The purpose of this article is to give the practicing otolaryngologist an understanding of recruitment and a rapid screening test to determine the presence or absence of recruitment.
First let me say that recruitment is that characteristic of the nerve deafness in Ménière's disease which makes these ears sensitive to loud sounds. These ears are so sensitive that the patient cannot understand loud voices. Furthermore, these ears are sensitive to minute changes in intensity of sound, and the pitch becomes distorted.
Recruitment may be better understood if one visualizes the endolymphatic hydrops of Ménière's disease, producing dilatation of the aqueduct of the cochlea. This dilatation stretches the fibers of the basilar membrane. In the piano theory of hearing, these fibers of the basilar membrane have been compared to the strings of a piano. Continuing the comparison, when the fibers are stretched in Ménière's disease, the nerves are "on edge"; the