Answer:
The sentence type is compound-complex.
Explanation:
A <em>simple sentence</em> has only one independent clause. For example, "He never smiled."
A <em>compound sentence</em> has more than one independent clause; "He never smiled, he never frowned."
A <em>complex sentence</em> and <em>compound-complex</em> sentence are similar, but the first has only one independent clause with one or more dependent clauses, while the compund-complex sentence has <u>more than one</u> independent clause and at least one dependent clause.
In this sentence, there are 3 independent clauses (He never smiled, he never frowned, he never changed his voice) and at least one dependent clause. So this makes it a complex-compound sentence.