Er

As the years go by, speech reverts to childhood levels of disfluency, with more pauses, more errors, more repeated words, but even the peak years are not great: up to 8 percent of the average person’s word output consists of meaningless fillers and placeholders like um, uh and er.

um and er

Although Shakespeare refers to “hums and ha’s,” sifting through etiquette manuals and public-speaking guides turns up scant evidence of a prohibition against ums, ers and uhs, which are profuse in the first recording of Thomas Edison’s voice, in 1888. Mr. Erard, rather ingeniously, traces the prohibition on um and other speech flaws to the advent of radio in the early 1920s.