A spectator walks on or shouts during a point
Anything that is not part of the game coming onto the court, a person included, means the point is replayed. A noise from the crowd is not covered by name in the rules, so it is the umpire's call, or yours together in a social game.
Someone on the court
If a spectator, a child or a dog wanders onto the court during a rally, stop and call it straight away. The point is replayed, because something that is not part of the game has come onto the court.
Noise and distractions
The interference rule covers players putting off an opponent. A shout or a phone from outside the court is not mentioned by name. The rules do allow a replay for an unexpected interruption that has nothing to do with the players, and the umpire decides whether a noise was one. In practice, ordinary crowd noise is not treated as an interruption.
Players and spectators
Players must be polite to everyone at a competition, playing or not, and aggressive behaviour towards spectators is treated especially seriously.
Perguntas
What if someone walks onto the padel court during a point?
Call it at once and replay the point.
Is crowd noise a let in padel?
Normally not. A sudden, unexpected disturbance may be, and the umpire decides.