One of us has hypothesised that the 'voices' of schizophrenic patients
reflect altered preconscious planning of discourse that can produce i
nvoluntary 'inner speech' as well as incoherent overt speech. Some sch
izophrenic patients reporting voices do not, however, have disorganise
d speech. We hypothesise that these 'counterexample' patients compensa
te for impairments of discourse planning by reducing language complexi
ty and relying on highly rehearsed topics. A 'language therapy' design
ed to challenge and enhance novel discourse planning was administered
to four such patients; three had significant albeit temporary reductio
ns in the severity of their voices. These clinical findings provide fu
rther evidence that alterations of discourse planning may underlie hal
lucinated voices.