it’s part of the game in any offline environment. even on H2H cabs if you’re in a quiet environment you can hear the buttons on the other side.
you can map empty buttons and use them in situations where you suspect he’s listening
on arcade (usually no empty buttons) in a lot of games you can hit the start button (probably works better on H2H or games where the start button isn’t way off in the distance)
you can whiff jabs and shorts (standing and crouching) to bait out reaction normals and then punish those reactions
many arcade players actually struggle against empty buttons! I remember Korean KOF13 players complaining about Bala’s empty buttons a couple Evos ago, and a similar situation in 3s Deshiken vs Tokido at Shadowloo Showdown. even if you aren’t consciously listening and trying to gain an advantage by listening to buttons, someone hitting empty buttons in tense footsie situations or during hard confirms can screw you up.
it’s part of the game outside the game. there’s other elements as well, in addition to button listening - I’ve heard that Valle has shoulder fakes he’ll use to throw people off. body language, sounds, fake buttons, physically shaking the cabinet, all these are things you can either use yourself, or have to at least be conscious of in offline play.