I am a writer based in Austin, Texas, who is working on a book about verbal blundering, including speech slips and speech disfluencies. I wonder if you can help me find early recorded examples of these features of spoken language, including:

uh, um, and other filled pauses
repeated words ("I went went to the store")
restarted sentences ("The main thing is -- Look at it this way...")
stuttering (both by "normal" speakers and by people who stutter)
silent pauses (not for effect, but because the speaker is looking for a word)


"Freudian slips"
garden variety anticipations, perseverations, omissions & blends of sounds

grammatical errors
other phonological, syntactic or semantic gaffes

I would very much appreciate being in touch with people who can speak about these features of spoken language in their collections, not only in detailed terms (as in being able to identify specific recordings that contain them) but also the socio-technological issues involved in recording them (e.g., when cheaper recording techniques allowed people to record spontaneous speech, not only formal, pre-prepared speech).

Below I am appending a piece I wrote for the New York Times about the scientific study of "uh" and "um." My work about language has appeared in the New York Times, the Atlantic Monthly, Legal Affairs, Lingua Franca, Brill's Content, and Technology Review, and my reporting on culture & politics has appeared in Rolling Stone, Wired, the Texas Observer, and a number of other publications.

Thank you very much in advance.

Michael Erard

Think Tank: Just Like, Er, Words, Not, Um, Throwaways

January 3, 2004


If you were hearing this instead of reading it, you might
notice a pause here and there tucked between the phrases,
filled with a familiar, soft hum or rumble - an um or uh.

Though a bane to teachers of public speaking, people around
the world fill pauses in their own languages as naturally
as watermelons have seeds. In Britain they say uh but spell
it er, just as they pronounce er in butter.

The French say something that sounds like euh, and Hebrew
speakers say ehhh. Serbs and Croats say ovay, and the Turks
say mmmmm. The Japanese say eto (eh-to) and ano (ah-no),
the Spanish este, and Mandarin speakers neige (NEH-guh) and
jiege (JEH-guh). In Dutch and German you can say uh, um,
mmm. In Swedish it's eh, ah, aah, m, mm, hmm, ooh, a and
oh; in Norwegian, e, eh, m and hm.

These interruptions, it turns out, plague machines more
than people - speech-recognition systems in particular - so
researchers have increasingly been turning their attention
to uh and um (among other so-called disfluencies).

"If someday you want machines to be as smart as people,
then you have to have machines that understand speech
that's natural, and natural speech has lots of disfluencies
in it," said Liz Shriberg, a research psychologist at
S.R.I. International, a research company based in Menlo
Park, Calif. Uh and um might tell a computer about a
speaker's alertness or emotional state so the system can
adjust itself and let people speak naturally to
speech-to-text programs.

Well before the invention of speech recognition, Frieda
Goldman-Eisler, a psychologist in London in the 1950's,
inaugurated the modern study of disfluencies by developing
instruments that counted pauses in speech and measured
their duration. Ms. Goldman-Eisler, who was looking for a
way to make psychiatric interviews more efficient, found
that 50 percent of a person's speaking time is made up of
silence. She also hypothesized that a speaker planned his
next words for the length of the uh or um.

Around the same time a psychiatrist at Yale, George Mahl,
counted uhs and nine other speech disfluencies in order to
measure a person's anxiety level, calculating that during
every 4.4 seconds of spontaneous speech, on average, one
disfluency occurs. Eighty-five percent were uh and um,
restarted sentences and repeated words. A slip of the
tongue - upon which Sigmund Freud practically built an
intellectual career - occurred less than 1 percent of the

Ms. Goldman-Eisler and Mr. Mahl treated uh and um as
symptoms of nervousness and verbal struggle. But once
cheap, fast computers made digitized speech easy to study
in the 1990's, the approach changed. Researchers began to
study verbal pauses for meaning; they focused on the words
as information.

By far the newest - and most controversial - idea comes
from Herbert Clark, a psychologist at Stanford, and Jean
Fox Tree, a psychologist at the University of California,
Santa Cruz, who determined that speakers use (and listeners
understand) uh and um in distinct ways. Uh signals a
forthcoming pause that will be short, while um signals a
longer pause, she said. Uh and um are not acoustic
accidents, but full-fledged words that signal a delay yet
to come. Of course that is not necessarily a good thing in
public speaking. "It makes you look weak when people have
come to hear you prepared, and you're not prepared," Mr.
Clark said.

Ms. Fox Tree, who is a former student of Mr. Clark's,
became interested in uhs and ums as an undergraduate
majoring in linguistics at Harvard. There she realized that
theories of language could not account for the fragmented
nature of ordinary conversation.

"I thought, here's something you hear in every single
conversation during the day, some kind of disfluency, and
yet people treat them as if they're garbage," she said.
"Why are they there? Why do we use them?"

Ms. Fox Tree studies other discourse markers like you know,
I mean and oh, and is working on so and and. Her dream
topic is like.

"I waited before I got tenure to study like," she
confessed, "because I thought it was going to be messy and
hard to get a hold of, and I would spend all this time
studying it."

Ms. Shriberg agrees that these disruptions are more than
white noise. "When you realize these things are distributed
in very clean ways and have a very elegant structure," she
said, "then you can see they're not garbage at all."

Heather Bortfeld, a psychologist who studies infant
language development at Texas A&M University, discovered
this through personal experience. While living in Madrid
during her junior year in college, she noticed the distinct
sounds the Spanish used to fill their pauses.

"These were often conveying important information that I
had to learn about," Ms. Bortfeld said. "And then I had to
learn how to make them myself in order to sound more native
and to really be speaking Spanish correctly."

In 2001 Ms. Bortfeld and others reported in the journal
Language and Speech that speakers taking a more active role
in tasks said uh and um, repeated words and restarted
sentences more frequently than those in a passive role. Men
say uh and um more than women, though their overall
disfluency rate was the same. One piece of conventional
wisdom fell by the wayside: whether or not the speaker and
listener knew each other had no effect on uh or um rates.

But it may be Nicholas Christenfeld, a psychologist at the
University of California, San Diego, and other researchers
who have come up with the most appealing findings. He
counted uhs among professors giving lectures and found that
the humanities professors say you know and uh 4.85 times
per minute, social scientists 3.84 and natural science
professors 1.39 times, which, he said, suggests that
humanists have more expressive options from which to

And for those trying to minimize their verbal tics, Mr.
Christenfeld also found that drinking alcohol reduces ums.