Is the husband's prayer considered valid if he cannot hear or speak and performs the prayer solely by intention without reciting the Quran? What is the correct way for him to pray if his prayer is not valid? And will the wife be rewarded for marrying a person with a disability?

This person must learn what Allah has made obligatory upon him. His relatives and wife must teach him the rulings of purity and prayer practically, and help him memorize Al-Fatihah, Al-Tashahhud (definition), and what is necessary for prayer and other obligatory acts of worship. He should also be taken to the mosque because prayer does not cease to be obligatory for him as long as he is sane and capable of learning and performing it. What he is unable to do, he is not obligated to perform. The wife's patience with a disabled husband and fulfilling his rights, seeking Allah's pleasure thereby, holds a great reward, and the reward is commensurate with the hardship.