Why did you use parentheses when Kyle spoke?

I had a choice there. I could have written Kyle's dialogue straight, as if he enunciated words in the same way that other characters did; I also could have written it in a form of dialect. Neither option seemed satisfactory, because Kyle's problem wasn't only that he had trouble speaking, but the words he did speak were spoken poorly. Straight writing wouldn't have captured that. Had I written in dialect, more than likely it would have added unnecessary confusion to the novel. My own feeling is that dialect should be used sparingly in literature. Instead, I opted to write it straight, with how it sounded put in parentheses.