Recruitment measured by automatic audiometry.

Abstract

<h3>Introduction</h3> Because loudness recruitment has assumed significant clinical and diagnostic importance, many tests have been devised to demonstrate its presence. One such test involves automatic audiometry. In 1947, when Békésy¹first described his automatic audiometer, he also suggested that the amplitude of excursions of the audiometric tracing gives a measure of the difference limen (DL) for intensity. It was further reasoned that if recruitment were the result of an abnormally rapid growth of loudness, this rapid growth should be the result of diminished DL's. Therefore, diminished excursions in automatic audiometry have been taken as direct indications of the presence of recruitment. The identity of diminished excursions on the automatic audiogram with DL's and recruitment has been supported by such authors as Reger,⁹Lundborg,⁴and Meurman.⁵On the other hand, Palva,⁶one of the more prolific critics of the measurement of recruitment by automatic audiometry, has