A western civ prof in college, simply read the book for 50min at the podium. And he used to clear his throat about every other second.
One time I couldn’t take it, so I counted. 442 times in 50 minutes he went HUH-HUH. God that was so annoying.
I had a professor Freshman year in college who constantly said ‘um’. In one class I started tally marking each ‘um’, at 300 I couldn’t take it anymore and left - bought class notes and showed up for the tests.