A lack of clinically demonstrable evidence causes many professionals to be reticent about recommending a CROS (contralateral routing of signal) hearing aid for unilaterally deafened individuals. This is a case report demonstrating, objectively, the benefit of a CROS hearing aid. Evidence was obtained by the comparison of sound field speech audiometry under two conditions: the patient facing the loudspeaker and the patient turned with his poor ear directed toward the speaker. The drop in discrimination scores under the second condition warranted the recommendation for a CROS. A follow-up test disclosed that the CROS unit benefited this patient substantially.
Marvin R. Navarro, Douglas O. Vogelson. An Objective Assessment of a CROS Hearing Aid. Arch Otolaryngol. 1974;100(1):58–59. doi:10.1001/archotol.1974.00780040062012