Soldato
I did notice the crowd noise seemed more noticeable on the world feed for this race. What makes you think it was faked?
A few things. Firstly, this is Malaysia. There was hardly anyone at the race - even the main grandstand was only half full. Secondly, this is Malaysia - not exactly known for rapturous applause and cheering at any of the previous 17 races.
Also, the noise was only from certain cameras, and often this was at a point on the circuit where there were no stands full of supporters, or even any stands. And often the noise was at a point where there was nothing going on other than a car driving past.
You can hear the Silverstone roar, and it was great this year for both Hamilton and Vettel for different reasons. That was genuine. But the sound in Malaysia was really artificial. I've no idea if it was canned or broadcast sound from a different part of the circuit, but it was far from natural.