By Reena Narayanan, Senior Audiologist at Mediclinic Al Madar and student of SAERA. Published on the Global Journal of Otolaryngology.
Acoustic Reflex Latency (ARL) is the time interval between onset of an intense auditory stimulus and onset of middle-ear muscle contraction. Unlike pure tone audiogram, the usual procedure to detect middle ear disorders and conductive hearing loss, ARL can differentiate between cochlear and retrocochlear pathologies, yields information about the nature of the conductive disorder, can detect mild conductive problems and is useful for patients that require cooperation.
The present study done on 30 normal-hearing female subjects between the age range of 20-30 years old shows no significant differences between the results in the left and right ears of the subjects using the Acoustic Reflex Threshold (ART) latency parameters tested from 500 Hz to 4,000 Hz and the Interaural Latency Difference (ILD) for initial latency of 500 Hz with ILD for initial latency of other frequencies. The present study might be used as normative data for future research on ARL in patients with various cochlear and retrocochlear lesions as part of a differential diagnosis.