>Barb Mallut Thanks, I am collating all this info on collagen. My husband has also been told that he has unequal tone... strength in his vocal chords. His voice sorta cracks up and goes into two tones when he forces it for the low "shouts" needed for the LSVT. Makes some interesting sounds though, and he tells the instructors that the Tibetan monks spend years practising the technique! So why worry. But they do, and make him stop when it happens. He also reckons he once or twice got a high sort of sound overlaying it (like ethereal flute music). Like the Harmonic Choir. Have you heard them? Cheers Joy Graham