ABSTRACT
Objective To investigate the relationships between tinnitus masking curve types and tinnitus re-sidual inhibition in the patients at different ages with normal hearing ,mild ,moderate severe hearing loss .Methods The minimum masking levels and residual inhibition of 335 patients with normal hearing ,mild to medium ,and mod-erate to severe hearing loss were tested and analyzed using the method of psychological acoustics .Results Ages and the duration of residual inhibition had a corresponding relationship :the 19～30 years old group had corresponding relations with 0～40 seconds of residual inhibition ,while the 31～50 years old group with 81～100 seconds of resid-ual inhibition ,and the 50～63 years old group with 101～200 seconds of residual inhibition ,respectively .The 31～50 years old group and 51％ ～80％ residual inhibition had a corresponding relationship ;0％ ～30％ residual inhibi-tion group and parallel type of tinnitus masking curves had a corresponding relationship ,31％ ～50％ residual inhibi-tion group and separation type of the tinnitus masking curves had a corresponding relationship ,the groups of 51％ ～80％ and 81％ ～100％ residual inhibition with the types of convergent and overlapping tinnitus masking curves had corresponding relationship ,respectively .Conclusion There were different characteristics of tinnitus masking patients at different ages with different levels of hearing loss .The older people are ,the better effects and longer time of residual inhibition are .Those tinnitus patients with the tinnitus masking curve of convergent type and overlapping type showed a better tinnitus masking effect than the others .
ABSTRACT
OBJECTIVE@#To study the microanatomy by endoscope-assisted via retrolabyrinthine approach.@*METHOD@#Nineteen cadaveric heads fixed with formalin were dissected in our study. The data that endoscope could be extent and the distance between the important point were measured. By simulated the retrolabyrinthine approach, endoscope was placed to observe the nerves and vessels, the distance between nerves and the central point of the anterior edge of sigmoid sinus were measured.@*RESULT@#The distance from the inferior margin of petrous ridge to the upper bound of endolymphatic sac was (9.93+/-1.52)mm; and from superior margin of petrous ridge to the inferior margin common bony crus was (4.64+/-0.91)mm;and from the intersection of posterior semicircular canal to the anterior wall of sigmoid was (7.85+/-1.47)mm on the left, and (5.69+/-1.68)mm on the right. The distance from inferior margin common bony crus to the anterior wall of sigmoid was (13.9+/-1.71)mm on the left, and (11.31+/-2.03)mm on the right. The trochlear nerve and abducent nerve could be observed under endoscope. The relationship between the trigeminal nerve, acoustic nerve and the vessels could be identified clearly. The distance from the central point of the anterior edge of sigmoid to the roots of the trigeminal nerve, facial nerve, vestibulocochlear nerve and glossopharyngeal nerve were (29.88+/-2.77) mm, (32.04+/-2.04) mm, (29.17+/-1.65) mm, (35.49+/-1.53) mm respectively.@*CONCLUSION@#The visual field of the cerebellopontine angle appear wider by the endoscope assisted retrolabyrinthine approach. Nerves, vessel, internal acoustic pore, jugular foramen region can be clearly seen. Some minimal invasive surgery can be done by this approach.