Subvocalization, or silent speech, is defined as the internal speech made when reading a
word, thus allowing the reader to imagine the soundof the word as it is read. This is a natural process when reading and helps to reduce cognitiveload, and it helps the mindto access meanings to enable it to comprehend and remember what is read. Although some people associate subvocalization with moving one's lips, the actual term refers primarily to the movement of muscles associated with speaking, not the literal moving of lips. Most subvocalization is undetectable (without the aid of machines) even by the person doing the subvocalizing.
Subvocalization involves actual movements of the
tongueand vocal cordsthat can be interpreted by electromagneticsensors. Since 1999 NASA, as part of its Extension of the Human Senses program, has been working on a system that can interpret a limited number of English words using nervous signals gathered from sensors placed on the throat's exterior. Chief Scientist for Neuroengineering at NASA Ames Research Center, Dr. Chuck Jorgensen, has suggested that it could have potential applications for rescue operations people, security and special operations forces, people with vocal cord problems, and might even find a place in gaming.
speed readinggenerally claim that subvocalization "places extra burden on the cognitive resources, thus, slowing the reading down." These claims are currently backed only by controversial, sometimes non-existent scientific research; in some cases, concepts are drawn from pseudoscienceand urban myths about the brain. Speedreading courses often prescribe lengthy practices to eliminate subvocalizing when reading. Normal reading instructors often simply apply remedial teaching to a reader who subvocalizes to the degree that they make visible movements on the lips, jaw, or throat.
There is no evidence that normal non-observable subvocalizing will negatively affect any reading process Carver, R.P-Prof (1990) Reading Rate: A Comprehensive Review of Research and Theory (1990)] At the more powerful rates (memorizing,
learning, and reading for comprehension), subvocalizing is very detectable by the reader. At the less powerful, faster rates of reading, (skimming, and scanning) subvocalization is less detectable. For competent readers, subvocalizing to some extent even at scanning rates is normal.McWhorter, K. (2002) Efficient and Flexible Reading. Longman]
It may be impossible to totally eliminate subvocalization because people learn to read by associating the sight of words with their spoken sounds. Sound associations for words are indelibly imprinted on the
nervous system—even of deafpeople, since they will have associated the word with the mechanism for causing the sound or a sign in a particular sign language. Subvocalizing is an inherent part of reading and understanding a word, and micro-muscle tests suggest that subvocalizing is impossible to eliminate. Attempting to stop subvocalizing is potentially harmful to comprehension, learning, and memory. At the more powerful reading rates (100-300 words per minute), subvocalizing can be used to improve comprehension.
* [http://www.nasa.gov/home/hqnews/2004/mar/HQ_04093_subvocal_speech.html NASA Develops System to Computerize Silent, 'Subvocal Speech' ]
* [http://www.forbes.com/free_forbes/2006/0410/084.html?partner=yahoomag NASA researchers can hear what you're saying, even when you don't make a sound ]
* [http://www.tfot.info/content/view/80/58/ An interview with NASA's Chuck Jorgensen on the Subvocal Speech] - including pictures and video of the technology.
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