"I had cancelled shoots 4-5 times to give rest to vocal chords which are just like muscles. And if you can control muscles, you can make anyone sounding similar to your voice," Hrithik said at a promotional press meet here.
"So I rested my vocal chords and kept rehearsing. In "Kaabil" 90 per cent of my character's voice is my voice," he added.
"I plan to do as much I can to campaign for the blind, who are the strongest-willed people. Playing blind makes you aware about the potential of human spirit."
Hrithik said he feels attached to Kolkata as it was the first place he made a public appearance in.
"My first public appearance was in Kolkata in 2000. My dida's (maternal grandmother) wish was that my first stage performance be here. There is Bengali blood in me.