Prevalence of acoustic reflexes in the United States

The acoustic reflex is a contraction of the middle ear muscles in response to high-level sounds. Acoustic reflexes are invoked as a protective mechanism in some damage-risk criteria (DRC). However, acoustic reflexes are not always observed among people without auditory dysfunction, and should not be included in DRC unless there is 95% certainty that 95% of the population have acoustic reflexes. In the current study, we present the prevalence of acoustic reflexes among people 12 years and older (N > 11,400), using data from the National Health and Nutrition Examination Survey (NHANES). The NHANES can be used to produce prevalence estimates generalizable to the non-institutionalized U.S. population. Ipsilateral reflexes were screened at two elicitor frequencies and detected using Frequentist methods and via Kalman filtering of the reflex trace. Reflexes are pervasive only among those with hearing thresholds better than 15 dB HL at all frequencies, and fall below the criterion certainty with poorer sensitivity even at lower frequencies. Age and tympanometric variables are also related to reflex detection. Reflex prevalence is generally high among young people with adequate hearing sensitivity for unrestricted military duty, but the prevalence is not uniform among audiometric configurations within this hearing profile.