why is ohello very admant and does not here the plea of his wife?

Othello sees things in extremes. Either Desdemona is pure and chaste or she is "loose" and disloyal: there is no in-between. This "Madonna- whore complex" was frequently seen in Shakespearean male characters. Once evil Iago planted the seed of discontent in Othello's head, the paranoia came easily. Othello refused to listen to reason rather he succumbs to his rash nature. Othello feels he was made a dreaded "cuckold" and nothing else, not even Desdemona's desperate pleas, will change his mind.