 The guitar's output, through the VG-8, was transposed to any of her tunings in real-time.It was around this time that critics also began to notice a real change in Mitchell's voice, particularly on her older songs; the singer later admitted to feeling the same way, explaining that "I'd go to hit a note and there was nothing there".While her more limited range and huskier vocals have sometimes been attributed to her smoking (she was described by journalist Robin Eggar as "one of the world's last great smokers"), Mitchell believes that the changes in her voice that became noticeable in the 1990s were due to other problems, including vocal nodules, a compressed larynx, and the lingering effects of having had polio.