Simplify the following text for a Grade 9 native English-speaking person.
Original: In late 1994 , after touring in support of Superunknown , doctors discovered that Cornell had severely strained his vocal cords , and Soundgarden canceled several shows to avoid causing any permanent damage .
Simplified: In late 1994 , after touring in support of Superunknown , doctors discovered that Cornell had severely strained his vocal cords . Soundgarden canceled several shows to avoid causing any permanent damage .