Bekesy test results in patients with eighth-nerve lesions. Forward reverse- and fixed-frequency tracings

Sweep-frequency Bekesy tracings, both forward (low to high frequency) and reverse (high to low frequency), as well as fixed-frequency tracings, were obtained from 18 patients who had eighth-nerve tumors (subsequently confirmed surgically). In general, reverse-sweep frequency tracings revealed greater adaptation for continuous tone stimuli than did forward-sweep frequency tracings. However, if a search for excess adaptation (greater than 20 dB) is the sole purpose for administering Bekesy audiometry to a given patient, then fixed-frequency tracings yield adequate differential information.