The significance of auditory recruitment within the framework of auditory theory today is claiming the attention of a large number of laboratories and clinics. Data relating to the manifestations of the recruiting person are being analyzed. Tests are being devised to indicate the presence or absence of recruitment in the person with impaired hearing. A survey of the literature indicates that recruitment tests can be subdivided into tests of loudness balance, difference limen, and speech sound discrimination.
The purpose of the present investigation was to establish, by means of more rigorous statistical analyses than have hitherto been reported, the capability of a series of tests to distinguish between normal hearing persons and those whose auditory perception is characterized by recruitment in the loudness function. The following tests were subjected to such statistical analyses: (1) range of comfortable loudness (RCL) test, (2) difference limen (DL) test, and (3) speech sound discrimination
SPUEHLER HE, HANLEY TD. An Auditory Loudness Recruitment Test BatteryAnalysis and Comparison of Subtests. AMA Arch Otolaryngol. 1957;65(2):183–190. doi:10.1001/archotol.1957.03830200079010