Rollover
The paradoxical decline in word recognition score when presentation intensity is increased beyond the optimal level, considered a sign of retrocochlear pathology.
Full Definition
Rollover is a phenomenon observed in performance–intensity functions for speech, where a patient's word recognition score improves with increasing intensity up to a peak and then decreases as the level is raised further. A rollover index—calculated as (maximum WRS minus WRS at highest level) ÷ maximum WRS—of 0.45 or greater is often cited as indicative of retrocochlear dysfunction, such as that caused by a vestibular schwannoma or auditory neuropathy. The rollover effect is clinically important because it distinguishes retrocochlear from cochlear hearing loss patterns. Editors should note that 'rollover' is used as a single unhyphenated noun and adjective in audiology and should not be confused with the general computing or financial sense of the word.
Usage
Usage note: Always contextualise 'rollover' with a qualifying phrase (e.g., 'speech rollover,' 'PI-PB rollover') in documents that may be read outside audiology to avoid confusion with unrelated uses of the word.
In Context
- "A rollover index of 0.50 was calculated from the PI-PB function, prompting referral for retrocochlear assessment." — Diagnostic audiology report
- "The term 'rollover' in this context refers to speech score degradation at high intensities, not a carry-over of financial figures; ensure context is unambiguous." — Interdisciplinary editorial note