occlusion effect
The hollow, booming quality of one's own voice perceived when the ear canal is occluded, caused by bone-conducted sound becoming trapped in the sealed canal.
Full Definition
The occlusion effect occurs when a hearing aid earmould or earplug seals the ear canal, causing bone-conducted sound energy from the wearer's own voice, chewing, or footsteps to be reflected back and amplified within the occluded canal space. This produces a subjective sensation of one's voice sounding hollow or as if speaking inside a barrel. Clinically, the effect is measured by comparing the level of sound in the canal with and without occlusion during phonation of a sustained low-frequency vowel. Venting the earmould or using open-fit devices is the standard remediation. Editors should note this term is sometimes misspelled 'occlusion affect'; the correct noun is 'effect.'
Usage
Usage note: Note the correct spelling: 'occlusion effect' (noun), not 'occlusion affect.' Distinguish from acoustic feedback, which involves signal leakage rather than bone-conducted trapping.
In Context
- "The patient complained of an occlusion effect; the audiologist responded by increasing the vent diameter of the earmould." — Hearing aid fitting report
- "Open-fit hearing aids were developed in part to minimise the occlusion effect in individuals with high-frequency hearing loss." — Clinical review article