Objective　To explore the effects of treatment and mechanism of sodium salicylate on blast deafness. Methods　Guinea pigs were divided into blast group, blast plus sodium Salicylate group and sodium solicylate group. The animals in the blast group were exposed to blast average peak pressure 176.7 dB(SPL); sodium salicylate was injected IP 400 mg/kg,1/d. Monitoring ABR threshold, the value of MDA of and counting the number of hair cells on the cochlea preparation, SEM for hair cells was observed. Results　The ABR threshold shift in the blast group was 46.75±13.56 dB，38.0±12.4 dB,35.5±10.67 dB，41.5±12.57 dB,33.75±8.42 dB, post-blast 1 d，3 d，1 w，2 w,4 w respectively. And that of the blast plus sodium salicylate was 46.65±11.7 dB，38.25±9.52 dB,30.5±9.17 dB,30.0±9.17 dB,23.0±6.57 dB. The two groups differed significantly at 1 w，2 w，4 w(P＜0.05). The value of MDA differed significantly at 2 w,4 w(P＜0.05). And the hair cells lost also differed significantly. It was observed that sodium salicylated can raise the ABR thresbold temporarily 24 hrs during simple sodium salicylate adminastration. However it recovered 14 hrs after the injection.Conclusion　Sodium salicylate can partially attenuate the hearing loss caused by blast. It is probable that sodium salicylate can clear peroxicative produced during blast and therefore protect hair cells and make hearing loss partially recover.

Objective　To quantify the characteristics of the auditory brainstem responses(ABR) in the normal newborns, in order to provide a data for newborn hearing screening. Methods　The ABR to click stimuli was investigated in a group of eighty normal newborns aged from 3 to 8 days and compared to those observed from the normal hearing youths. Results　Wave, Ⅰ,Ⅲ and Ⅴ were identifiable in all of 160 ears at 130 dB pe-SPL. The threshold of wave Ⅴ to click stimuli was 61.94±6.87 dB peSPL, significantly higher than that in adults. Both latencies for wave Ⅰ,Ⅲ and Ⅴ and interwaves latencies Ⅰ-Ⅲ,Ⅲ-Ⅴ and Ⅰ-Ⅴ were significantly tonger than those for the adults under identical test conditions. The ratio of interwaves latency Ⅲ-Ⅴ to Ⅰ-Ⅲ for normal newborn was 0.71±0.12, statisitically smaller than that in adults. Conclusion　Click level 70 dB peSPL appeared to be a feasible criterion of threshold of ABR for newborn hearing screening. There were no significant effects of sex and ear in newborn hearing screening. The auditory system of the newborns was not equally mature. The neurological system is the primary source of differences between newborns and adults.

Objective　To obtain the normal ranges of different parameters in static posturography.Methods　Different parameters' values of 117 normal persons (10～19 years old) were detected by static posturography while they were in opening and closing eyes situations. Results　The mean values of different parameters in opening eyes situation are significantly lower that in closing eyes situation(P＜0.01). The values from the male and the female demonstrate no significant difference, values from 10～19 years old group and 70～79 years old group are significantly higher than from 20～69 years old group(P＜0.01). Conclusion　The static posturography is a perfect measure to analyze and evaluate the balance ability of human body in exact quantification, and could be one of the routine clinic tests, supplying quantificational, intellective and facile method for diagnosis and evaluation of dizziness and balance ability.

Objective To investigate the characteristics of acoustic parameters and spectrograph of organic and functional voice disorder and evaluate the value of acoustic analysis technique by computer in the differential diagnosis of voice disorder. MethodsThe voice signals of sustained vowel "a" were measured with a microcomputer (Dr.Speech Software) in 70 healthy adults, 60 patients with varying organic diseases of vocal cords and 50 cases with functional voice disorder. The acoustic parame ters (jitter, shimmer, NNE) and spectrographic characteristics were analyzed and compared. ResultsIn 60 patients with organic diseases of vocal cords, all the acoustic parameters were significantly increased and the spectrograph showed irregularity,breakage or lack of harmonic waves and formants, and increase of noise. In 50 cases with functional voice disorder, the shimmer and NNE were significantly increased but the jitter was usually normal. The spectrograph showed pathologic changes of harmonic waves and formants in middle and high frequencies. The normal acoustic characteristics could be found in 94% (47/50) of the patients with functional voice disorder. ConcluisionThe acoustic analysis by computer technique is of value in the differential diagnosis of or ganic and functional voice disorder.

ObjectiveTo study the relation of phonation and respiration in normal subjects. MethodsUsing Aerophone Ⅱ Model 6800 and Visipitch 6097, vital capacity was recorded first , then the simultaneous phonation volume, maximum sustain phonation time,mean airflow rate,sound pressure level and average pitch were recorded in order to induce the relation of phonation and respiration in normal subjects. ResultsThere was a linear correlation between phonation volume and vital capacity. Maximum sustain phonation time varied with changes of mean airflow rate and phonation volume and mean airflow rate varied little in different subjects and had no relation with average pitch and sound intensity. ConclusionMaximum phonation time, the mean airflow rate and ratio of phonation volume to vital capacity can be used as indicator in clinical application.

ObjectiveTo search for the optimum external masking time and tonal models for patients with tinnitus.MethodsTwenty-seven patients with cochlear tinnitus were selected respectively from three different out-patients departments and divided into three groups. Nine patients in every group were treated with different masking parameters according to factorial design which had three masking noises, i.e. narrow band noise (NBN), wide band noise (WBN), speech noise (SN),and three masking time ranges, i.e. 15,30,45 minutes. The results before and after treatment were compared and analysed with analysis of variance (ANOVA). ResultsThe treatment effect when masking for 15 minutes was worse than that for 30,45 minutes, but there was no difference between 30 and 45 minutes. The NBN had the best effect when tinnitus signal was single, the WBN was effective for tinnitus with multiple sounds. ConclusionNBN or WBN masking for 30 minutes showed better therapeutic effect.

ObjectiveTo investigate the expression of asubunit isforms of Na,K-ATPase in stria vascularis of guinea pig, and the effect of gentamicin on it. MethodsThe expression of a subunit isoforms of Na, K-ATPase in stria vascualris of guinea pig and its change after gentamicin exposure were identified immunocytochemically using the specific mouse antibodies a gainst the α1 ,α2 and α3 subunits of rat Na,K-ATPase. ResultsAll marginal cells,intermediate cells and basal cells of stria vas cualris showed positive expression of α1 isoform and negative expression of α2 and α3 isoforms. The immunostaining of α1 isform was attenuated significantly after gentamicin esposture. ConclusionGentamicin significantly inhibits the expression of Na, K-ATPase α1 subunit isoform of the stria vascularis, sequentially inhibits the activity of Na,K-ATPase.

ObjectiveIn order to investigate the effects of shock wave on atrial natriuretic peptides immunoreactivity in the stria vascularis and hair cells of cochlear and correlation of auditory threshold shift,to study the mechanism of deafness caused by blast trauma. MethodsAfter shock wave, different groups of guinea pigs were studied by ABC immunohistochemistry, image analysis and auditory brainstem response. ResultsANP - IR optic density in experimental group was higher than that of control in the stria vascularis and inner hair cells. The change of ANP- IR optic density was directy correlated with ABR threshold shift (r2 =0.9185. P2＜0.05). There was no change of ABR and ANP - IR optic density on outer hair cells. ConclusionThe change of ANP in the stria vascularis may be a compensatory mechanism to heating lose caused by shock wave; ANP in inner cells may be a pathological manifestation of shock wave. The changes of ANP - IR in outer cells may be a false appearance, it was the shock wave which lead to outer cells ANP running off.

ObjectiveTo define the components of membranous labyrinth proteins which take part in the development of autoimmunity in experimental animals with autoimmune inner- ear disease(AIED). MethodsAn animal modee of AIED was es tablished by using homologous crude inner ear antigen to immune the guinea pig. The autoantibodies against inner ear antigenin the sera of animals were examined by immunoblotting assay. ResultsThe components of membranous labyrinth proteins were very complicated, which had five main bands in electrophoresis; most of immunized animals had only developed two sorts of autoantibod ies which were anti-68 kD and 136 kD membranous labyrinth proteins. There was no positive reaction in sera of control animals. Conclusion This results showed that the immune reactions against the 68 kD and 136 kD proteins of membranous labyrinth may be autoimmune bases for AIED in animals.

Objective To explore the feasibility and effectiveness of otoacoustic emission (OAE) in hearing screening for preschool children .Methods A total of 616 preschool children aged 3～6 (mean age 4 .6 years old) were included in this study .All the subjects received transiently evoked otoacoustic emission (TEOAE) test by trained personnel .The children who failed the hearing screening received diagnostic examination in the hearing ex-amination center .Results Of 616 children ,66 (10 .71％ ) failed the hearing screening and 16 children received audi-ological assessment .In these 16 children ,8 had otitis media with effusion (5 with mild conductive hearing loss ) ,5 had impacted cerumen ,3 had normal hearing ,and none had sensorineural hearing loss .Conclusion OAE can be used effectively in the hearing screening for preschool children .But how to improve the referral rate of children who failed the hearing screening needs further discussion .