The ref didn't call it. Kallberg made a fuss about it and the ref just meekly went along with it. In such high pressure moments it's normal to make noises as a reflex. If you want to complain about noise making as a distraction there are far worse examples and I don't even have to list them here because they're just that common. If anything Sweden's third singles player should have been yellow-red carded for smashing the ball against the table and throwing it around.
So the ref took the input of the player that was distracted by the noise in making the decision, and you are faulting Kallberg for speaking up and the ref for listening? That's kind of a bizarre take, and only makes sense if you already 100% believe that the distraction is unintentional.
I have watched hundreds of hours of TT in the past couple of years and I've never even once seen a player shout out something while another player was trying to receive, much less during a match point like this. I've seen players cho early because they thought they won the point, or grunt when they hit the ball, but I've never ever seen the "my opponent is about to make contact with my critical serve" shouting reflex. What I have seen is people doing illegal things hoping they'll get away with it (illegal serves, stomping feet to distract a serving opponent, etc.). In my brain, there is no other explanation.
Of course, I know nothing about this Singaporean player. If this is common with her, then you can show us some other moments she's randomly making noises. Otherwise, I'd put money on it being intentional and, therefore, an attempt to cheat.
