Evoked Response Audiometry: Influence of Somatosensation

Abstract

Averaged vertex response thresholds evoked with the oscillator on the mastoid process and tibia in patients deaf since birth or early childhood, patients with sensorineural hearing loss acquired during adulthood, and subjects with normal hearing were compared and the following conclusions were reached:

(1) This study provided the first objective documentation of the pseudoauditory nature of the low-freqency air-bone gap. This vibratory phenomenon is acute in individuals who have been deaf since early childhood.

(2) Evoked response audiometry (ERA) demonstrated a potential hazard in testing deaf children. If ERA shows a low-frequency air-bone gap, one should suspect that the response is of vibratory origin. Confirmation of the origin can be obtained by recording responses evoked by tibial stimulation.

(3) ERA bone-conduction thresholds accurately correlate with conventional bone-conduction thresholds.

Key Words:

• Electric Response Audiometry
• Sensorineural hearing loss
• Bone-conduction thresholds
• Childhood deafness