Sukuna's voice has often echoed in his head since Yuuji consumed the curse. Annoying. Distracting. But as time goes on, Yuuji has learned how to tune it out pretty effectively, and the curse gets quieter and quieter. It's a small, peaceful relief.
That is, until Yuuji goes to sleep one night, exhausted from training, and finds himself in the cursed domain, looking up at Sukuna who sits cross-legged, relaxed, surveying him with disdain.