American researchers from Brown University have made an interesting discovery: whether people speak fast or slow, they generally convey information (meaning) at the same rate. It seems counterintuitive but if you pay close attention to conversations you might reach the same conclusion.
Fast or slow talker -- it's all the same
"It seems the constraints on how much information per second we should transmit are fairly strict, or stricter than we thought they were," said Uriel Cohen Priva, author of the study in the March issue of Cognition and assistant professor in the Department of Cognitive, Linguistic and Psychological Sciences at Brown University.
What Priva and colleagues suggest is that there's a narrow channel of communication data that we can tap into when we're trying to converse. This channel ensures that we do not provide too much or too little information at a given time. There's a pattern to how fast and slow talkers convey information. The fast talker tends to use common words and simple syntax while the slow speaker tends to use rarer words and more complicated wordings.
There's a pattern to how fast and slow talkers convey information. The fast talker tends to use common words and simple syntax while the slow speaker tends to use rarer words and more complicated wordings.
For instance, a speaker might use rarer or more complex words to hacksaw verbosity, which is the same as saying "remove very long and repetitive words". That's two words vs six which means you could say the same thing roughly three times faster or convey information at the same rate if you spoke three times slower. According to information theory, rarer words convey greater "lexical information" while complicated syntax, such as passive voice, conveys greater "structural information".
To investigate constrained information rate, the researchers analyzed word-for-word 2,4000 annotated telephone conversations and 40 lengthy interviews. In total, 398 people were involved in the study.
For each speaker, the team measured things like how much lexical and structural information they conveyed, as well as the speech rate. The researchers also measured how often a speaker used the passive voice compared to the active voice. A complex statistical framework was then applied to determine the relative frequency of words which took into account the age, gender and the speech rate of the other person involved in the conversation.
Ultimately, the researchers spot a pattern: as speech sped up, the information rate declined.
"We could assume that there are widely different capacities of information per second that people use in speech and that each of them is possible and you can observe each and every one," Cohen Priva said. "But had that been the case, then finding these effects would have been very difficult to do. Instead, it's reliably found in two corpora in two different domains."
Priva thinks that the constrained channel may have been socially imposed to the benefit of the listener. To back his hypothesis, Priva mentions one of the study's findings which suggests men conveyed more information than women at the same speech rate. Priva says that there's no reason why the information conveyed at a given rate differs by gender. Instead, it may be that women are more concerned with making sure listeners understand what they're saying.