While wandering Youtube I managed to unearth a set of audio ASMR stories that fit this REALLY well and are exceedingly well acted, and best of all, free.
https://www.youtube.com/watch?v=v2s1...zvGWdZ&index=2
These might be some of the best transformation acting I have ever heard, you can really tell the difference between when Angela Jekyll and Lola Hyde are talking, but it also has a good transition between the two voices so you can hear them fighting for control.