Scientific Correspondence

Nature 398, 760 (29 April 1999) | doi:10.1038/19652

Cognitive restoration of reversed speech

Kourosh Saberi1 & David R. Perrott2

Speech is the most complex auditory signal and requires the most processing1. The human brain devotes large cortical areas2,3 to deciphering the information it contains, as well as parsing speech sounds produced simultaneously by several speakers4. The brain can also invoke corrective measures to restore distortions in speech5; for example, if a brief speech sound is replaced by an interfering sound that masks it, such as a cough, the listener perceives the missing speech as if the brain interpolates through the absent segment. We have studied the intelligibility of speech, and find it is resistant to time reversal of local segments of a spoken sentence, which has been described as "the most drastic form of time scale distortion"6.

  1. Division of Biology 216-76, Caltech, Pasadena, California 91125, USA
    e-mail: Email:
  2. Departmentof Psychology, California State University, Los Angeles, California 90032, USA