Deficits in recognition and processing of rapidly successive phonetic elements of speech in language-learning impaired (LLI) children, aged 5 to 10 years, treated at Rutgers University, Newark, NJ, and University of California, San Francisco, were improved by listening to acoustically modified synthetic speech and by daily training with computer “games” designed to modify temporal processing and phoneme perception. A two-stage acoustic speech processing algorithm was developed: 1) prolonging the duration of the speech signal by 50%, and 2) enhancing by 20dB the fast (3-30 Hz) consonant speech elements relative to the slowly modulated vowels. After 1 month of daily training with this acoustically modified speech presented as listening exercises on audiotapes, test scores significantly improved by approximately 2 years, with each of seven LLI children achieving normal levels of speech discrimination and language comprehension. In a second study involving 22 LLI children divided into two matched groups, both groups received the same training exercises used in the initial study but only one group was presented with temporally adaptive computer games and acoustically modified speech exercises. Significantly larger improvements in speech discrimination and language comprehension were achieved by the LLI children receiving the acoustically modified speech training as compared with improvements recorded for subjects receiving natural speech training. 
COMMENT. Remarkable and significant improvements in receptive speech and language comprehension were demonstrated in language-learning impaired children who received training with acoustically modified speech stimuli. Brief, rapidly changing components of speech were temporally prolonged and emphasized, and coupled with adaptive training exercises.
LLI children have been found to have a temporal processing deficit, expressed by limited identification of brief phonetic elements of speech and impaired sequencing of short-duration acoustic stimuli presented in rapid succession. When presented in slower forms and rates, the stimuli are correctly perceived and receptive language is improved. Temporal processing deficits of 11 LLI children studied at the Center for Integrative Neurosciences and Coleman Laboratory, University of California, San Francisco, were corrected by adaptive training exercises and computer games designed to modify temporal processing skills.