The contralateral ear in acoustic tumors and hearing conservation

Abstract
Hearing conservation in acoustic tumor surgery is an admirable goal and a logical extension of micro neurotologic surgery, but ideal candidates for conservation are few, and attempts to preserve hearing in those few fail in about half of all cases. Conserved hearing most often falls far beyond a range that will provide binaural function and is, therefore, of questionable use. The problem of hearing conservation in acoustic tumor surgery is rationally approached based upon the implications of the total presurgical overview, particularly with reference to age, general health, tumor size, and especially hearing in the tumor ear, the contralateral ear, and interaural relationships. Technical considerations, the morbidity and mortality, and, finally, probability factors are reviewed from the literature. The patient's consideration regarding potentials for hearing conservation, his need for conservation, and alternative options are discussed. Rehabilitative options for unilateral hearing impairment are discussed. A review of the amplification requirements of 45 acoustic tumor patients — S or more years postoperative — indicated that three-quarters had normal hearing in the contralateral ear, 24% of whom required CROS amplification; 67% of the remaining quarter had mild to moderate hearing losses and were effectively wearing BiCROS aids. None were rehabilitated with monaural aids; 20% of the entire group studied had demonstrated some degree of additional hearing loss in the non-tumor ear since surgery.