The prevalence and phenomenology of auditory hallucinations among elderly subjects attending an audiology clinic

Background Studies of auditory hallucinations are scant. Method To determine the prevalence and phenomenology of auditory hallucinations among elderly subjects with hearing impairment. Objective We surveyed 125 men and women aged 65 years and over referred to the Audiology department of a university-affiliated primary acute-care hospital. Results The prevalence of auditory hallucinations was 32.8% (95% confidence interval (CI) 24.7-41.8). These hallucinations represented a spectrum of phenomenology from elementary personal impressions to complex percepts. The types of auditory hallucinations included humming or buzzing (35.9%), shushing (12.8%), beating or tapping (10.6%), ringing (7.7%), other individual sounds (15.4%), multiple sounds (12.6%), voices (2.5%) or music (2.5%). Subjects with any type of hallucination were younger and had poorer discrimination scores in the left ear and impaired binaural discrimination with lip-reading. Subjects with hallucinations that had more qualities of a true percept heard different types of sounds and had lower reflex thresholds and better air conduction in the right ear. Conclusion Auditory hallucinations are frequent in elderly subjects with hearing impairment and seem to be associated with younger age and asymmetrical hearing impairment. Copyright (C) 2002 John Wiley Sons, Ltd.