Who is the first speaker in the book?

Life of Pi opens with a fictional author’s note, explaining the origins of the book. The author explains that while in India and floundering on the book he is trying to write, he travels to Pondicherry, where an elderly man, Mr. Adirubasamy, tells him he has a story for him that will make him believe in God. Adirubasamy tells the author about Pi, who the author manages to find in Canada, where Pi relates his story.