Is it forbidden to speak while someone is praying or reciting the Qur’an, and how accurate is the saying, “Whoever makes a worshiper laugh has made seventy angels cry”?

The prohibition of sound during prayer is restricted to sound that causes disturbance to the worshippers. The one who prays is intimately conversing with his Lord, and it is not appropriate for some of them to raise their voices over others with the Qur'an. As for the saying, "Whoever makes a praying person laugh has made seventy angels weep," it is not authentic and has no basis.