The scariest thing about this clip, besides the sound, is it doesn't look like he's putting much power behind the punch.
Maybe a 7 on a scale of 10.
His reaction to the 999 score is 'Is Normal.'
And yes, I get those punching machines aren't officially regulated & measured. Still impressive nonetheless.
It's a gymshark promo video for an event, and there is some subtle added visual effects, maybe sounds effect too. Since apparently, gymshark gives 10 000$ to anyone who can match it, I suspect the score is not real either.