“Over time the speaking voice may become noticeably hoarse and breathy. It may also start to ‘cut out’, around certain notes, giving characteristic ‘voice breaks’. These are most obvious when the voice is used quietly.”
In the past, surgery to remove vocal nodules was the preferred treatment, but this was often unsuccessful and came with a chance of being a “career killer”.
Although it is unknown when Plant underwent surgery on his vocals. The Grunge, a popular music site, explains that in the years of 1972 to 73 Plant’s vocals changed, hinting that he had undergone the potentially dangerous surgery, but was lucky not to have lost his singing ability.
Nowadays, surgical techniques try, whenever possible, to ensure that the gelatinous layer of the Lamina Propria – a thin layer of connective tissue that forms part of the respiratory tract – is preserved.