The only voice in the first book that I can see she has an interesting reaction to is, of all people, Theo's. He has "a deep voice that made Agatha's ears tingle." which is totally not what I heard him as in my head. Oh well. Gil is all touch and scent and facial expressions. They don't seem to have made much of voices in the first novelization, not even mentioning anything odd when Gill chews the scenery at the university.