One week after receiving new in-the-ear hearing aids, a 66-year-old man reports that his own voice sounds hollow and boomy, as if speaking inside a barrel, though others' voices sound clear. What is the mechanism of this complaint and its standard remedy?
- A Acoustic feedback caused by a loose fit, corrected by tightening the shell
- B Recruitment causing intolerance of his own voice, corrected by reducing maximum power output
- C Occlusion effect from bone conducted self-voice energy trapped in the closed canal, relieved by venting or an open dome ✓
- D Dead ear region in the low frequencies, corrected by switching to a power BTE instrument
Correct answer: C. Occlusion effect from bone conducted self-voice energy trapped in the closed canal, relieved by venting or an open dome
Explanation
A tightly sealed ear canal blocks the normal escape of bone-conducted low-frequency energy produced by the wearer's own voice, producing the hollow, barrel-like quality known as the occlusion effect. It is relieved by adding a vent to the mould or using an open or large-vented dome. Feedback produces whistling audible to others rather than altered self-perception, and recruitment relates to loudness discomfort for external sounds, not the wearer's own voice.
Reference: Cummings Otolaryngology Head and Neck Surgery, 7th ed.
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Written and medically reviewed by the StethoPrep medical team.