Transient Evoked Otoacoustic Emissions Amplitude Research Articles

Hearing profile of recovered severe acute respiratory syndrome Coronavirus-2 (SARS-COV2) patients

BackgroundCoronaviruses are large, encapsulated RNA viruses that can infect both humans and animals and cause minor respiratory illnesses. In December 2019, numerous cases of pneumonia of unknown origin were reported in Wuhan, China. Coronavirus Disease 2019 (COVID-19), the cause of these cases, was discovered on January 6, 2020. The new coronavirus was declared an epidemic by the WHO on March, 2020. Several studies on COVID-19 have found that auditory complaints and hearing impairment can be detected using various tests.ObjectivesPure tone audiometry (PTA) and transient evoked otoacoustic emissions (TEOAEs) were used to assess hearing in recovered SARS-CoV-2 patients. Also, to compare the presence of patient's auditory complaints with the test findings.MethodsA case- control study was conducted, with each case and control group consisting of 58 people who were age and sex matched and ranged in age from 18 to 50 years. PTA, Extended PTA and, TEOAEs were used to evaluate hearing in both groups.ResultsPTA revealed a statistically significant difference in right ear thresholds at 250 Hz, 500 Hz, 4 kHz, and 8 kHz and left ear thresholds at 250 Hz, 4 kHz, 8 kHz, and 12.5 kHz between patients and controls. Additionally, a statistically significant difference in TEOAEs' overall reproducibility and amplitude between patients and controls was discovered. Affection for PTA and TEOAEs were related to the patient's complaints of hearing loss and tinnitus, respectively.ConclusionsWhether a patient is symptomatic or not, COVID-19 may have a negative impact on their hearing.

Otoacoustic emission measurements: a test–retest reliability study

ObjectivesOtoacoustic emissions (OAEs) are an important part of the audiological test battery and have many clinical uses. This study aims to determine the amplitude changes in the test–retest condition of distortion product otoacoustic emissions (DPOAEs) and transient-evoked otoacoustic emissions (TEOAEs), which are widely used in clinical settings.DesignDPOAE and TEOAE measurements were taken in 110 ears of 55 adults aged 18–35 years with normal hearing during three sessions. The repeatability of the measurements was evaluated by very short-term measurements taken 20 min after the first measurement and by short-term measurements taken 20 days after the first measurement.ResultsThere was no statistically significant difference between the three measurements in which DPOAE and TEOAE amplitudes were evaluated. The weakest reliability for TEOAEs was determined at frequencies of 1.0 kHz and 1.5 kHz, and the weakest reliability for DPOAEs was determined at 6728 Hz.ConclusionsThe current findings indicate that DPOAE and TEOAE measurements are reliable for monitoring cochlear function over time. The data obtained from this study could help clinicians correctly interpret OAE changes and distinguish between physiological and pathological changes.

Cochlear Function in Individuals with and without Spontaneous Otoacoustic Emissions.

This study investigated the status of spontaneous otoacoustic emissions (SOAEs) on cochlear function in a cohort of male/female participants with a wide age range. It examined whether there was a correlation between the presence of SOAEs and measurements of transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), SOAEs and extended high-frequency (EHF) hearing thresholds. 463 participants (222 male, 241 female; age range 20-59 years) with pure-tone thresholds ≤25 dB HL for octave frequencies of 500-8000 Hz were included in the study, divided into three age groups (20-29, 30-39, and 40-59 years). Evaluations included EHF (9000-16,000 Hz) hearing thresholds and TEOAE, DPOAE and SOAE measures. Multiple regression models showed that participants with SOAEs had larger expected amplitudes and signal-to-noise ratios (SNRs) for TEOAE and DPOAE responses than participants without SOAEs, holding gender and age variables constant. Spearman correlation tests identified deterioration in TEOAE and DPOAE amplitudes and SNRs, and EHF hearing thresholds with age in participants without SOAEs. Among participants with SOAEs, no significant decreases in TEOAE and DPOAE measures were shown in participants with older age. Nonetheless, as expected, EHF hearing thresholds did become worse with age, with or without SOAEs. Participants with identifiable SOAEs had greater TEOAE and DPOAE amplitudes and SNRs than participants without SOAEs. SOAEs appear to be a useful marker of cochlear health in adults.

The Magnitude of Contralateral Suppression of Otoacoustic Emissions Is Ear- and Age-Dependent

The maturation of the uncrossed medial olivocochlear (UMOC) efferent remains poorly documented to date. The UMOC efferent system allows listeners to not only detect but also to process, recognize, and discriminate auditory stimuli. Its fibers can be explored non-invasively by recording the effect of contralateral acoustic stimulation (CAS), resulting in a decrease in the amplitude of transient evoked otoacoustic emissions (TEOAE). The objective of the present cross-sectional study was to investigate how the effectiveness of this system varies with age in healthy subjects aged 8 years to adulthood. For this purpose, 120 right-handed native French-speaking subjects (57 females and 63 males) were divided into five age groups of 24 subjects each: 8y–10y, 10y–11y6m, 11y6m–13y, 13y–17y, and ≥18y. TEOAE amplitudes with and without CAS were recorded. The equivalent attenuation (EA) was calculated, corresponding to the change in TEOAE amplitude equivalent to the effect generated by CAS. General linear models were performed to control for the effect of ear, sex, and age on EA. No sex effect was found. A stronger EA was consistently found regardless of age group in the right ear compared to the left. In contrast to the right ear, for which, on average, EA remained constant across age groups, an increasingly weaker TEOAE suppression effect with age was found in the left ear, reinforcing the asymmetrical functioning of the UMOC efferent system in favor of the right ear in adulthood. Further studies are needed to investigate the lateralization of the UMOC efferent system and its changes over time in cases of atypical or reversed cortical asymmetries, especially in subjects with specific learning disorders.

ABO blood group and cochlear function: evidence from a large sample size study

Objective The present study investigated the effect of blood group on cochlear function in a large participant sample across different age groups. The study hypothesis was that participants with blood group O would show relatively reduced cochlear function as reflected in otoacoustic emission (OAE) measures. Design Data were collected from transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), DPOAE input/output (I/O) function, and spontaneous otoacoustic emission (SOAE) recordings. Study sample Four hundred and sixty-three normal hearing adults aged 20–59 years among the four ABO blood groups participated in the study. Results TEOAE and DPOAE amplitudes did not reveal significant differences for participants with blood group O compared with participants with non-O blood groups. No significant differences in I/O function categories were found among participants with different blood groups. SOAE prevalence was also not significantly different across blood groups. However, previously reported age and gender differences for OAE variables were confirmed. Conclusions Participants with blood group O were not found to have significantly reduced cochlear function, based on OAE measures. Results from the current study do not support the hypothesis that normal hearing individuals with different ABO blood groups differ in level of cochlear function.

Medial olivocochlear reflex reliability: The effects of averaging and presence of synchronized spontaneous otoacoustic emissions.

The medial olivocochlear reflex (MOCR), usually assessed by the inhibition of transiently evoked otoacoustic emissions (TEOAEs) with contralateral noise, is a very small effect. In understanding the origin of the MOCR, it is crucial to obtain data of the highest accuracy, i.e., with a high signal-to-noise ratio (SNR), which in turn largely depends on the number of signal averages. This study investigates how the reliability of MOCR measures is affected by the number of averages. At the same time, the effect of the presence of synchronized spontaneous otoacoustic emissions (SSOAEs) is taken into account, as it is known that this factor significantly affects TEOAE amplitudes and SNRs. Each recording session consisted of two series of four measurements, allowing comparison of MOCR magnitude based on 250, 500, 750, and 1000 averages. Reliability was based on comparing the two series. The results show that, for a good quality MOCR measure (i.e., intraclass correlation above 0.9), the required number of averages is at least double that obtainable from a standard TEOAE test (i.e., 500 compared to 250). Ears without SSOAEs needed a higher number of averages to reach a correlation of 0.9 than ears with SSOAEs.

Contralateral Suppression of Transient-evoked Otoacoustic Emissions in Leisure Noise Exposed Individuals.

Leisure noise may have a significant impact on hearing thresholds and young adults are often exposed to loud music during leisure activities. This behavior puts them at risk of developing noise-induced hearing loss (NIHL). A frequent initial indication of NIHL is reduced hearing acuity at 4 kHz. The objective of the current study was to assess the role of the medial olivocochlear reflex (MOCR) in leisure noise-exposed individuals with and without a 4-kHz notch. Audiological evaluation, including pure-tone and immittance audiometry, was performed for 156 college-going, young adults between May 2019 to December 2019. All participants had averaged pure-tone audiometric thresholds within normal limits, bilaterally. Annual individual exposure to personal listening devices (PLDs) was calculated using the Noise Exposure Questionnaire. The participants were then categorized into exposed (with and without audiometric 4 kHz notch) and nonexposed groups. Transient-evoked otoacoustic emission amplitude and its contralateral suppression were measured using linear and nonlinear click stimuli to study the effect of leisure noise exposure on MOCR. A significantly reduced overall contralateral suppression effect in participants exposed to PLD usage (P = 0.01) in both linear and nonlinear modes. On the contrary, significantly increased suppression was observed in linear mode for the 4 kHz frequency band in the PLD-exposed group without an audiometric notch (P = 0.009), possibly suggesting an early biomarker of NIHL. Measuring contralateral suppression of otoacoustic emissions may be an effective tool to detect early NIHL in leisure noise-exposed individuals.

Audiological findings in individuals diagnosed with COVID-19

PurposeIt is thought that COVID-19 may cause hearing loss, but its effects on the hearing system are not clear. This study aimed to reveal the effects of COVID-19 on the auditory system by using various audiological measurement methods in individuals diagnosed with COVID-19. MethodsThirty individuals between the ages of 18–45, who were diagnosed with COVID-19 by PCR at least one month ago, and had no pre-COVID-19 hearing loss complaints, constituted the test group. Thirty individuals aged between 18 and 30 years and who had no history of hearing loss constituted the control group. Audiological evaluations of all participants were made with pure-tone audiometry, high-frequency audiometry, transient-evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and auditory brainstem response (ABR) measurements. ResultsA significant difference was found between the groups at all high frequencies between 4 and 14 kHz (p < 0.05). TEOAE amplitudes at 1500 Hz, 2000 Hz and 4000 Hz frequencies and DPOAE amplitudes at 4003 Hz and higher frequencies were significantly lower in the test group (p < 0.05). While there was a significant difference between the I, III and V absolute latencies between the groups (p < 0.05), there was no significant difference between the I-III, III-V and I-V interpeak latencies (p > 0.05) as a result of the ABR test. ConclusionThis study showed that COVID-19 can cause cochlear damage, especially at high frequencies. More studies are needed to determine the effects of COVID-19 on the auditory system.

Lack of correlation between medial olivocochlear reflex strength and sentence recognition in noise

Objective The medial olivocochlear (MOC) reflex provides unmasking of sounds in noise, but its contribution to speech-in-noise perception remains unclear due to conflicting results. This study determined associations between MOC reflex strength and sentence recognition in noise in individuals with normal hearing. Design MOC reflex strength was assessed using contralateral inhibition of transient-evoked otoacoustic emissions (TEOAEs). Scores on the AzBio sentence task were quantified at three signal-to-noise ratios (SNRs). Additionally, slope and threshold of the psychometric function were computed. Associations between MOC reflex strength and speech-in-noise outcomes were assessed using Spearman rank correlations. Study sample Nineteen young adults with normal hearing participated, with data from 17 individuals (mean age = 21.8 years) included in the analysis. Results Contralateral noise significantly decreased the amplitude of TEOAEs. A range of contralateral inhibition values was exhibited across participants. Scores increased significantly with increasing SNR. Contrary to hypotheses, there were no significant correlations between MOC reflex strength and score, nor were there any significant correlations between MOC reflex strength and measures of the psychometric function. Conclusions Results found no significant monotonic relationship between MOC reflex strength and sentence recognition in noise. Future work is needed to determine the functional role of the MOC reflex.

Comparison of pure tone audiometry thresholds and transient evoked otoacoustic emissions (TEOAE) of patients with and without Covid-19 pneumonia

ObjectiveCOVID-19 is an infectious disease caused by the new coronavirus that starts similar to an upper respiratory tract infection and causes death by causing pneumonia and vasculopathy. Many viral infections are known to cause hearing loss. In this study, pure-tone audiometry (PTA) thresholds and Transient Evoked Otoacoustic Emissions (TEOAE) results were compared across patients with COVID-19 disease and COVID-19 pneumonia, and control group patients. MethodsThe study included 240 patients in the age range of 18–50 years. The patients were divided into three groups of 80 patients as the control (no disease), COVID-19 (nonpneumonia), Covid-19 (pneumonia) groups. PTA and TEOAE tests were performed on the control group patients and the results were recorded. PTA and TEOAE tests were performed in the COVID-19 groups in the first and third months after the infection ended. Each test was performed twice; the results were recorded, and the mean of the two results was calculated. ResultsPTA results and TEOAE amplitudes in the first and third months were not significantly different between the COVID-19 non-pneumonia group and the control group (p > 0.05), between the COVID-19 pneumonia group and the control group (p > 0.05), and between the COVID-19 non-pneumonia group and the COVID-19 pneumonia group (p > 0.05). ConclusionsDespite minimal impairment and minimal amplitude decreases in patients, who recovered from COVID-19, such changes were found to become restored in the third month. Furthermore, no significant changes were observed to indicate COVID-19- associated hearing loss.

Audiological involvement in patients with systemic sclerosis

The aim of the present study was to evaluate hearing loss in patients diagnosed with systemic sclerosis (SSc) and to investigate the relation between hearing loss, subtypes of the disease, its duration and clinical findings, and antibody positivity. The study included 47 patients with SSc and 44 healthy controls. Audiometric, tympanometric, and otoacoustic emission measurements were applied to both groups. The evaluation of the participants medical history showed that among the patients with SSc, 19.1% experienced ear fullness, 27.7% experienced vertigo, and 36.2% experienced tinnitus. Hearing loss was detected in 23.4% of the patients with SSc. The corresponding result was 4.3% in the control group with a statistically significant difference (p = 0.001). Transient-evoked otoacoustic emission amplitude values were significantly lower in the patients' both ears with SSc than the control group (p < 0.005). Duration of disease was significantly longer, and diffusing capacity of the lungs for carbon monoxide values were significantly higher in the patients with SSc and sensorineural hearing loss. The present study found that the incidence of hearing loss was significantly higher in the study group than in the healthy control group. In addition to other organ involvements, cochlear involvement occurs in these patients, and further studies are required.

Transient otoacoustic emissions and audiogram fine structure in the extended high-frequency region

Objective Previous studies at conventional audiometric frequencies found associations between the ripple depth seen in audiogram fine structure (AFS) and amplitudes of both transient evoked otoacoustic emissions (TEOAEs) and overall hearing threshold levels (HTLs). These associations are explained by the cochlear mechanical theory of multiple coherent reflections of the travelling wave apically by reflections sites on the basilar membrane and basally by the stapes. Design The aim was to investigate whether a similar relationship is seen in the extended high-frequency (EHF) range from 8–16 kHz. Measurements from 8–16 kHz were obtained in normal-hearing subjects comprising EHF HTLs, EHF TEOAEs using a double evoked paradigm, and Bekesy audiometry to assess AFS ripple depth and spectral periodicity. Study Sample Twenty eight normal-hearing subjects participated. Results Results showed no significant correlation between AFS ripple depth and either frequency-averaged EHF HTLs or EHF TEOAE amplitudes. The amplitude of AFS ripple depth was also lower than that seen in the conventional frequency region and spectral periodicity in the ripple more difficult to discern. Conclusion The results suggest a weaker interference pattern between forward and reverse cochlear travelling waves in the most basal region compared to more apical regions, or a difference in cochlear mechanical properties.

Otoacoustic emissions and contralateral suppression in tinnitus sufferers with normal hearing

BackgroundThe general consensus on the role of hearing loss in generating tinnitus is not relevant in tinnitus patients with normal hearing thresholds. One source of tinnitus may be related to damage to outer hair cells (OHC) of the cochlea. If the OHC of the human cochlea are to be involved in the generation of tinnitus, testing of Otoacoustic emissions (OAE) could provide a reliable means of recording OHC dysfunction. We investigated the role of OHC and cochlear efferent system in tinnitus development in normal hearing ears through studying of Distortion Product Otoacoustic Emissions (DPOAE) and Transient Evoked Otoacoustic Emissions (TEOAE) amplitudes, contralateral suppression amplitudes and suppression value in 15 normal hearing tinnitus patients and 15 control subjects.ResultsMean f2 DPOAE amplitudes and contralateral suppression were significantly lower in tinnitus group compared to controls for all frequencies from 1001 to 6348 Hz. Suppression values of DPOAEs revealed lower but not significant difference between tinnitus and control groups for all frequencies except 1587 and 6348 Hz. TEOAE amplitudes and contralateral suppression were significantly lower in tinnitus groups for all frequencies from 1000 to 4000 Hz compared to the control group. Suppression value of TEOAEs revealed no significant difference between the two groups for all frequencies except 3000 and 4000 Hz were significantly lower in the tinnitus group compared to the control group.ConclusionsNormal hearing manifested by pure tone audiometry in non-vascular tinnitus sufferers does not exclude OHC and/or cochlear efferent pathology.

Lack of association between contralateral inhibition of otoacoustic emissions and vowel formant discrimination in noise

Purpose The medial olivocochlear (MOC) reflex enhances neural encoding of signals in noise, and measurement of its function may hold clinical utility. Previous research on how the reflex aids speech-in-noise perception has been equivocal. Motivated by animal work, we examined associations between MOC reflex activity and formant discrimination in noise in humans to better understand how the MOC reflex contributes to audition. We hypothesised that participants with stronger MOC reflex activity would have better formant discrimination in noise abilities. Method Twenty-six normal-hearing listeners met all inclusion and exclusion criteria (mean age = 21.5 years), with data from 25 participants included in the final analysis. Transient-evoked otoacoustic emissions (TEOAEs) were measured in right ears. MOC reflex activity was assessed using a contralateral inhibition paradigm in which the change in TEOAE amplitude without versus with a contralateral MOC reflex elicitor was computed. Formant discrimination thresholds for a synthetic vowel /ɛ/ were obtained in right ears using a two-alternative forced-choice procedure that adaptively varied the second formant frequency. Discrimination thresholds were obtained at three signal-to-noise ratios (SNRs). Results TEOAE amplitudes were significantly reduced in the presence of the reflex elicitor (p < .05). Discrimination thresholds decreased significantly with increasing SNR (p < .05 in all cases). No significant correlations were found between contralateral inhibition measures and discrimination thresholds at any SNR (p > .05 in all cases). Conclusion Contrary to hypothesis, no significant associations were found between contralateral inhibition and formant discrimination in noise performance. It is possible that the MOC reflex contributes to formant discrimination but not in a monotonic fashion. Future work should consider investigating how the MOC reflex contributes to other perceptual properties to better characterise the functional relevance of the MOC reflex.

Post-exposure effect of music through personal listening device (PLD) on speech perception in noise test in young adults

Introduction: Tinnitus is often perceived temporarily after noise exposure, usually disappearing within a few hours. However, a significant number of young people perceive permanent tinnitus which is the most frequent symptom following exposure to noise via PLDs.Objective: To evaluate the effect of music exposure through (PLD) with and without tinnitus on results of EHFA, TEOAEs, ABR and SPIN tests in normal hearing young adults.Patients and Methods: Sixty normal hearing young adults were included in this study, fifteen as a control group and forty-five PLDs users as study group, the study group were subdivided according to the presence of tinnitus into two subgroups. All subjects were submitted to basic audiological evaluation (pure tone audiometry, speech audiometry and immittancemetry), Extended high frequency audiometry (EHFA), transient evoked otoacoustic emissions (TEOAEs), auditory brainstem response (ABR) and speech perception in noise (SPIN) test.Results: There were statistically significant differences in extended high frequency audiometry (HFA) at different frequencies among study and control groups. There were statistically significant differences in transient evoked otoacoustic emission test (TEOAEs) response among control and study groups. There were no statistically significant differences in absolute and inter-peak latencies of low and high repetition rate ABR among control and studied groups. There were statistically significant differences in speech perception in noise test (SPIN) among the control and study groups.Conclusion: : exposure to recreational noise due to excessive PLDs usage cause elevated EHFA thresholds, decreased TEOAEs amplitudes and decreased SPIN scores despite normal conventional PTA thresholds.

Short-Term Reliability of Different Methods of Contralateral Suppression of Transient Evoked Otoacoustic Emission in Children and Adults.

Purpose This study aimed to investigate the reliability of 3 methods to measure contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in children and adults. Method Contralateral suppression of TEOAEs was measured in 14 adults and 14 children using 3 methods with and without contralateral acoustic stimulus (CAS). Method-I having "2 s on-off" and Method-II having "10 s on-off" interleaved presentation of white noise. Method-III used "continuous presentation of white noise". Test-retest reliability was checked in adults without removing the probe (same-probe recording) and reinserting the probe (different-probe recording) and in children using a different-probe recording. Results The absolute suppression amplitude of TEOAEs was higher for "continuous noise," followed by "10 s on-off" and "2 s on-off" CAS. There was no significant effect of age across the 2 probe recordings, 3 methods of TEOAEs with and without CAS, and for the absolute suppression amplitude. Also, in adults, there was no significant difference between same-probe and different-probe recordings across the 3 methods. High internal consistency was observed on Cronbach's alpha (α > .9) for the 3 methods and 2 probe recordings. High agreement and correlation between the recordings for all 3 methods were seen using Bland-Altman plots and Pearson product-moment correlation coefficient. Conclusion The study demonstrated that highly reliable contralateral suppression of TEOAE can be measured using the 3 methods in adults and children. However, continuous presentation of CAS resulted in greater TEOAE suppression amplitude compared to interleaved presentation of CAS; hence, the former is recommended.

Effect of Negative Middle Ear Pressure and Compensated Pressure on Wideband Absorbance and Otoacoustic Emissions in Children.

Objective This study investigated pressurized transient evoked otoacoustic emission (TEOAE) responses and wideband absorbance (WBA) in healthy ears and ears with negative middle ear pressure (NMEP). Method In this cross-sectional study, TEOAE amplitude, signal-to-noise ratio, and WBA were measured at ambient and tympanometric peak pressure (TPP) in 36 ears from 25 subjects with healthy ears (age range: 3.1-13.0 years) and 88 ears from 76 patients with NMEP (age range: 2.0-13.1 years), divided into 3 groups based on NMEP (Group 1 with TPP between -101 and -200 daPa, Group 2 with TPP between -201 and -300 daPa, and Group 3 with TPP between -301 and -400 daPa). Results Mean TEOAE amplitude, signal-to-noise ratio, and WBA were increased at TPP relative to that measured at ambient pressure between 0.8 and 1.5 kHz. Further decrease in TPP beyond -300 daPa did not result in further increases in the mean TEOAE or WBA at TPP. The correlation between TEOAE and WBA was dependent on the frequency, pressure conditions, and subject group. There was no difference in pass rates between the 2 pressure conditions for the control group, while the 3 NMEP groups demonstrated an improvement in pass rates at TPP. With pressurization, the false alarm rate for TEOAE due to NMEP was reduced by 17.8% for NMEP Group 1, 29.2% for NMEP Group 2, and 15.8% for NMEP Group 3. Conclusion Results demonstrated the feasibility and clinical benefits of measuring TEOAE and WBA under pressurized conditions. Pressurized TEOAE and WBA should be used for assessment of ears with NMEP in hearing screening programs to reduce false alarm rates.

Study of cochlear function in neonates and infants with congenital hypothyroidism

ObjectiveTo investigate the signal amplitudes of transient evoked otoacoustic emissions (TEOAE) in neonates and infants diagnosed with congenital hypothyroidism (HC) and verify their association with clinical and laboratory aspects. MethodsA cross-sectional study with a convenience sample of 22 individuals with congenital hypothyroidism and a group of 22 individuals without the disease, neonates and infants, aged 0–12 months. The TEOAE amplitudes were evaluated in both groups and compared using the Mann-Whitney test. The existence of association between TEOAE amplitudes and clinical-laboratory variables was verified through the Spearman correlation coefficient. ResultsThere were no statistically significant differences between TEOAE amplitudes between the two groups. There was an association between the amplitudes of TEOAE and serum levels of thyroid stimulating hormone (TSH) and free thyroxine (T4) in the diagnostic test. ConclusionsThe existence of an association between serum levels of TSH and free T4 in the diagnostic test and the amplitudes of TEOAE suggests the influence of these hormones on the auditory function.

Are ABO Blood Groups or Rh Antigen Perinatal Factors Affecting the Pass Rate of Transient Otoacoustic Emissions Screening Tests in Healthy Newborns during the First 48 h of Life?

Most hospitals recommend performing neonatal hearing screening. Transient evoked otoacoustic emission (TEOAE) tests represent an ideal technique for conducting this process. Previous studies have related the influence of ABO blood group and Rhesus antigens (Rh) on the susceptibility to various pathologies. However, available data about the potential relationship between ABO blood groups, Rh, and TEOAE pass rates are sparse. Recently, several authors concluded that O blood group and Rh+ are possible influential factors of TEOAE pass rates. Significantly different TEOAE amplitude response between the four main ABO blood groups were observed among normal-hearing individuals. Moreover, ABO blood groups were discussed as a possible influential factor for the development of noise-induced hearing loss later in life. The aim of this study was to investigate the relationship between ABO blood groups, Rh, and the first TEOAE pass rates in healthy newborns. Data were retrospectively collected from healthy newborns at the maternity ward of F. Borja hospital in Gandia (Spain). Rh and ABO were compared with the results of TEOAE performed within the first 48 h of life. Results: the study group included 2765 newborns. No significant correlation between ABO blood group or Rh and TEOAE pass rates was observed in comparative tables. Conclusion: ABO blood group and Rhesus antigens do not appear to have a significant impact on the pass rate of TEOAE screening in healthy newborns.

Abnormalities of Otoacoustic Emissions in Myasthenia Gravis: Association With Serological and Electrophysiological Features.

Objective: To investigate whether otoacoustic emissions (OAEs) are impaired in patients with myasthenia gravis (MG) and whether such dysfunction is associated with serological and electrophysiological features of MG.Methods: We tested 15 patients with MG (30 ears) and 10 healthy age- and sex-matched subjects (20 ears) for transiently evoked OAE (TEOAE) and distortion product OAE (DPOAE).Results: Compared with controls, MG patients revealed a significant reduction in the amplitude of TEOAEs (p < 0.05) and DPOAEs at higher frequencies between 2,026 and 4,053 Hz (p < 0.05). In the subgroup analysis, TEOAE and DPOAE amplitudes were significantly lower in the acetylcholine receptor (AChR) antibody-positive group (p < 0.05) as well as in the repetitive nerve stimulation (RNS)-positive (p < 0.05) group. In particular, the OAE alteration significantly correlated with anti-AChR antibody titers. No significant difference of the OAEs was found between thymomatous and non-thymomatous MG or between purely ocular and generalized MG.Conclusions: Our study confirms that OAEs reveal subclinical dysfunction of the cholinergic neurotransmission of cochlear outer hair cells and correlate well with electrophysiological and serological characteristics of MG patients. Our findings imply that the measurement of OAEs might increase the diagnostic accuracy and help to monitor the severity of MG.