What is the difference between become and be become?
"I become deaf" is the present tense.
"I am become deaf" is an archaic form of the present perfect tense. Today, we would say, "I have become deaf." This phrasing is only familiar in J. Robert Oppenheimer's quoting of the Bhagavad-Gita in reference to the creation of the atomic bomb: "I am become death, the destroyer of worlds".