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

Abstract

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.