Answer:
The sentence type is compound-complex.
Explanation:
A simple sentence has only one independent clause. For example, "He never smiled."
A compound sentence has more than one independent clause; "He never smiled, he never frowned."
A complex sentence and compound-complex sentence are similar, but the first has only one independent clause with one or more dependent clauses, while the compund-complex sentence has more than one 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.
