

As a general rule of thumb, no one is going to come after you for copyright infringment unless you ARE making money. I wouldn't worry about it too much.
What are you working on?

I'm working on few tracks between industrial / dark electro / noise / harsh / hardstyle genres.
First, in poor quality, not 100% finished (not all effects has been applied, no mastering etc.), can be heard there - http://www.youtube.com/watch?v=CAvVH5E9Gtk

"MUTANTS!"

Cool. Keep us updated.

If its the music you're planning to use, I'd recommend asking the Author directly:
http://auralnetwork.com/releases

As for the remaining sound. Yes, it is copyrighted. Who you'd need to ask is a complicated question, probably best directed at both Interplay and Bethesda. I'd send an email to them both.

In both causes, Beth and Interplay, the only e-mails i can find are for customer service and game technical support so I don't think it is the best way to contact them. Could you help me finding the proper e-mail?

You're right in thinking both of those addresses are probably not going to get you an answer, at least not quickly.

Coporate office is probably the way to go... For bethesda is probably best to contact their Parent corp, Zenimax who have a general enquiries form:
http://www.zenimax.com/contact_email.php

Interplay don't seem to have a catch all general enquries address, Investor Relations is probably going to be the closest you'll find:
http://www.interplay.com/investors/investor_contact.php
Although PMing Chris Taylor on the Interplay Forums may also get you the response you're looking for.

Interplay doesn't own any of the existing single player IP anymore... that would include audio and music, so I doubt they'll have much of an answer for you.

As for getting through to someone with an answer at Bethesda or Zenimax, you might try PMing http://www.gamesas.com/index.php?/user/365941-gstaff/, here, I would think they'd be able to point you in the right direction.

They may not own the "universe" but they might own portions of the games... My understanding is that stuff is really complicated. Since it takes no extra bother to send another email, it doesnt hurt to be safe rather than sorry.

No.... IP is intellectual property... that would cover all created product (concept art, coding, engine, finished artwork, voice-over, music, etc) as well as 'conceived ideas', as in Title, setting, brands (like Nuka-Cola or Vault-Tec) etc....
This is part of the reason why Interplay is having to start from the ground up with FOOL (and perhaps a reason why the project could fail). Not to get too off-topic, anyways.... You're right, it won't hurt to contact Interplay, but I wouldn't expect much of an answer.

In the end, tribute projects that are not intended for personal gain, are free game and fall into the same category as Fan Fiction. Fox won't sue you over a fan-fic of Family Guy (unless you try to sell it), and Bethesda/Zenimax won't sue you for a song that uses some soundclips (unless you try to sell it).