Beethoven was deaf. Everyone knows that. But he wasn't the only one. The most famous other composer was probably Bedrich Smetana, a Czech composer who is most famous for his work Ma Vlast (My Country). 
Smetana went deaf and because of that also went insane in his later years. Ma vlast is one of the most popular classical works that exist today.
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Bedrich Smetana: deaf and later, insane