Objective To know the position and shape of implanted electrode array with plain X-ray after cochlear implantation. Methods According to the Cochlear View developed by Xu plain X-ray was taken postoperatively to obtain the best view of electrode array. Results The Medical imaging of plain X- ray taken before switching on or following the concerning of the performance could assist in the detection of electrode arrays in improper position, partial insertion or bending inside the cochlea. It helped audiologists to make decisions to switch off affected electrodes for the optimization of the program, if functioning electrodes were insufficient and recipients failed. Conclusion It is recommended to conduct post-operative X-ray examination routinely for cochlear implant recipients. Audiologists should be able to use medical imaging to identify the position of intra-cochlear electrodes and apply the information to guide the mapping work.

Objective Event related potentials (ERP), especially mismatch negativity (MMN), as index, was utilized to study the processing of Chinese tones recognized by cochlear implant (CI) users and normal hearing subjects. Methods The auditory materials were Chinese words with four tones consisting of three different oddball blocks. The ERP and MMN of CI users and normal hearing subjects were recorded and analyzed in relation to the discrimination of those tones as tested. Results The ERP and MMN of CI users and normal hearing subjects were presented. The MMN of CI users includes two negative waves: the first negative wave (MMN1) occurred approxi-mately 100 ms, and the second wave (MMN2) at 300 ms. The MMN of normal hearing subjects includes two nega-tive waves too: the first negative wave (MMN1) occurred approximately 150 ms, and the second wave (MMN2) al-so at 300 ms. The MMN1 peak latency of CI users was obviously shorter than that of normal hearing subjects and the MMN2 peak latency of CI users shorter than that of normal hearing subjects too, but the difference of MMN2 peak latency between CI users and normal hearing subjects was not as significant as that of MMN1. Conclusion In the preattentive stage, CI users could process Chinese tones as normal hearing subjects, but compared with the pro-cessing of normal hearing subjects, there are some differences in the processing of CI users.

Objective The purpose of this paper is to study the variations of the bone conduction hearing in the patients with chronic suppurative otitis media complicated by bone conduction deterioration after tympanoplasty and to analyze the relative factors. Methods In 54 cases (61 ears) of decreased bone conduction thresholds associat-ed with chronic suppurative otitis media, reviewed retrospectively were the data before the operation and during the follow-ups from 3 to 27 months. The bone conduction thresholds at 0. 5,1, 2 and 4 kHz were studied in relation to the courses of disease, the complications of cholesteatoma, the operation procedures and the reconstructions of os-sicular chains before and after surgeries. Results Before operation the most obvious hearing loss of bone conduction was found at 4 kHz in 61 ears, while after operation the average bone conduction hearing at the 4 frequencies was improved at different degrees with the most at 2 k Hz. Thirty-two of 61 cases (52.50%) were found to have their hearing improved at least by more than 10 dE at two frequencies without any deterioration at the 4 frequencies. Con-clusion The factors of the duration of disease and complications of cholesteatoma are obviously not related to the improvement of hearing after operation. A patient with reconstruction of ossicular chain is markedly superior to one without the reconstruction in improvement of hearing. When the auditory ossicular chains and functions of the oval and/or round windows are damaged, the bone conduction hearing can be affected accordingly. However the hearing of some cases will be improved after tympanoplasty. Also, the possible improvement is also related to different sur-geries in treating patients with middle ear infections.

Objective This paper is to explore the relationship between the placement of the bone oscillator and bone-conducted thresholds to ASSR stimuli in adults with normal hearing and to investigate the amplitude and the threshold differences to bone-conducted auditory steady-state responses (BC-ASSR) stimuli between single - and multiple-stimulus conditions. Methods Two groups of subjects were selected with 0. 5, 1, 2 and 4 kHz brief tones repeated at the rate of 77, 87, 93 and 101 Hz using a B-71 bone oscillator either in single- or multiple ted no significant differences between mastoid and behind-the-ear placements. The mean and standard deviations of bone-conducted behavioral thresholds to ASSR stimuli at 0.5, 1, 2 and 4 kHz were 62.6±4.8,47.1±4.8,46.8cant difference between the two conditions while the mean and standard deviations of BC-ASSR thresholds at 0.5, 1, 2 and 4 kHz were 96.7±9.7,70.3±11.6,60.6±7.4,52.8±7.2 dB re: 1μN (ppe), respectively. Conclusion The behavioral bone-conducted thresholds to ASSR stimuli with mastoid and behind-the-ear placemen yielded no significant differences. When the stimuli intensity was 50 dB nHL, the amplitudes in single-stimulus condition were significantly higher than those to multiple-stimulus condition. There were no significant differences for BC-ASSR thresholds between single- and multiple-stimulus condition.

Objective To assess the feasibility of adenoviral vectors mediate cochlear gene transfer by postau-ricular microinjection through the round window membrane in mouse. Methods Twelve 5-week old C57BL/6J mice were selected for the study: 8 were implanted with Ad-EGFP by postauricular microinjection through the round window membrane, and 4 with artificial perilymphatic fluid. On postoperative days 5 and 14, the animals were sac-rificed and the surface preparation of cochleae was observed. Results Two animals died after operation. Bright green fluorescence in the cochleae was observed in Ad- EGFP groups. Gene expression on day 14 after operation was higher than that on day 5. However, the control group was free of fluorescence. Oonclusion The postauricular route of the cochlear gene transfer in mice is simple to operate with little side-effect. The technique of transgenic delivery into the inner ear through RWM by mieroinjection is feasible and effective.

Objective The purpose of this study is to compare the most comfortable levels and neural re-sponse imaging threshold between children of cochlear implants with large vestibular aqueduct syndrome and normal inner ears. Methods Thirty-eight implanted children participated in this study and were divided into two groups. Group A consisted of 32 patients with normal inner ears and group B 6 patients with radiographically proven large vestibular aqueduct syndrome. All of the patients were the recipients of the cochlear implants by Advanced Bionics. The initial time for the first programming session was approximately one month after surgery. The psychophysical tests included M- level tests. Programming techniques used in the test were suitable for the age of patients. Sound-Wave 1.4 software was used to test tNRI. Results Using the rank sum test, M-level and tNRI of electrode 3,7,11 and 15 did not differ significantly between group A and B(P>0. 05). Conclusion The parameters of mapping are not significantly different between the implanted children with large vestibular aqueduct syndrome and normal inner ear. The management and procedures of mapping used to the subjects with normal inner ear can be applied to the children with large vestibular aqueduct syndrome.

Objective To investigate the mechanisms of early sensorineural hearing loss of diabetic rats. Methods The diabetic model for rats was established. Every rat was checked with ABR and DPOAE before and af-ter treatment . After 14 days , the blood glucose, blood fat, SOD, GSH-Px and MDA were measured. Results For the model group, the rats" blood glucose and fat increased while the GSH-Px was reduced more than the con-trol group. The response amplitudes of DPOAE decreased at 4 000 Hz and 8 000 Hz(P<0. 05). Conclusion The damage to the hair cells caused by the affected metabolism is considered as the culprit of the sensorineural hearing loss and the changes of DPOAE took place earlier than that of ABR, thus becoming useful in detecting early hearing loss of the diabetic patients.

Objective To study the protective role against cisplatin-induced ototoxicity by using radix astra-gali in rats. Methods Forty rats were randomly divided into four groups. Group A received saline as controls. Group B received radix astragali. Group C received injection of cisplatin(4 mg/kg) as experiments for 6 days. Group D received both radix astragali (5 g/kg) and cisplatin (4 mg/kg). Distortion product acoustic emission (DPOAE) was applied to each rat before and 7 days after cisplatin injection. All the animals were sacrificed on the 7th day. Half of the cochleas were observed by frozen section and the apoptosis of hair cells was detected by TUNEL meth-od. Scanning electron microscopy was utilized to evaluate the cochlear morphology of the other rats. Results The DPOAE amplitudes of Group C decreased significantly compared to the group A and group B(P<0.01). The dam-age and apoptosis of hair cells were noted in the group C and group D, while the hair cells of group A and group B showed no sign of apoptosis or damage. Compare to experimental group , the DPOAE amplitudes of group D were higher, and the damage and apoptosis of hair cells were significantly lower(P<0.05). Conclusion This study sug-gests that radix astragali can effectively reduce cisp[atin ototoxicity.

Objective To investigate the different expression levels of Na+ - K+ - 2Cl- co- transporter NKCC1 mRNA in the cochlea of rats after sodium salicylate injection and to explore the mechanism underlying the change of outer hair cells, induced by different salicylate administration. Methods Twenty-four normal adult rats were randomly divided into four groups with six rats in each group. Rats in control group,did not recieve sodium sa-licylate injection. The other three groups were acute group,chronic group,and recovered group according to the dif-ferent doses of sodium salicylate. The fluorescence quantitative PCR method was used to detect the expression levels of NKCC1 mRNA in the rat cochleas of the four groups. Results NKCC1 mRNA was expressed in all of the four groups. After sodium salicylate injection, the expressions of NKCC1 mRNA in chronic and recovered group were higher than that in control group(P<0.05). While the expression of NKCC1 mRNA in acute group was lower than that in control group(P(0. 05). Conclusion The expression of NKCC1 mRNA in the normal cochlea indicates that NKCC1 may play an important role in the maintenance of Cl- in the endolymph of the cochlea. The alteration of NKCC1 mRNA expression caused by sodium salicylate injection may lead to the change of the outer hair cell electro-motility.

Objective To investigate the range of normal values of tympanometry of guinea pigs and the possible differences associated with genders and ears. Methods Included in this study were 40 guinea pigs with nor-mal hearing and no ear diseases. Under the anesthetized condition, each guinea pig's tympanogram was recorded, and their values were studied associated with different genders and ears. Results The tympanograms thus obtained were all type A. For all the tympanograms of 80 ears, the equivalent canal volume was about 0.09±0. 02 ml, the static compliance was 0.10 ±0.03 ml, the gradient was 0.14 ±0.06 ml, and the pressure of the peak admittance was -99.44±75.06 daPa . The findings of different gender groups yielded statistic differences in the values of e-quivalent canal volume (P=0. 012) but not in static compliance, gradient and peak admittance pressure (P>0. 05). Typical tympanograms were recorded for the both ears in 40 guinea pigs at the same time. There were no binaural differences (P>0.05). Conclusion The results show significant differences in the equivalent canal volumes be-tween male and female guinea pigs. These tympanograms may serve as a guide to detect middle ear dysfunctions in guinea pigs.