Football without Fans

Crowd noise is added by the broadcast producer. Sky for example worked with EA Sports to leverage the engine they have for their FIFA game that is tailored to each team, they also allow you turn it off so you can hear the shouts from players and managers. Producers with lower budgets use lesser systems.

Yeah, a guy I worked with used to work for Sky. They’ve special buttons for special events and crowd reactions.
Like a “ooooohhhhhhaaaawwwww” when the ball goes over the bar by a fraction.