Patients with left or right anterior temporal lobectomies show severe deficits on the ear contralateral to the lesion in responding to dichotic speech stimuli. One patient with a left and one with a right anterior temporal lobectomy were tested on a dichotic pursuit auditory tracking task. There were no severe performance deficits that would have indicated difficulty in processing either pure tone stimulus.
The resected areas were apparently not necessary for relatively efficient processing of these simple nonspeech stimuli, either because other parts of the damaged hemisphere were sufficient for task performance or because ipsilateral auditory transmission pathways can be used in this task. Both patients showed a speech-related right ear advantage for the jaw generated tone but not for the hand generated tone.