Uptalk had been spotted even earlier, in 1975 by linguist Robin Lakoff, who wrote that "there is a peculiar sentence pattern… which
has the form of a declarative answer to a question, and is used as such, but has the rising inflection typical of a yes-no question."
The potential spread of vocal fry could be an interesting case study. The phenomenon sees the speaker use their larynx in such
way that a lower creaking or rattling quality enters their voice.
We don't fully recognise it, but our manner of speech is constantly changing based on how those around us speak.