In the beginning of Tokyo Ghoul, Tsukiyama appeared to be a confident, friendly, and intelligent ghoul. However, these were merely acts to lure his "prey" into the Ghoul Restaurant and to conceal his eccentric, cruel, and selfish personality. He considered himself a strong predator who would seek to devour the finest meals he made of his "prey" and would not hesitate to resort to any merciless tactics in order to achieve his goals. As a result, he was disliked by most ghouls in the 20th ward. His interest in European literature and language was shown in his gestures and mannerisms, his dialogue often peppered with random phrases of English, French, and Italian. Family associates have likened his intellectual gestures to those of his young father.

Here's a video to clip to get an idea of what his voice sounds like (you don't have to sound the same) https://www.youtube.com/watch?v=naVF-bs46BI