From the web........
"Beware the politics of F1, they can be found here too. There are two institutions that run F1, the rules body called the FIA, and the commercial rights holder FOM. The FIA has decided to make F1 ultra relevant to the politics of the green movement, which is now infesting most world governments. So we get smaller engines and much less fuel burn along with the supremely muffling effects of a turbo sitting right in front of the exhaust.

The FOM hates this new silent engine and it seems, has asked TV broadcasters to lower the volume of the natural sound of the cars during the race to make their point. I guess FOM thinks this will force the FIA to change their engine rules, probably wont happen, but its funny to watch the game between the FIA and FOM play out.

In the video you show, which was taken by fan, you can tell even this video has been played with, there is the sound of a track announcer in both vids, that announcer volume is much lower in the second clip then in the first. Everyone is getting in on the action. I too hate the new sound, but let the FIA stab themselves, its all a big joke, I'll get my entertainment any way I can."

Hmm. A billion of factors can make the noise different (microphone, camera (soundfiltres, eg. highpass of lowpass filtre), wind, temperature etc. etc.).
Was it recorded with the same camera?
Anyway, a lot o different in this video.

Nobody wearing earprotection in the second part of the video?. The cars don't sound right.

Forget the sound. Wasn't there a marked difference in speed. Much slower in 2014?

the guy with the red cap is wearing ear plugs in the 2nd vid @0:39

#5 that's because he's sitting next to his wife

Dyson makes Formular 1 engines now.....

It's not just the volume but the tone is way different. 2013 has that howl we got used to from the good old days of the V10s & V12s. While 2014 sounds like a lawnmower. In any case, I haven't watched a full race for 7-8 years, because of all the politics and complicated rule changes. I even gave away my corporate tickets I was gifted the last 2 years (AUH), to friends, nephews, and inlaws.

how to get this sport even more boring ......

Is this some kind of joke?

indeed, all air forces around world, switched to new fuel, usually blue colored lately.

#11 The US is only just testing,not switched, to alcohol based bio-fuel.

Believe it or not, I actually like the new sound... mostly because I hated the one million RPM ear-piercing sound of the NA V8 (even though I am a sucker for muscle V8 cars). Watching an F1 race was as much fun noise-wise as watching a room full of crying babies.
Obviously the more heat energy is converted into kinetic/electric energy, the less sound you will get.
This is literally the first time in two decades that I'm excited for F1 and watched a full race. Loving the new dynamics and challenges these new regulations bring to the table. Looking forward to Malaysia.

The new sound is because now they are allowed to use motors with turbo

I don't care how GREEN or Politically Correct the cars are now.......they SOUND CRAP!

Are we watching the F1 races to watch a race or to listen the sound of the engines. If for to listen the sound of the engines, then why a lot of people wearing ear protection. The aim of F1 is get people to produce powerful engines with less fuel usage. The new trend in the world is GREEN. Everybody is trying to produce green products. In this sense I support FIA. I think that it is not far away that we would see electrical F1 cars with no engine sound.

#10 Kind of like this one?

http://www.youtube.com/watch?v=CjqhmhObCMo