But, I mean, let's be honest: Caroll's voice was incredibly weak during his final years, and even so, his Big Bird and Oscar voices were sounding exactly alike in the end. Even when I met him at the Knoxville Fanboy Expo back in 2017, speaking with him at his table was not unlike on SEINFELD when Kramer was dating that low-talker, it was rather difficult to hear him speak, and more often than not, he wouldn't be able to finish answering a question, so Debbie would have to speak for him.
You can get an idea of that from this Q&A panel and sing-along I filmed: