Localization in auditory space

THE CAPACITY to localize sound stimuli has been employed by one of us in bedside neurologic examination for many years. Initially, this method was used to confiim a visual field defect wherein an incapacity to localize an object, by touching it, had been demonstrated. I t became apparent, however, that the inability to locate manually an auditory stimulus way frequently noted in the absence of visual field deficit. This phenomenon was reported in two separate communications by Sanchez-Longo and his colleagues.1,~ In the first report, they dealt exclusively with temporal lobectomy patients and, in the second, with a variety of intracranial lesions. Their method, finding.;, and conclusions will be discussed later. We studied 204 subjects systematically in an attenipt to determine the relative incidence of localization defect in auditory hemispace. They may be divided as follows: [l] the “noimal,” [ 21 patients with neurologic disease localized below the tentorium, and [3] patients who had evidence of supratentorial dysfunction. In connection with the last group, clinical, angiographic, pneumoencephalographic, operative, or postmortem evidence was used to determine whether one or both cerebral hemispheres contained structural changes. We were less concerned with the exact localization of the defect within the hemisphere, but as will be shown, some evidence did accrue as to gross localization in a significant number of patients.