Although "kar" means "deaf", it is not certain this man was actually deaf. "Kar" may just have been a surname, or he may just have been hard of hearing. He led a revolt against a sultan in what is now part of India, took possession of the city of Badrakut, and made it capital of his kingdom. The sultan's military commander counterattacked and captured Kar. The sultan pardoned Kar and exiled him to the city of Ghazna. Later, Kar broke his promise to stay away and returned home, whereupon the sultan had him arrested and executed.
The Travels of Ibn Battuta, vol.3, p.727-728.