प्रभु चरित्र सुनिबे को रसिया। राम लखन सीता मन बसिया॥ It is up to you; there isn't any certain rule to reciting Hanuman Chalisa. The greater you repeat, the more you grow to be near to Lord Hanuman. Your intellect must generally be 100% focused on the Chalisa although https://www.youtube.com/watch?v=ufkmD95y7fE