Sampha's debut album Process received glowing reviews upon its February release, with the NZ Herald giving it five stars and declaring it "a debut album of breath-taking poise".
Speaking to the nzherald ahead of his May performance at the Powerstation this year, Sisay said the high emotions that run through Process were mined from personal experience.
"They're definitely over-magnified versions of particular emotions. It's like someone who paints a picture or writes a film, some of those feelings are definitely things I've gone through personally."
Sampha's debut came after years of background work with big name acts like Beyonce, Frank Ocean, Drake and Solange.
The Mercury Prize is an annual award honouring the best album from the UK and Ireland.
Winners receive a trophy and £25,000 (NZ$46,000).