How Salah is growing into role as one of world's biggest stars
So much can be gleaned from the noises of a crowd, even in the moments that don't really matter.
Whenever Liverpool play, the last meaningful thing Jurgen Klopp instructs his team to do in the warm-up involves shooting practice.
Six players stand in three pockets of two on the edge of the box and have crosses served into them from wide areas.
The idea is to finish one delivery with the left foot, another with the right and then make the last a header.
For the forwards and midfielders, it is designed to build confidence - to have a goal fresh in the memory before it all really starts.
Though his influence was vast, Mohamed Salah ultimately did not score on Sunday. Yet as Liverpool prepared, it had seemed Cardiff's supporters were watching him the closest as he wrapped one shot past Simon Mignolet with disguise by appearing to send him one way before going the other.
He followed that up by larruping two more rounds beyond the reach of the Belgian, who was trying his very best to stop him.
As the ball rippled the net, there came a groan of pleasurable surprise. Then there was a wow sound.
Finally, he was applauded by some who later wanted him to fail with the kind of fervour that makes you appreciate the level Salah has now reached.
The eyes of spectators, managers and opponents are on him: he is the player people relish watching, whether you want him to do well or not.
The focus on him invites criticism, much of it unfair. He was pulled and dragged by Sean Morrison in the lead up to Liverpool's penalty but he did not go down. It was only when he was heaved that he decided it was probably time to really highlight there had been an infringement. If he stays on his feet, does Martin Atkinson intervene?
English football culture frowns upon diving but it invites the phenomenon because it so often fails to recognise a foul unless the player falls. On the basis of that, brilliant footballers like Salah cannot really win.
Defenders are trying everything to stop him and in fairness to Morrison, he was reasonably clever in his attempts because of the way he slowed Salah down and positioned his own body.
If what happened next is not a foul, though, there are no fouls and no penalties.
Salah's form since his spring break last month has been fabulous.
A constant threat. A constant menace. He is working harder than he ever has. He is tracking back and helping out in defence. He seems fresher than he did at the start of the season.
As his goal at Southampton proved, he is capable of transforming pressure in defence to an outcome-defining attack in under eight seconds.
This could have been repeated on Sunday in the Welsh capital on two occasions in the first half and each time it took at least two Cardiff defenders to stop him.
There are other signs that Salah is growing more comfortable in his fame. He rarely gives interviews and since joining Liverpool he has stopped to talk to the media in the mixed zone of any stadium just once - a year ago when he reached goal number 40 for the season.
He was polite, engaging and humble but it was clear he'd rather someone else was talking on his behalf.
Being one of the world's iconic footballers is not an easy position to be in, especially if you are from Egypt where democracy has been replaced by totalitarianism. There might be things Salah wishes to say about this but he has not.
His interview with Time magazine, published last week, indicated he'd prefer to distance himself from politics and stand for something much bigger. It was incredibly brave of him to speak out about the treatment of women because it cuts through all societies and to a large extent, explains so much of the world's prejudice.
We see Salah as a wonderful footballer but maybe he will be remembered as much more than that.
The fact he is willing to openly discuss an issue that affects every religion - Muslim, Christian or otherwise - as well as every place, indicates he is growing more confident in himself and realises the difference he can make.