Do thoughts have sound? Differences between thoughts and auditory hallucinations in schizophrenia

Cognitive theories about auditory hallucinations maintain that inner speech is erroneously interpreted as coming from an external source. Few first-hand accounts of patients' experiences have been made, so there is limited knowledge of the process through which patients distinguish their auditory verbal hallucinations (AVHs) from ordinary thoughts. 89 individuals diagnosed with schizophrenia, some experiencing acute hallucinatory symptomatology (Sz-AVHs) and some who were not (Sz-noAVHs), were assessed along with 48 individuals from the general population using the Auditory Hallucinations Assessment Questionnaire (AHAQ; Cuevas-Yust, Rodríguez Martín, Ductor Recuerda, Salas Azcona, & León Gómez, 2006). The Schz-AVHs group reported hearing ordinary thoughts at the same volume as their auditory hallucinations (p = .53) and spoken words (p = .89). In contrast, the Sz-noAVHs and general population samples reported hearing spoken words louder than their own thoughts (p = .002; p = .04). In comparison to these last two groups, the Sz-AVHs group described the sound of their thoughts as louder. These findings are consistent with the cognitive hypothesis of auditory verbal hallucinations. Confusion identifying the source of auditory hallucinations could be due, in part, to "hearing" one's thoughts at the same volume as auditory hallucinations and spoken words.