[Clinical and experimental studies of Stenger's experiment with speech]

A speech Stenger test by the numeral words of the German "Freiburger" test material (DIN 45621) has been conducted in 46 cases of suspected pseudohypacusis. Positive Stenger was produced by 30 patients (65%). 20 patients were sent from an otorhinolaryngologist with the diagnosis of inexplicable hearing loss and 16 of them (80%) showed a positive Stenger test. 10 (30%) of the 30 Stenger-positive patients get previously a CT and/or a MRT to exclude an acoustic neuroma. The pseudohypacusis was pretended in 56.7% to the right ear. The interaural difference of the speech level for full lateralisation is 10 dB. The sound level if the percentage of repeated words decreased, was higher in only 56.7% compared with the sound level on the ear with better hearing. 73% of the positive speech Stenger test showed that the percentage of the repeated numeral words did not drop immediately from 100 to 0%; we noticed intermediate values. To understand these better we initiated lateralisation tests in normal hearing people. In a second experience they were asked to simulate unilateral deafness. The interaural difference of the speech level in the Stenger test with simulated unilateral deafness was about 4 dB less than with normal hearing. Concentration to one ear might have some influence on the interaural difference of the speech level that leads to full lateralisation. All persons attained intermediate values and it was shown that all repeated words were heard in the direction of the normal hearing ear.