@ Blondy - My voice changed during AC chemo almost overnight. I lost all my reflexes and coughing, sneezing and giggling were all quite difficult. I'm totally tone deaf so never try to sing but found that I could only talk at a whisper. Several people said I 'sounded' different. I finished chemo in November last year and my voice seems back to the 'new normal' that I'm becoming accustomed to for everything.
I was told that my throat would be damaged during radiation cause it was in the way but I feel no difference after the radiation which left me with 3rd degree burns but no throat damage.
I would blame the chemo for your voice.
Just another little side effect that oncologists are always surprised to hear of.