Recruitment
An abnormal, rapid growth in perceived loudness once a sound exceeds the hearing threshold, typically associated with cochlear (outer hair cell) damage.
Full Definition
Recruitment is a phenomenon in which the subjective loudness of a stimulus increases disproportionately rapidly as the stimulus intensity is raised above threshold. It is a hallmark of cochlear pathology, particularly outer hair cell dysfunction, and is distinct from hyperacusis, which involves discomfort at normal loudness levels even in individuals with normal thresholds. Clinically, recruitment is assessed through loudness growth procedures, alternate binaural loudness balancing (ABLB), or the short increment sensitivity index (SISI). Editors must distinguish 'recruitment' from 'hyperacusis' carefully, as they are frequently conflated in lay and semi-technical writing. The term should not be used loosely to mean simple sensitivity to loud sounds.
Usage
Usage note: Distinguish clearly from hyperacusis in editorial copy; recruitment is a measurable audiometric phenomenon, whereas hyperacusis is a broader clinical condition.
In Context
- "Recruitment was confirmed via alternate binaural loudness balancing, consistent with a cochlear site of lesion." — Diagnostic audiology case report
- "The draft incorrectly used 'recruitment' to describe the patient's general sound sensitivity; the correct term in this context is hyperacusis." — Editor's annotation on a patient information leaflet