The effect of increase in blood glucose level on hearing loss

Abstract Objective: Previous studies have shown that hearing function is also vulnerable to the effects of diabetes mellitus which can be shown by brainstem auditory evoked potential and distortion product otoacoustic emission recordings. This study aimed to investigate the changes of brainstem auditory evoked potential and distortion product otoacoustic emission in hyperglycemia and whether there is a relationship between reactive oxygen substances production and hearing deterioration in the rat model. Methods: 25 streptozotocin induced diabetic rats were divided into three groups: control, high blood glucose, and diabetes mellitus. Brainstem auditory evoked potential and distortion product otoacoustic emission were recorded, and thiobarbituric acid reactive substances levels were measured in the brainstem tissue. Results: At 8 kHz, the latencies of I, II, III, IV, and V brainstem auditory evoked potential waves in high blood glucose and diabetes mellitus groups were elongated, at 16 kHz, only these wave latencies of the diabetes mellitus group were prolonged compared with the control group. A significant decrease was also found in distortion product otoacoustic emission amplitudes at 4, 6, 8, and 10 kHz in the high blood glucose and diabetes mellitus groups compared to the control group. There was a significant increase in thiobarbituric acid reactive substances values due to the increase in blood glucose levels in the high blood glucose and diabetes mellitus groups compared to the control group. Conclusion: These results suggested that high blood glucose levels may cause hearing impairment not only in the diabetic state but also in the period of hyperglycemia before the onset of manifest diabetes mellitus and reactive oxygen substances may play an important role in the pathophysiology of diabetes mellitus. We suggest that regulating high glucose levels even before the onset of manifest diabetes mellitus may prevent hazardous effects on hearing function. Level of evidence: Level 3.

Esketamine may be an ideal substitute for ketamine during cochlear function measurement

The mixture of ketamine and xylazine is widely used for the auditory brainstem response (ABR) measurement. Esketamine is twice as potent as ketamine. Our objective was to assess the influence of esketamine in mice undergoing cochlear function measurement including ABR and distortion product otoacoustic emission (DPOAE) measurement. C57Bl/6J mice were treated with an equivalent dose of analgesia and received either a single intraperitoneal (ip) injection of 100 mg/kg ketamine and 25 mg/kg xylazine or 50 mg/kg esketamine and 25 mg/kg xylazine. Hearing thresholds, peak latencies of waves I and V, and DPOAE thresholds were recorded. Time to loss of righting and time to regain righting were also assessed. We found that hearing thresholds, the peak latencies of waves I and V, and DPOAE thresholds were similar between the two groups (all P>0.05). Time to regain righting was significantly shorter in the esketamine group (P<0.001) than in the ketamine group. We concluded that when using equivalent doses of analgesia, esketamine may be an ideal substitute for ketamine during cochlear function test.

Analysis of Distortion Product Otoacoustic Emissions in Hepatitis B Carrier and Chronic Hepatitis B Patients with Normal Pure Tone Findings / 听力学及言语疾病杂志

Objective To investigate the characteristics of distortion products otoacoustic emission (DPOAE) in hepatitis B carriers and chronic hepatitis B patients with normal pure tone results .Methods DPOAE was detected in 29 hepatitis B carriers (58 ears) ,30 chronic hepatitis B patients (60 ears)and 30 normal controls .The three groups had normal pure tone results .The detection rate and amplitude difference of DPOAE at 553～6250 Hz were compared between the two groups .Results The incidence of the DPOAE in HBV carriers for all the frequencies was higher than that in the chronic hepatitis B group ,but there was no significant difference (P>0 .05) .The level of the DPOAE in HBV carriers for all the frequencies was higher than that in chronic hepatitis B group ,and there were significant differences at 1105 ,1560 ,2211 ,3125 ,4416 ,6250 Hz (P<0 .05) ,and at 1560 ,2211 ,6250 Hz(P<0 .01) ,except at 553 ,783 Hz (P>0 .05) .Conclusion There is a potential loss of cochlear functions in the chronic hepatitis B group compared with the HBV carrying group .We suspect that the progress of liver disease is related to the potential hearing loss .

The Effect of Primary Levels and Frequencies on the Contralateral Suppression of Distortion Product Otoacoustic Emission

BACKGROUND AND OBJECTIVES: Changes in distortion product otoacoustic emission (DPOAE) caused by contralateral suppression (CS) allow the function of the auditory efferent system to be evaluated. Parameters affording maximum CS are preferred in terms of clinical application. Our objective was to evaluate the effects of primary levels and frequencies on DPOAE-mediated CS. SUBJECTS AND METHODS: Sixteen subjects with normal hearing participated. DPOAEs were recorded with and without contralateral acoustic stimulation; we delivered broadband noise of 65 dB SPL at f2 frequencies between 1,000 Hz and 6,727 Hz, at 8 pt/octave. The L2 was varied between 40 dB SPL and 80 dB SPL in 10-dB steps. RESULTS: L2 did not significantly affect DPOAE-mediated CS. Higher L2 levels significantly reduced the fine structure depth of both the baseline and suppressed DPOAE datasets. The amount of CS was greatly affected by the f2 frequency; lower and higher frequency ranges afforded significantly stronger suppression than did mid-frequencies within the studied range. CONCLUSIONS: Our findings suggest that DPOAE CS should be measured over a wide range of frequencies as the amount of CS seems to be highly dependent on f2. The use of a higher L2 level may be optimal when it is sought to evoke strong DPOAE-mediated suppression while simultaneously minimizing DPOAE fine structure. Our findings may assist in optimization of clinical procedures evaluating the integrity of the auditory efferent system.

Functional Significance of Medial Olivocochlear System Morphology in the Mouse Cochlea

OBJECTIVES: Baso-apical gradients exist in various cochlear structures including medial olivocochlear (MOC) efferent system. This study investigated the cochlear regional differentials in the function and morphology of the MOC system, and addressed the functional implications of regional MOC efferent terminals (ETs) in the mouse cochlea. METHODS: In CBA/J mice, MOC reflex (MOCR) was assessed based on the distortion product otoacoustic emission in the absence and presence of contralateral acoustic stimulation. High, middle, and low frequencies were grouped according to a mouse place-frequency map. Cochlear whole mounts were immunostained for ETs with anti-α-synuclein and examined using confocal laser scanning microscopy. The diameters of ETs and the number of ETs per outer hair cell were measured from the z-stack images of the basal, middle and apical regions, respectively. RESULTS: The middle cochlear region expressed large, clustered MOC ETs with strong MOCR, the base expressed small, less clustered ETs with strong MOCR, and the apex expressed large, but less clustered ETs with weak MOCR. CONCLUSION: The mouse cochlea demonstrated regional differentials in the function and morphology of the MOC system. Strong MOCR along with superior MOC morphology in the middle region may contribute to ‘signal detection in noise,’ the primary efferent function, in the best hearing frequencies. Strong MOCR in spite of inferior MOC morphology in the base may reflect the importance of ‘protection from noise trauma’ in the high frequencies.

The Effects of Different Selective Attentions on Amplitudes of Distortion Product Otoacoustic Emissions / 听力学及言语疾病杂志

Objective To investigate the effects of different selective attention on the amplitudes of distortion product otoacoustic emission (DPOAE) .Methods DPOAE measurements were performed in 30 young adults (60 ears) in no task (baseline) ,visual selective attention and auditory selective attention ,respectively .The suppression of DPOAE amplitudes were observed in different selective attentions .The visual selective attention was to counter the number of letter Q presented on computer screen .The auditory selective attention was to counter the number of 2 .0 kHz toneburst in the insert earphone .Results Visual and auditory selective attention both decreased the DPOAE amplitudes in mid - low frequencies (0 .75 ~ 2 .0 kHz) .The suppression effects of visual selective attention were significant stronger than that of auditory attention in 0 .75 ~ 1 .0 kHz .The suppression amplitudes were 8 .54 ± 4 .76 and 5 .27 ± 2 .32 dB at 0 .75 kHz ,respectively .They were 7 .66 ± 5 .22 and 3 .22 ± 2 .15 dB at 1 .0 kHz ,re‐spectively .There were significant differences between the two selective attentions suppression (P< 0 .05) .Conclu‐sion Visual and auditory selective attention can both decrease the DPOAE amplitudes .The suppression effects of visual selective attention were significant stronger than that of auditory attention .

Analysis of Distortion Product Otoacoustic Emission in Pilots Under Physical Examination for Modification to Equipment of High Performance Aircraft / 听力学及言语疾病杂志

Objective To evaluate the hearing function of pilots under physical examination for modification to equipment of high performance aircraft,using pure tone audiometry(PTA) and distortion product otoacoustic emission(DPOAE).Methods Analyzed were all the results of PTA and DPOAE of 75 pilots (150 ears) which accepted physical examination for modification to equipment of high performance aircraft in our department from March 2008 to February 2009.75 cases were divided into two groups according to their flight time.The difference between these two groups was studied.Results According to the Equipments of Physical Constitution for Flying Persons of Air force,PLA,all 75 pilots passed the ENT assessments as being qualified for flying.Of all 150 ears,abnormal DPOAEs were obviously higher than that of abnormal PTA tests.128 ears had normal PTA results.92 ears had normal DPOAE results.36 ears (27.6&) showed abnormal DPOAEs at one or more frequencies,especially at 1,3 and 4 kHz.22 ears had abnormal PTA results.20 ears had noticeable V or U shaped thresholds at 3 kHz and/or 4 kHz.The DPOAE amplitudes showed similar curves.The other two ears showed depressions at all frequencies,in both PTA and DPOAE tests.No statistically significant difference was found between the two groups in DPOAE.But statistical difference was found in DPOAE at 4 kHz compared with other frequencies.No statistically significant differences were found between the two groups in DPOAE amplitudes at 1,2,3 and 4 kHz.but at 6 and 8 kHz.Conclusion The application of DPOAE test helped find pilots who were on the early stage of noise-induced hearing loss.These pilots were the most important objects for us to follow up.

The Application of 1000 Hz Probe Tone Tympanometry to Infants / 听力学及言语疾病杂志

0.05).Conclusion The peaked tympanogram of 1 000 Hz probe tone tympanometry in infants indicates normal results while flat tympanograms and other irregular shapes are abnormal.The middle ear functions are affected with flat tympanograms.The 1 000 Hz probe tone tympanometry is a valuable diagnostic tool to evaluate the middle ear functions in infants while 226 Hz probe tone tympanometry is considered inappropriate for infants.The 1000Hz tympanometry is more sensitive than ABR Wave Ⅰlatency and DPOAE responses.

The Influence of Long-Term Sound Conditioning on the Physiology of Outer Hair Cells / 听力学及言语疾病杂志

Objective To investigate the influence of long-term sound conditioning on the physiology of outer hair cells.Methods Twenty healthy guinea pigs were exposed to a broadband noise for 14 days consecutively at the level 90 dB(A),8 h/day.The DP-gram and input/output(I/O)function(1~8 kHz)were measured at pre-conditioning,fourteen days conditioning,seven days post-conditioning and fourteen days post-conditioning,respectively.Results The results of DP-gram measurements demonstrated that long-term sound conditioning could enhance the DPOAE amplitudes within low frequencies(1~3 kHz,especially 5.0 dB at 2 kHz and 7.5 dB at 3 kHz,P

Effects of the Acute Sodium Salicylate Injection on the Distortion Product Otoacoustic Emissions of Awake Guinea Pigs / 听力学及言语疾病杂志

Objective To study the change and the characteristics of distortion product otoacoustic emissions (DPOAE) of awake guinea pigs with the acute injection of sodium salicylate, and to investigate the ototoxicity of sodium salicylate to OHC. Methods With CELESTA 503 otoacoustic emission analyzer, DPOAE including DP-gram and DP-I/O function of awake guinea pigs were recorded.DPOAE were measared before and 2,4,8 h after acute injection of sodium salicylate or saline respectively. The data were analysed with SPSS 10.0.Results Acute sodium salicylate injection mainly caused the DPOAE amplitude and the I/O slope to reversibly decrease and increase respectively. The changes were largest 2 h after injection, and almost returned to normal level 8 h after injection. The differences between certain outcomes of DPOAE after and before injection were significant (P

Effects of infrasound on the auditory function of guinea pigs / 中华物理医学与康复杂志

Objective To observe the effects of exposure to infrasound on auditory function of guinea pigs as reflected by the brain stem response (ABR) and distortion product otoaeoustic emission(DPOAE).Methods Seventy-two Guinea pigs were used in this study,of them,12 served as controls and 60 were divided into 2 experi- mental subgroups.ABR and DPOAE were detected after exposure to infrasound stimulation at 16 Hz,90 dB or 16 Hz,130 dB for 2 hours a day for 1 ,7,14,21 and 28 days.Results The threshold of ABR after exposed to infrasound at 16 Hz,90 dB in 1 day and 28 days was higher than the controls (P0.05),but significant difference was observed with 16 Hz 130 dB infrasound exposure on the 21st and,28th days when compared with the controls (P

The Efficacy of the Hearing Threshold Level at 3 kHz I/O Curve in DPOAE in Screening the High Risk Neonates in NICU / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Universal infant hearing screening has been recommended by the National Institutes of Health. Although the distortion-product otoacoustic emissions (DPOAE) hold promise as a screening technique, the validity oftheir input/output function curve (I/O curve) in the screening of neonates has not been fully investigated. The aims of this study were to determine the efficacy of the I/O curve as a hearing screening test and to investigate the prevalence of sensorineural hearing loss (SNHL)(moderate to severe degree) in high risk neonates. MATERIALS AND METHOD: A total of 69 ears of 35 infants at risk for hearing loss were tested with both DPOAE and auditory brainstem responses (BR). Auditory brainstem response results were used as the standard for hearing. The hearing threshold level at 3 kHz in I/O curve and the amplitude of distortion product in the DP audiogram were calculated and compared with the results of ABR. Neonates whose hearing thresholds were worse than 60 dB in the I/O curve were regarded as 'test-positive' and neonates whose hearing thresholds were worse than 60dB in ABR were regarded as 'disease-positive'. The sensitivity and the specificity of each test were calculated and the correlations between the response of each test and ABR threshold were also studied. RESULTS: The prevalence of SNHL in neonates in the SNUH neonatal intensive care unit was 5.79%. The sensitivity and specificity of the screening test using the I/O curve were 100% and 63.1%, respectively. The test using the DP amplitude for SNHL showed the sensitivity of 100% and the specificity of 18.46%. This was much lower than that of the screening test using the I/O curve. There was a positive correlation between the I/O threshold and ABR threshold (r=0.43), but there were no statistically significant correlations between the DP amplitude and the ABR threshold nor between the DP amplitude and the I/O threshold. CONCLUSIONS: The test using the I/O threshold in DPOAE is suitable for the screening of the SNHL in neonates with high sensitivity and relatively high specificity. Moreover, the I/O threshold could predict the audiometric threshold more correctly than the DP amplitude could.

The Application of Distortion Product Otoacoustic Emission to Assessing Children with Otitis Media with Effusion / 听力学及言语疾病杂志

0.05),but the difference was significant at high frequency(P

Study of the Antagonist Effects of Sodium Salicylate on the Cisplatin Induced Hearing Impairment in Guinea Pigs / 听力学及言语疾病杂志

Objective To investigate the antagonist effects of sodium salicylate(NaSA) on the cisplatin(CDDP) induced hearing impairment in guinea pigs.Methods 60 guinea pigs were randomly divided into four groups: ①CDDP +NaSA(50 mg/kg) group,②CDDP +NaSA(100 mg/kg) group,③CDDP +NaSA(150 mg/kg) group and ④CDDP +NS(normal saline) control group.Auditory brainstem response(ABR) and distortion product otoacoustic emission(DPOAE) were used to evaluate their effects on hearing threshold and DPOAE amplitudes.Results The ABR responses of groupsⅠ,Ⅱ and Ⅲ were significantly lower than in the control group(P0.05).The ABR responses for group Ⅰ were significantly higher than group Ⅲ(P

The Latency of Distortion Product Otoacoustic Emissions in Normal Ears / 대한이비인후과학회지

Distortion-Product Otoacoustic Emissions(DPOAEs) are thought to be generated from the cochlear outer hair cells. DPOAEs can be measured in the external ear canal twofold:amplitude and latency. However, most DPOAE studies deal with amplitude aspects. If DPOAE latency is related to the progression of the traveling wave along the basilar membrane, it may also reflect the cochlear function. The purpose of this study was to investigate if the latency measurement could be used as a clinical test of hearing. For this purpose, DPOAE latency measures were examined as a function of frequency from 1 to 8 kHz in 38 normal ears from 19 adults(7 females and 12 males). Results showed that the latency decreased as frequency increased up to 6 kHz. Test/retest reliability was relatively high in 4-6 kHz and the lowest at 1 kHz. There was no gender effect for all test frequencies. The results suggest that the measurement of DPOAE latency has a clinical potential, but more data be obtained before it can be clinically used.