Professor Stephen Hawking speech on the NHS

In 1998, the narrator shares a personal story involving a flight to a conference, interactions with a fellow passenger, and subsequent health challenges. Upon returning to Cambridge, they reflect on personal experiences and invite David Harbour to discuss a surgery. The narrative concludes with an explanation of the larynx's primary function, emphasizing its role in protecting the lungs rather than producing voice.

What health issues did the narrator experience after the flight?

What misconception about the larynx does the text address?