Speech shadowing

Speech shadowing is an experimental technique in which subjects repeat speech immediately after hearing it (usually through earphones). The reaction time between hearing a word and pronouncing it can be as short as 254 ms or even 150 ms. This is only the delay duration of a speech syllable. While a person is only asked to repeat words, they also automatically process their syntax and semantics. Words repeated during shadowing imitate the parlance of the words overheard more than the same words when read aloud by the subject.

Functional imaging finds that the shadowing of nonwords occurs through the dorsal stream that links auditory and motor representations of speech through a pathway that starts in the superior temporal cortex, goes to the inferior parietal cortex and then the posterior inferior frontal cortex (Broca's area).

Speech shadowing was first used as a research technique by the Leningrad Group led by Ludmilla Andreevna Chistovich in the late '50s. It has been used in research upon speech perception and stuttering.