@Malavika Yes, I remember that (unlike Harimuraleeravam), this is a case where the audio was edited to make it look like it was done at a stretch. As I recall, Yesudas, in an interview or something, was appealing to contestants in music competitions not to attempt that, or maybe not to feel disappointed at not being able to do that, because it was actually achieved by manipulating the audio recording, and he did not sing it like that in real life
Whereas in Harimuraleeravam, the extended singing and the three-octave sangati immediately after that were done naturally, and, as is probably well-known, deliberately designed by Raveendran to show that Yesudas could still sing like that (because he'd been annoyed by some people's disparaging remarks about Yesudas' voice at the time)