Search

Introduction: In recent years, research on the effect of blood group on hearing function has gained more attention. Some blood groups show susceptibility to certain general health and auditory disorders like noise induced hearing loss, infections, coronary artery disease, gastric carcinoma and duodenal ulcer. Aims: The present study aimed to determine the differences in middle ear and cochlear function among persons with different blood groups (AB, A, B, O). Materials and methods: Sixty adults (18–24 years) with normal hearing sensitivity were included in the study. They were divided into four groups based on blood groups (A, B, AB, O) with 15 participants each. High-frequency thresholds, distortion product otoacoustic emissions (DPOAE) and resonance frequency were measured. High-frequency thresholds for both ears were measured at octave frequencies from 9 kHz to 16 kHz. Resonant frequency was determined using sweep frequency method. Results: The findings demonstrated that individuals with blood group AB and O had considerably lower DPOAE amplitudes. Resonance frequency and extended high frequency thresholds did not, however, differ significantly between the blood groups. Conclusion: The decrease in the amplitude of otoacoustic emissions (OAE) can be explained by a reduction in the quantity of robust outer hair cells and elevated protein levels, which in turn lead to a reduction in the cochlear blood flow in persons with blood type O and AB, respectively. More research with greater numbers of participants is necessary to improve the generalization of the findings. [ABSTRACT FROM AUTHOR]

Introduction: Some electrophysiological changes can occur in the auditory system in response to noise exposure with or without any permanent auditory threshold shift. The purpose of this study was to identify and measure cochlear function after noise exposure in individuals with normal hearing according to standard audiometric thresholds. Material and methods: Pure tone audiometry (PTA) over the standard 0.250--8 kHz range and at 12 kHz, as well as distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) testing, were performed on 42 soldiers who had participated in combat. A control group of 40 participants underwent the same tests. Results: In the noise-exposed group, significantly poorer PTA thresholds were recorded at 12 kHz. DPOAE levels were significantly low only at 4 kHz. On ABR testing, both wave I and wave V demonstrated a significant decrease in amplitude and a significant increase in latency for the noise-exposed group. Conclusions: Our findings reveal that high levels of noise can not only damage outer hair cells but also cause changes at the level of the synapses (synaptopathy) which are not evident using standard PTA tests. However, electrophysiological methods can detect some changes in cochlear function. [ABSTRACT FROM AUTHOR]

Background: Cellular stress caused by noise-induced hearing loss can be observed through the damage of cochlear hair cells, mechanically and metabolically. SNR value on the DPOAE examination assesses the sensory function of cochlear outer hair cells. HSP70 as marker of cellular stress can be identified from its levels in blood and its expression in the cochlea. Methods: Three groups of rats were used for the noise intervention: Group 1 was the control group, Group 2 had a noise exposure of 100 dB, and Group 3 received a noise exposure of 110 dB. DPOAE examination was then conducted, blood samples from rats' tail were collected after a noise treatment, followed by the measurement of HSP70 levels by ELISA readings. Rats were terminated afterwards and immunohistochemical examination of the cochlear organ of Corti was performed to calculate the expression of HSP70. The data obtained were analyzed using SPSS. Results: A decrease occurred in the values of SNR and an increase occurred in HSP70 levels in blood along with its expression in the cochlea of noise model Rattus norvegicus, and there is a correlation between the three. Conclusion: The decrease in SNR values, increase in HSP70 levels in blood, and increase in HSP70 expression in the cochlear organ of Corti of Rattus norvegicus, proves that noise-induced hearing loss triggers the production of HSP70 as a cytoprotective agent in preventing inner ear damage. [ABSTRACT FROM AUTHOR]

Introduction: Gestational diabetes is a potential risk factor for neonatal hearing loss. Increased circulating sugars in mothers during pregnancy can impairs the micro circulation and can cause congenital anomalies of the inner ear resulting in congenital hearing loss. This study attempts to find the incidence of neonatal hearing loss among diabetic mothers. Methodology: This was a case control study with 86 neonates of diabetic mothers as cases and neonates of non diabetic mothers(n = 86) as controls. Antenatal diabetic history and sugar values of mothers were documented. Hearing status of the neonates were tested using DPOAE test and ABR test. DPOAE test was done on 3rd day and those who did not get a positive response underwent 2nd DPOAE and also ABR test if 2nd DPOAE was negative. Results: All neonates underwent DPOAE test and few were lost on follow up. First and second DPOAE showed a statistically significant difference between cases and controls. All babies who underwent ABR test had abnormal waveforms. 98% of cases showed moderate and severe bilateral hearing loss whereas all controls had only mild bilateral hearing loss. Discussion: This study showed a significantly higher percentage of abnormal hearing outcome among neonates of diabetic mothers than non diabetic mothers. This could be because of the toxic effects of maternal hyperglycemia on developing auditory system of the fetus. This study emphasis the need for better glycaemic control in diabetic pregnancy, the importance of early and mandatory hearing screening in newborns of diabetic mothers. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Age‐related hearing loss is an important risk factor for cognitive decline. However, audiogram thresholds are not good estimators of dementia risk in subjects with normal hearing or mild hearing loss. Here we propose to use distortion product otoacoustic emissions (DPOAEs) as an objective and sensitive tool to estimate the risk of cognitive decline in older adults with normal hearing or mild hearing loss. METHODS: We assessed neuropsychological, brain magnetic resonance imaging, and auditory analyses on 94 subjects > 64 years of age. RESULTS: We found that cochlear dysfunction, measured by DPOAEs—and not by conventional audiometry—was associated with Clinical Dementia Rating Sum of Boxes (CDR‐SoB) classification and brain atrophy in the group with mild hearing loss (25 to 40 dB) and normal hearing (<25 dB). DISCUSSION: Our findings suggest that DPOAEs may be a non‐invasive tool for detecting neurodegeneration and cognitive decline in the older adults, potentially allowing for early intervention. [ABSTRACT FROM AUTHOR]

Abstract Objectives Otoacoustic 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. Design DPOAE 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. Results There 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. Conclusions The 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.

Abstract INTRODUCTION Age‐related hearing loss is an important risk factor for cognitive decline. However, audiogram thresholds are not good estimators of dementia risk in subjects with normal hearing or mild hearing loss. Here we propose to use distortion product otoacoustic emissions (DPOAEs) as an objective and sensitive tool to estimate the risk of cognitive decline in older adults with normal hearing or mild hearing loss. METHODS We assessed neuropsychological, brain magnetic resonance imaging, and auditory analyses on 94 subjects > 64 years of age. RESULTS We found that cochlear dysfunction, measured by DPOAEs—and not by conventional audiometry—was associated with Clinical Dementia Rating Sum of Boxes (CDR‐SoB) classification and brain atrophy in the group with mild hearing loss (25 to 40 dB) and normal hearing (

Military Working Dogs (MWD) are placed in high levels of noise inside and outside their work activities. These hazardous noise levels have the potential to have adverse effects on the dog's auditory system. This study aimed to measure the typical kennel noise levels over a 24-hour period and conduct audiological testing on the MWDs. Most audiological testing is normed on humans but there is a need for canine norms. This study used four different distortion product otoacoustic emissions (DPOAE) protocols on 36 MWDs. The protocols varied in L1 /L2 intensity levels at L1=65dB, L2=65dB (DP65/65), L1=65dB, L2=55dB (DP65/55), L1=55dB, L2=55dB (DP55/55), and L1=55dB, L2=45dB (DP55/45). Descriptive statistics and one-way ANOVAs were used for analysis. Kennel noise exceeded the DoD hearing conservation program action level of 85 decibels A-weighting for humans. DPOAE testing showed that the largest amplitude responses came from the DP65/55 protocols. This is seen similarly in human DPOAE testing. DP65/55 reports a twofold advantage of producing higher DPOAE amplitudes with an improved sensitivity to cochlear mechanics. Optimal testing parameters allows veterinarians and audiologists to understanding the status of an MWD's auditory system and support in providing feedback regarding hearing abilities or hearing loss. [ABSTRACT FROM AUTHOR]

Objectives: Otoacoustic 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. Design: DPOAE 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. Results: There 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. Conclusions: The 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. [ABSTRACT FROM AUTHOR]

Hearing is normally evaluated up to 8 kHz, even though testing can easily be performed at higher frequencies (up to 16 or 20 kHz). The range beyond 8 kHz is often referred to as the extended high frequency (EHF) range. This study aimed to explore the relationship between EHF hearing thresholds (HTs) and distortion product otoacoustic emissions (DPOAEs) in adult subjects. Also of interest were the effects of the presence of spontaneous otoacoustic emissions (SOAEs), gender, ear side, and age. The main finding was that DPOAEs, both within the standard frequency (SF) range (0.125–8 kHz) and the EHF range (10–16 kHz), decrease as thresholds deteriorate. For both ranges, DPOAEs and HTs depend on age, even for those with normal hearing, although EHFs seem to be especially affected by age. The presence of SOAEs was the only other factor that significantly influenced DPOAE level. For both DPOAEs and HTs, only minor and non-significant effects were related to gender and ear side. It was concluded that DPOAEs in the EHF range appear to be good predictors of EHF HTs. Moreover, since DPOAEs and HTs in the EHF range both correlate with age, these two measures may be suitable markers for incipient presbycusis. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether preeclampsia and gestational diabetes mellitus is a risk factor for cochlear damage and sensorineural hearing impairment in infants. Materials and Methods: Longitudinal study was conducted in 2 tertiary referral centers. 1068 neonates were included, who were born to preeclampsia, gestational diabetes mellitus, and healthy mothers. The hearing evaluation was done using DPOAE on day 2 and for those who failed the initial DPOAE on day 2, underwent repeat DPOAE on day 15, ABR was done on day 30 if repeat DPOAE was Refer. The results were compared between the groups and analyzed. Results: On initial DPOAE, bilateral ear absent DPOAE rates were 19.5%, 15.8%, and 3.5% among preeclampsia, Gestational Diabetes Mellitus (GDM), control groups respectively. The difference was statistically significant (P <.001). Also it was noted that absent DPOAE was significantly high at low and mid frequencies (1000, 2000, 3000, and 4000 Hz) in bilateral ear. However the difference in repeat DPOAE among the groups were not significant (Right ear P =.17, Left ear P =.31). Infants who failed repeat DPOAE test underwent ABR test in which 3 of GDM group, 2 infants of preeclampsia group and 1 infant of control group had absent ABR test. Conclusion: This study reveals that GDM and preeclampsia showed remarkable association of hearing loss at lower and mid frequencies which was transient. The prevalence of absent DPOAE was corresponding to the severity of the maternal conditions under the study. [ABSTRACT FROM AUTHOR]

Objective: In this study, we created an animal model to demonstrate the effects of thiamine on the hearing pathways of new-borns during pregnancy and lactation by inducing a dietary thiamine deficiency in the mother. Methods: The study included 16 female Wistar albino rats. The animals were separated into four groups and provided the appropriate amounts of dietary thiamine according to their groups during pre-pregnancy, pregnancy, and lactation periods. Three pups from each mother were included in the study, and 12 pups were selected from each group. On the fortieth day after birth, the auditory pathways of 48 pups in the 4 groups were examined electro physiologically and ultra-structurally. Results: In Group N-N, morphology of hair cells stereocilia degeneration was not obtained in all turns of cochlea. In Group N-T, Inner Hair Cells (IHCs) and Outher Hair Cells (OHCs) stereocilia didn’t show degeneration in all turns of cochlea but had rupture inrows of HCs stereocilia. In group T-N IHCs stereocilia less degeneration was observed in all turns of cochlea. OHC stereocilia partial loss was observed only in basal turn of cochlea. In Group T-T IHCs stereocilia was observed less degeneration and rupture in all turns of cochlea. Conclusion: Thiamine is vital for the development of cochlear hair cells during both prenatal and postnatal periods. Even partial deficiency of thiamine causes significant degeneration to the auditory pathway. Level of evidence: The level of evidence of this article is 5. This article is an experimental animal and laboratory study.

Hearing loss induced by noise and combinations of factors is a common occupational disease among workers. This study aimed to investigate the impact of acute exposure to white noise and Al2O3 NPs, alone and in combination, on changes in the hearing and structural functions of the cochlea in rats. Thirty-six rats were randomly assigned to one of six groups: Control, acute exposure to white noise, exposure to γ-Al2O3 NPs, exposure to noise plus γ-Al2O3 NPs, exposure to α-Al2O3 NPs, and exposure to the combination of noise plus α-Al2O3 NPs. TTS and PTS were examined using DPOAE, while oxidative index (MDA, GSH-Px), gene expression (NOX3, TGF-ß, CYP1A1), protein expression (ß-Tubulin, Myosin VII), and histopathological changes were examined in the cochlea. The morphology of Al2O3 NPs was examined by TEM. The results of the DPOAE test showed a significant increase in TTS in all groups and an increase in PTS in the groups exposed to noise, γ-Al2O3 NPs, and a combination of noise plus Al2O3 NPs (P < 0.05). In the group exposed to white noise plus Al2O3 NPs, the MDA levels increased, the level of GSH-Px decreased, and the expression percentage of ß-Tubulin and Myosin VII decreased, while the expression of NOX3, TGF-ß, and CYP1A1 (except for the α-Al2O3 NPs group) significantly increased (P < 0.05). Histopathological changes of the cochlea indicated damage to hair and ganglion cells, which was more severe in the combined exposure group. The combined and independent exposure to white noise and Al2O3 NPs damaged hair and ganglion cells for high-frequency perception, affecting the function and structure of the cochlea and leading to TTS and PTS. [ABSTRACT FROM AUTHOR]

The goal of this study is to compare three of the most commonly used primary-level relation paradigms (i.e., Scissors, Boys Town ‘Optimal’, and Equal-Level) in generation of distortion product otoacoustic emissions (DPOAEs) in normal hearing adults. The generator and reflection components were extracted from DPOAEs in each paradigm. The generator and reflection component levels and input/output (I/O) functions were compared across paradigms and primary-tone levels. The results showed a different I/O function growth behavior across frequency and levels among paradigms. The Optimal paradigm showed a systematic change in the generator and reflection component levels and I/O slopes across primary levels among subjects. Moreover, the levels and slopes in the Optimal paradigm were more distinct across levels with less variations across frequency leading to a systematic change in the DPOAE fine structure across levels. The I/O functions were found to be more sensitive to the selected paradigm; especially the I/O function for the reflection component. The I/O functions of the reflection components showed large variability across frequencies due to different frequency shifts in their microstructure depending on the paradigm. The findings of this study suggested the Optimal paradigm as the proper primary-level relation to study cochlear amplification/compression. The findings of this study shows that care needs to be taken in comparing the findings of different studies that generated DPOAEs with a different level-relation paradigm.

The goal of this study is to compare three of the most commonly used primary-level relation paradigms (i.e., Scissors, Boys Town 'Optimal', and Equal-Level) in generation of distortion product otoacoustic emissions (DPOAEs) in normal hearing adults. The generator and reflection components were extracted from DPOAEs in each paradigm. The generator and reflection component levels and input/output (I/O) functions were compared across paradigms and primary-tone levels. The results showed a different I/O function growth behavior across frequency and levels among paradigms. The Optimal paradigm showed a systematic change in the generator and reflection component levels and I/O slopes across primary levels among subjects. Moreover, the levels and slopes in the Optimal paradigm were more distinct across levels with less variations across frequency leading to a systematic change in the DPOAE fine structure across levels. The I/O functions were found to be more sensitive to the selected paradigm; especially the I/O function for the reflection component. The I/O functions of the reflection components showed large variability across frequencies due to different frequency shifts in their microstructure depending on the paradigm. The findings of this study suggested the Optimal paradigm as the proper primary-level relation to study cochlear amplification/compression. The findings of this study shows that care needs to be taken in comparing the findings of different studies that generated DPOAEs with a different level-relation paradigm. [ABSTRACT FROM AUTHOR]

Purpose: To explore the effect of inflammatory factors on inner ear impairment in a sample of Omicron-infected patients with a high rate of vaccination in China. Methods: One hundred and forty-six recovered Omicron-infected patients performed the distortion product otoacoustic emission (DPOAE) test and serum test for inflammatory factors; demographic data and vaccination statuses were collected from the questionnaire. Results: Out of 146 patients, the DPOAE pass rate was 81.5% (119/146). Inner ear impairment was significantly correlated with IL-6 titer. The odds ratio (aOR) was 1.24 (95% CI: 1.04–1.49) after adjusting for age, sex, and vaccine characteristics. Notably, this relationship only existed in the 18–60 years group. There were no significant protective effects of vaccination on inner ear function. Conclusions: Inner ear impairment still exists in Omicron-infected patients, which was significantly correlated with IL-6 titer. This relationship was mainly observed in young and middle-aged people, possibly due to a stronger immune response in this age group. The protective effect of vaccination on the inner ear could not be proved. [ABSTRACT FROM AUTHOR]

While most anuran species are highly vocal, few of them seem to be endowed with a complex call repertoire. Odorrana tormota, combines a remarkable vocalization complexity with auditory sensitivity over an extended spectral range spanning from audible to ultrasonic frequencies. This species is also exceptional for its ability to modify its middle ear tuning by closing the Eustachian tubes (ET). Using scanning laser Doppler vibrometry, the tympanal vibrations were measured to investigate if the tuning shift caused by the ET closure contributes to intraspecific acoustic communication. To gain insight into the inner ear frequency selectivity and sensitivity of this species, distortion product otoacoustic emissions were recorded at multiple frequency-level combinations. Our measurements of inner ear responses indicated that in O. tormota each sex is more sensitive to the frequencies of the other sex's vocalizations, female ears are more sensitive to 2–7 kHz, while male ears are more sensitive to 3–15 kHz. We also found that in both sexes the ET closure impacts the sensitivity of the middle and inner ear at frequencies used for communication with conspecifics. This study broadens our understanding of peripheral auditory mechanisms contributing to intraspecific acoustic communication in anurans. [ABSTRACT FROM AUTHOR]

Background New generation Doppler ultrasonography (DUSG) application effects on cochlea and cochlear nucleus (CN) are unclear. We aimed to investigate the effects of new generation DUSG application at different frequencies in prenatal period on cochlea and CN in rats. Objective Twenty-four pregnant female rats were divided into three groups (n = 8). Group 1 was the control group and was not subjected to any treatment. Group 2 was determined as the USG every day (USGED) treatment group. Group 2 has received DUSG application every day from the 4th to 18th day (20 min/15 per day). Group 3 has received DUSG application as “2 days/one dose as every other day application” (USG2D1) from the 4th to 18th day (20 min/8 every other day). Twenty-four female rats were sacrificed in 21 days. Also, 24 pups were sacrificed after two days. First day after born, the cochlear activities of the right ears of all pups were examined using DPOAEs. Second day, neural tissues from CN were evaluated histopathologically and immunohistochemically. Results There was no any statistical difference between the groups in respect of histopathologically. USGED group showed mild caspase-3 positive neurons and glial cells. However, there was no significant difference between the USGED and other groups (p>.05). Similarly, the rats applied with USG2D1 had mild caspase-3 expression, but no significant difference between the USG2D1 and other groups (p>.05). Differences in DPOAE amplitudes, and therefore in cochlear activity, between the groups were revealed. The decrease in cochlear activity between the groups involved frequencies at 2, 8, 16, and 32 kHz (p<.05). Conclusions Multiple administration of new generation DUSG to pregnant rats has not shown harmful effects on the cochlear neural tissue. High frequencies are more sensitive in cochlea to apply DUSG. [ABSTRACT FROM AUTHOR]

Hearing is normally evaluated up to 8 kHz, even though testing can easily be performed at higher frequencies (up to 16 or 20 kHz). The range beyond 8 kHz is often referred to as the extended high frequency (EHF) range. This study aimed to explore the relationship between EHF hearing thresholds (HTs) and distortion product otoacoustic emissions (DPOAEs) in adult subjects. Also of interest were the effects of the presence of spontaneous otoacoustic emissions (SOAEs), gender, ear side, and age. The main finding was that DPOAEs, both within the standard frequency (SF) range (0.125–8 kHz) and the EHF range (10–16 kHz), decrease as thresholds deteriorate. For both ranges, DPOAEs and HTs depend on age, even for those with normal hearing, although EHFs seem to be especially affected by age. The presence of SOAEs was the only other factor that significantly influenced DPOAE level. For both DPOAEs and HTs, only minor and non-significant effects were related to gender and ear side. It was concluded that DPOAEs in the EHF range appear to be good predictors of EHF HTs. Moreover, since DPOAEs and HTs in the EHF range both correlate with age, these two measures may be suitable markers for incipient presbycusis.

Allergic rhinitis is a type-I hypersensitivity reaction of the nasal mucosa, primarily mediated by immunoglobulin E (IgE) with complex etiological factors.Allergic rhinitis may involve the inner ear. The scientific basis for this is poorly understood. However, the inner ear has been found to demonstrate both cellular and humoral immunity, and the seat of immuno-activity appears to reside in the endolymphatic sac and duct. To assess the audiological profile of patients with allergic rhinitis. 100 Study group patients and 50 control group subjects underwent detailed audiological assessment. Present study revealed high frequency sensorineural hearing loss with prolongation of Wave I and shortened wave I–III and Wave I–V interpeak latencies on ABR and abnormal DPOAE findings, compared with controls which indicate inner ear involvement (cochlear pathology). Individuals with allergic rhinitis are more prone to hearing abnormalities which can be detected even before any symptoms of hearing impairment are present. However, the exact pathophysiology of inner ear damage in patients of airway allergy is poorly understood and therefore, additional studies in this area are required with a larger sample population to assess the benefits of hearing assessment in patients of allergic rhinitis for early detection of hearing loss. [ABSTRACT FROM AUTHOR]

Otoacoustic emissions (OAEs) arise from one (or a combination) of two basic generation mechanisms in the cochlea: nonlinear distortion and linear reflection. As a result of having distinct generation processes, these two classes of emissions may provide non-redundant information about hair-cell integrity and show distinct sensitivities to cochlear pathology. Here, we characterize the relationship between reflection and distortion emissions in normal hearers across a broad frequency and stimulus-level space using novel analysis techniques. Furthermore, we illustrate the promise of this approach in a small group of individuals with mild-moderate hearing loss. A "joint-OAE profile" was created by measuring interleaved swept-tone stimulus-frequency OAEs (SFOAEs) and 2f1-f2 distortion-product OAEs (DPOAEs) in the same ears using well-considered parameters. OAE spectra and input/output functions were calculated across five octaves. Using our specific recording protocol and analysis scheme, SFOAEs in normal hearers had higher levels than did DPOAEs, with the most pronounced differences occurring at the highest stimulus levels. Also, SFOAE compression occurred at higher stimulus levels (than did DPOAE compression) and its growth in the compressed region was steeper. The diagnostic implications of these findings and the influence of the measurement protocol on both OAEs (and on their relationship) are discussed. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate Auditory Evoked Brainstem Responses (ABR) and Distortion Product Otoacoustic Emission (DPOAE) suppression in migraine patients with and without phonophobia., Methods: Thirty-two migraine patients with normal hearing and 30 healthy individuals were included in the study. Migraine characteristics and phonophobia status of migraine patients were noted. The patients were divided into two groups according to their phonophobia status. All participants underwent ABR, DPOAE and DPOAE suppression., Results: Migraine patients had less DPOAE suppression (1481 and 2222 hz) and shorter ABR wave latencies compared to the control group ( p  < 0.05). Twelve (37.5%) of the migraine patients did not have phonophobia, and 20 (62.5%) had phonophobia. Phonophobia was not found to affect DPOAE suppression ( p  > 0.05). However, ABR wave I and V latencies in migraine patients with phonophobia were shorter than in healthy individuals ( p  < 0.05)., Conclusion: There are changes in the auditory evoked brainstem responses and medial olivocochlear efferent system of migraine patients. While phonophobia in migraine patients does not affect the medial olivocochlear efferent system, it may affect auditory evoked brainstem responses.

Introduction: Both auditory brainstem response audiometry (ABR) and otoacoustic emission (OAE) are two widely used tests for a neonatal hearing screening. The OAE is easier to perform, faster, and cost-effective. However, ABR is precise with few false-positive results. We intended to know the sensitivity and specificity of OAE compared to ABR. Methods: This cross-sectional study was conducted on 282 neonates in a neonatal intensive care unit (NICU) at Dhaka. All the neonates had one or more risk factors for hearing impairment (as defined by The Joint Committee of Infant Hearing). All the study subjects were screened by an expert team with a proper environment and machine (GSI AUDIOscreener, Denmark). Initial DPOAE was done within 30 days of age and then ABR, at three months. The results were expressed as “Pass” (probably no hearing impairment) or “Refer” (further evaluation is needed). Results: Among the 282 neonates, 44(15.6%) neonates were referred at the initial screening. However, at ABR it was found that 27 (9.5%) had a hearing impairment. Among these 27, twenty-four were also referred at DPOAE (true positive). But 3 were not detected by DPOAE (false-negative). Other 20 neonates who were referred at DPOAE, were normal at ABR (false-positive). So it was estimated that the sensitivity of DPOAE for identifying hearing loss was 88.9% and the specificity was 92.2%. Conclusion: The DPOAE is a good screening test for neonatal hearing screening with high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

In this study, our purpose is to evaluate cochlear and vestibular function in juveniles with IgA vasculitis using audiometry, distortion product otoacoustic emissions, and cervical vestibular evoked myogenic potential (cVEMP) tests. Forty children diagnosed with IgA vasculitis from the pediatry clinic and 40 age- and sex-matched healthy children were evaluated with distortion product otoacoustic emissions, audiometry, and cVEMP test in a tertiary hospital. The audiometry average values for both ears of the IgA vasculitis group and the control subjects were compared, and as a result, median 4.7-dB sensorineural hearing loss (SHL) was found for the IgA vasculitis group compared to the control group at 250 Hz and it was statistically significant (p < 0.001). An average of 6.4-dB SHL was detected at 8000 Hz (p < 0.001). There was a statistically significant difference among IgA vasculitis and control groups regarding measurement results of average p1-n1 latency time of both ears (0.9 ms (ms) increase, p = 0.035). In IgA vasculitis patients, the median amplitude difference of both ears' average p1 n1 was found to be 5.6 mV, statistically significantly decreased compared to the control group (p = 0.003).Conclusion: This study, firstly in literature, demonstrated that IgA vasculitis may have association with hearing loss and vestibular dysfunction in children. We think this might be due to autoimmune mechanisms.What Is Known: • Ig A vasculitis is a leukocytoclastic vasculitis with unknown etiology, involving the skin, joints, gastrointestinal system, kidneys, and rarely other organs. • No study has been reported for the cochlear and vestibular association of Ig A vasculitis in current literature.What Is New: • This study demonstrated that Ig A vasculitis may have association with hearing loss in children. • This study also demonstrated that Ig A vasculitis may have association with vestibular dysfunction in children. [ABSTRACT FROM AUTHOR]

Background: Hearing loss due to impaired cochlear function, which results from increased blood urea nitrogen (BUN) level, is one of the important clinical problems in chronic kidney disease (CKD) patients with uremia. This study aims to determine correlation between blood urea nitrogen (BUN) levels and cochlear Outer Hair Cell (OHC) dysfunction in non-dialysis stage 3-5 CKD patients so that the BUN levels may also be used to determine the presence of cochlear OHC dysfunction. Design and methods: An observational analytic study with a cross sectional design and consecutive sampling. This study was conducted from November 2019 to February 2020 at the Department of Internal Medicine, Soetomo Hospital, Surabaya, Indonesia, and Otorhinolaryngology-Head and Neck Surgery Department, Soetomo Hospital, Surabaya, Indonesia. Non-dialysis CKD patients who met the inclusion and exclusion criteria were subjected to a Distortion Product Otoacoustic Emissions (DPOAE) test to assess cochlear OHC function at the Otorhinolaryngology-Head and Neck Surgery, Soetomo Hospital, Surabaya. Results: Female patients were in larger number than male patients in a ratio of 1 : 2. Most of the patients were between 51-60 years of age. DPOAE distribution was referred in 25 patients (83.3%) and pass in 5 patients (16.7%). The highest pass was at 2000 Hz in 24 patients (80.0%), while the refer results were mostly at 12,000 Hz in 29 patients (96.7%). The highest average signal to noise ratio (SNR) was at 2000 Hz and 4000 Hz (12.77 dB and 11.13 dB), while the lowest at 11,000 Hz and 12,000 Hz (1.60 dB and 1.03 dB). Pearson's correlation test on DPOAE results did not show a significant correlation (P >0.05) between BUN levels and impaired cochlear OHC function. Conclusions: There was no correlation between increased blood urea nitrogen levels and cochlear outer hair cell function disorders in non-dialysis patients with CKD stage 3-5.

Stimulation of cholinergic efferent neurons innervating the inner ear has profound, well-characterized effects on vestibular and auditory physiology, after activating distinct ACh receptors (AChRs) on afferents and hair cells in peripheral endorgans. Efferent-mediated fast and slow excitation of vestibular afferents are mediated by α4β2*-containing nicotinic AChRs (nAChRs) and muscarinic AChRs (mAChRs), respectively. On the auditory side, efferent-mediated suppression of distortion product otoacoustic emissions (DPOAEs) is mediated by α9α10nAChRs. Previous characterization of these synaptic mechanisms utilized cholinergic drugs, that when systemically administered, also reach the CNS, which may limit their utility in probing efferent function without also considering central effects. Use of peripherally-acting cholinergic drugs with local application strategies may be useful, but this approach has remained relatively unexplored. Using multiple administration routes, we performed a combination of vestibular afferent and DPOAE recordings during efferent stimulation in mouse and turtle to determine whether charged mAChR or α9α10nAChR antagonists, with little CNS entry, can still engage efferent synaptic targets in the inner ear. The charged mAChR antagonists glycopyrrolate and methscopolamine blocked efferent-mediated slow excitation of mouse vestibular afferents following intraperitoneal, middle ear, or direct perilymphatic administration. Both mAChR antagonists were effective when delivered to the middle ear, contralateral to the side of afferent recordings, suggesting they gain vascular access after first entering the perilymphatic compartment. In contrast, charged α9α10nAChR antagonists blocked efferent-mediated suppression of DPOAEs only upon direct perilymphatic application, but failed to reach efferent synapses when systemically administered. These data show that efferent mechanisms are viable targets for further characterizing drug access in the inner ear. [ABSTRACT FROM AUTHOR]

Stimulation of cholinergic efferent neurons innervating the inner ear has profound, well-characterized effects on vestibular and auditory physiology, after activating distinct ACh receptors (AChRs) on afferents and hair cells in peripheral endorgans. Efferent-mediated fast and slow excitation of vestibular afferents are mediated by α4β2*-containing nicotinic AChRs (nAChRs) and muscarinic AChRs (mAChRs), respectively. On the auditory side, efferent-mediated suppression of distortion product otoacoustic emissions (DPOAEs) is mediated by α9α10nAChRs. Previous characterization of these synaptic mechanisms utilized cholinergic drugs, that when systemically administered, also reach the CNS, which may limit their utility in probing efferent function without also considering central effects. Use of peripherally-acting cholinergic drugs with local application strategies may be useful, but this approach has remained relatively unexplored. Using multiple administration routes, we performed a combination of vestibular afferent and DPOAE recordings during efferent stimulation in mouse and turtle to determine whether charged mAChR or α9α10nAChR antagonists, with little CNS entry, can still engage efferent synaptic targets in the inner ear. The charged mAChR antagonists glycopyrrolate and methscopolamine blocked efferent-mediated slow excitation of mouse vestibular afferents following intraperitoneal, middle ear, or direct perilymphatic administration. Both mAChR antagonists were effective when delivered to the middle ear, contralateral to the side of afferent recordings, suggesting they gain vascular access after first entering the perilymphatic compartment. In contrast, charged α9α10nAChR antagonists blocked efferent-mediated suppression of DPOAEs only upon direct perilymphatic application, but failed to reach efferent synapses when systemically administered. These data show that efferent mechanisms are viable targets for further characterizing drug access in the inner ear.

The presence of endolymphatic hydrops has been studied in many neurological disorders. The pathophysiological mechanisms may involve CSF pressure variations, transmitted to the innear ear. This hydrops could play a role in vestibular or cochlear symptoms. For the ENT specialist, the etiological diagnosis of endolymphatic hydrops is a challenge, and neurological etiologies must be known. The treatment of these neurological causes could be effective on cochleo-vestibular symptoms. The knowledge of endolymphatic hydrops could also be a target for noninvasive tests, able to estimate CSF pressure variations. For the neurologist, this could represent a useful tool for the diagnosis and follow-up, in some of these neurological disorders, related to a CSF pressure imbalance. The purpose of this paper is to summarize literature data on endolymphatic hydrops in neurological disorders. We define some neurological conditions, for which there is a particular interest in noninvasive investigations of endolymphatic hydrops. [ABSTRACT FROM AUTHOR]

ObjectiveTo describe and study the population statistics, hearing phenotype, and pathological changes of a porcine congenital single-sided deafness (CSSD) pedigree.MethodsClick auditory brainstem response (ABR), full-frequency ABR, and distortion product otoacoustic emission (DPOAE) were used to assess the hearing phenotype of the strain. Tympanogram was used to assess the middle ear function since birth. Celloidin embedding–hematoxylin–eosin (CE-HE) stain and scanning electron microscopy (SEM) were used to study the pathological changes of cochlear microstructures. Chi-square analysis was used to analyze the relation between hearing loss and other phenotypes.ResultsThe mating mood of CSSD with CSSD was most efficient in breeding-targeted CSSD phenotype (47.62%), and the prevalence of CSSD reached 46.67% till the fifth generation, where 42.22% were bilateral hearing loss (BHL) and 9.00% were normal hearing (NH) individuals. Hearing loss was proved to have no relation with coat color (P = 0.0841 > 0.05) and gender (P = 0.4621 > 0.05) by chi-square analysis. The deaf side of CSSD offspring in the fifth generation had no relation with that of their maternal parent (P = 0.2387 > 0.05). All individuals in this strain exhibited congenital severe to profound sensorineural hearing loss with no malformation and dysfunction of the middle ear. The good hearing ear of CSSD stayed stable over age. The deaf side of CSSD and BHL presented cochlear and saccular degeneration, and the hair cell exhibited malformation since birth and degenerated from the apex to base turn through time. The pathology in BHL cochlea progressed more rapidly than CSSD and till P30, the hair cell had been totally gone. The stria vascularis (SV) was normal since birth and degenerated through time and finally exhibited disorganization of three layers of cells.ConclusionThis inbred porcine strain exhibited high and stable prevalence of CSSD, which highly resembled human non-syndromic CSSD disease. This porcine model could be used to further explore the etiology of CSSD and serve as an ideal tool for the studies of the effects of single-sided hearing deprivation on neural, cognitive, and behavioral developments and the benefits brought by CI in CSSD individuals.

• African mole-rats have only low-frequency hearing; an acoustic fovea is known in one species. • It has been claimed that, uniquely among mammals, certain mole-rats lack evoked otoacoustic emissions and hair-cell active processes. • We describe robust evoked emissions (DPOAE and SFOAE), with highest amplitudes at the frequencies of the acoustic fovea. • In the past, the narrow and strongly curved ear canals of African mole-rats might have complicated successful recording. African mole-rats display highly derived hearing that is characterized by low sensitivity and a narrow auditory range restricted to low frequencies < 10 kHz. Recently, it has been suggested that two species of these rodents do not exhibit distortion product otoacoustic emissions (DPOAE), which was interpreted as evidence for a lack of cochlear amplification. If true, this would make them unique among mammals. However, both theoretical considerations on the generation of DPOAE as well as previously published experimental evidence challenge this assumption. We measured DPOAE and stimulus-frequency otoacoustic emissions (SFOAE) in three species of African mole-rats (Ansell's mole-rat - Fukomys anselli ; Mashona mole-rat - Fukomys darlingi ; naked mole-rat - Heterocephalus glaber) and found unexceptional otoacoustic emission values. Measurements were complicated by the remarkably long, narrow and curved external ear canals of these animals, for which we provide a morphological description. Both DPOAE and SFOAE displayed the highest amplitudes near 1 kHz, which corresponds to the region of best hearing in all tested species, as well as to the frequency region of the low-frequency acoustic fovea previously described in Ansell's mole-rat. Thus, the cochlea in African mole-rats shares the ability to generate evoked otoacoustic emission with other mammals. [Display omitted] [ABSTRACT FROM AUTHOR]

• Mutations in connexin proteins cause congenital nonsyndromic and syndromic hearing loss. • The roles of connexins in age-related hearing loss (ARHL) are largely unexplored. • We found that Cx30 and Cx43 decrease expressions with age in the CBA/CaJ mouse cochlea. • We discovered that aldosterone treatment provides protective effects for Cx30and Cx43. • These results indicate that connexin protein declines are likely mechanisms of ARHL. Age-related hearing loss (ARHL), also known as presbycusis, is the number one communication disorder for aging adults. Connexin proteins are essential for intercellular communication throughout the human body, including the cochlea. Mutations in connexin genes have been linked to human syndromic and nonsyndromic deafness; thus, we hypothesize that changes in connexin gene and protein expression with age are involved in the etiology of ARHL. Here, connexin gene and protein expression changes for CBA/CaJ mice at different ages were examined, and correlations were analyzed between the changes in expression levels and functional hearing measures, such as ABRs and DPOAEs. Moreover, we investigated potential treatment options for ARHL. Results showed significant downregulation of Cx30 and Cx43 gene expression and significant correlations between the degree of hearing loss and the changes in gene expression for both genes. Moreover, dose-dependent treatments utilizing cochlear cell lines showed that aldosterone hormone therapy significantly increased Cx expression. In vivo mouse treatments with aldosterone also showed protective effects on connexin expression in aging mice. Based on these functionally relevant findings, next steps can include more investigations of the mechanisms related to connexin family gap junction protein expression changes during ARHL; and expand knowledge of clinically-relevant treatment options by knowing what specific members of the Cx family and related inter-cellular proteins should be targeted therapeutically. [ABSTRACT FROM AUTHOR]

Objective: Hearing impairment is a reported late complication of diabetes mellitus (DM). Previous studies have suggested that microangiopathic complications may cause cochlear nerve function deterioration. We evaluated the auditory brainstem evoked responses (ABRs) and distortion product otoacoustic emission (DPOAE) results according to the presence of DM in subjects with normal hearing.Methods: A cross-sectional comparative study was conducted from January 2016 to January 2018. Auditory function tests including ABR and DPOAE were performed for outpatients complaining of unilateral tinnitus. All of analyses were conducted in ears without tinnitus on contralateral side of tinnitus ears. We included subjects showing hearing thresholds within 25 dB at 0.5, 1k, 2k, and 4k on pure tone audiometry. 45 ears in patients with type 2 diabetes mellitus and 85 ears in non-diabetic patients were finally enrolled in our study.Results: Diabetic subjects showed significantly more prolonged absolute peak latencies (I, III, V) and inter-peak latencies (I-V, III-V) than non-diabetic subjects. However, there was no significant difference in the inter-peak latency (I-III) between these two groups. Diabetic subjects also showed significantly lower amplitudes at f2 frequencies of 1001, 1200, 1587, 4004, 5042, and 6348 Hz than non-diabetic subjects. Additionally, the prevalence of a DPOAE response, defined as 3 dB above the noise floor, was significantly lower in diabetic subjects than that in non-diabetic subjects.Conclusion: Diabetic patients with normal hearing can still have abnormal ABR and DPOAE results due to diabetic neuroangiopathy. ABR and DPOAE assessments can help in detecting subclinical auditory dysfunction, which precedes the manifestation of hearing impairment in diabetic patients. [ABSTRACT FROM AUTHOR]

Copyright of Otorhinolaryngology (25288253) is the property of Ukrainian Oto-Rhino-Laryngological Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Analyzing the association between pure tone audiometry and distortion of otoacoustic emission (DPOAE) in students after shooting practice. Methods: This study was conducted at the East Java State Police Academy, Mojokerto, Indonesia, from August 2018 to January 2019. Participants were examined for pure tone audiometry and DPOAE two weeks after shooting training. Participants previously had undergone shooting training for 5 months, with schedule of 4 times per week. The statistical test used an independent t test or Mann Whitney test with p < 0.05. Results: All participants were men, with an average pure tone audiometry value of 27.50 ± 10.43 dB. The results of pure tone audiometry examination found that most participants had normal hearing (58.00%). This finding was inversely proportional to the results of DPOAE examination, in which most participants had “Refer” (78.00%). The mean pure tone audiometry value on participants with DPOAE “Refer” was 20.36 ± 3.47 dB and DPOAE “Pass” was 29.51 ± 10.87 dB (p = 0.008). Most participants had “Refer” DPOAE with normal pure tone audiometry as much as 36.00%, followed by participants with “Refer” DPOAE but mild hearing loss of pure tone audiometry as much as 24.00% (p = 0.002). Conclusion: There is a significant association between pure tone audiometry with DPOAE. Many participants have normal audiometry but “Refer” DPOAE, and followed by participants experiencing mild hearing loss with “Refer” DPOAE. [ABSTRACT FROM AUTHOR]

Background: Distortion product otoacoustic emissions evaluate the function of outer hair cells in the cochlea. The present study aimed to compare distortion product otoacoustic emissions between normal hearing adult human and rat to better understand their differences. Materials and Methods: In this study, signal to noise ratio of distortion product otoacoustic emissions was evaluated and the results of normal hearing persons (n=60) and rats (n=30) were evaluated in similar conditions at of 2, 3, 4, and 5 KHz. Results: The difference between the two groups was significant in most frequencies except 3 KHz. In rats, a higher signal to noise ratio was observed at 4 and 5 KHz and a lower ratio at 2 KHz. There was no significant difference among different frequencies in human samples. Conclusion: Significant differences in distortion product otoacoustic emissions in the two groups may demonstrate the different mechanisms for cochlear function in human and rat. This result may indicate the need for extra cautions in using rats as an animal model.

Background/aim: Ischemia is insufficient blood flow to provide adequate oxygenation. In the present study, we aimed to show whether acute hypoxia has a critical oxygen value that may lead to the deterioration of cochlear function. Materials and methods: Under general anesthesia, prehypoxic signal-to-noise ratios were determined by distortion product otoacoustic emissions (DPOAE). The oxygen saturation (SaO2) values of rats were monitored with an oxygen saturation probe. Rats were injected with an extra dose of anesthetic agent, and SaO2 was reduced. DPOAE values in SaO2 100–90, 90–80, 80–70, and 70–60 posthypoxic values were measured and compared statistically with prehypoxic values. Results: At 3000 and 4000 Hz, SaO2 70–60 values measured after the hypoxia were observed to be statistically significantly lower than the values measured before the hypoxia. At 6000 and 8000 Hz, SaO2 80–70 and 70–60 values measured after the hypoxia were observed to be statistically significantly lower than the values measured before the hypoxia. At 10,000 Hz, all of the values measured after the hypoxia were observed to be statistically significantly lower than the values obtained before the hypoxia. Conclusion: Many studies have been conducted on the effects of hypoxia on the inner ear. It remains unclear how fluctuations in DPOAE levels affect hearing in clinical trials when the SaO2 starts to decrease. Although hypoxia has been implicated in the etiology of sudden hearing loss and tinnitus, the effects of acute hypoxia on the cochlea are still uncertain. Further studies are needed on this subject. [ABSTRACT FROM AUTHOR]

Objective: Distortion product otoacoustic emissions (DPOAEs) are sensitive to early indices of cochlear pathology. Pathology to the cochlea is in part mediated by ischaemic related mechanisms. We propose that DPOAEs may provide an objective measure of cardiovascular risk. Design: Cross-sectional. Study sample: The relationships between stroke risk and DPOAEs of 1,107 individuals from the Jackson Heart Study (JHS), an all-African-American cohort, were assessed. Linear regression models were used for analysis among all participants and delimited to normal hearing, defined as either a pure-tone threshold average of 500, 1000, 2000, and 4000 Hz (PTA4) ≤ 25 dBHL or pure-tone thresholds for all individual tested frequencies for each ear (500, 1000, 2000, 4000, and 8000 Hz) ≤ 25 dBHL. Results: We observed a significant inverse relationship between DPOAE amplitudes and stroke risk scores in the pooled cohort and in the subgroups with normal hearing defined by pure tone thresholds. Participants in the high-risk group had significantly lower DPOAE amplitudes than those in the low stroke risk group. Conclusions: Our results indicate that auditory dysfunction as measured by DPOAEs are related to stroke risk. Further prospective studies are needed to determine if DPOAEs could be used as a predictive tool for cardiovascular disease. [ABSTRACT FROM AUTHOR]

Objective: To describe the auditory function in early old age in detail based on both psychoacoustic and physiological measures, and to investigate the prevalence of specific audiological and otological pathologies. Design: An unscreened subsample from a population-based geriatric investigation was examined with otoscopy; tympanometry; pure-tone audiometry; word-recognition-in-noise test; distortion-product otoacoustic emissions; and auditory-evoked brainstem responses. Audiometric subtypes and diagnoses were established based on set criteria. The association between word scores and ABR was examined with linear regression analysis. Study Sample: 251 persons aged 70 (113 men, 138 women, born in 1944) that were representative of the inhabitants of the city of Gothenburg. Results: The prevalence of conductive pathology was 2% versus 49% for cochlear and 2% for auditory-neural pathology. Four percent had indeterminate type. Cochlear dysfunction was present in the majority of ears and around 20% performed worse-than-expected on speech testing. Poor performance on the speech in noise test was associated with prolonged interpeak latency interval of ABR waves I-V. Conclusion: Specific otological and audiological pathologies, other than cochlear hearing loss, are rare in the general population at age 70. Additionally, there is subtle evidence of age-related decline of the auditory nerve. Longitudinal follow-up would be of great interest. [ABSTRACT FROM AUTHOR]

Long-term exposure to aminoglycoside such as kanamycin to cochlear cells is known to be associated with damage to outer hair cells in the organ Corti and type 1 sensory hair cells in the vestibular organs which ultimately causes permanent damage to hair cells. Hair cell damage occurs from the basal cochlea (high frequency area) to the apex cochlea (low frequency area) and followed by damage from the auditory nerve. Evaluation of cochlear dysfunction on multidrug resistant tuberculosis (MDR TB) patients have been rarely reported in the literature based on distortion product otoacoustic emission (DPOAE). Objectives: To prove cochlear dysfunction after kanamycin injection in MDR TB patient based on DPOAE examination of the overall frequencies and specific frequency. This was an observational longitudinal analytic with pre and post design without control group conducted in the infection division of MDR TB Outpatients Pulmonology Department and Otorhinolaryngology Community division of ORL-HNS Department, Dr. Soetomo General Hospital, Surabaya, within 3 months in 2018, 15 ear with the best baseline examination were taken by consecutive sampling and statistical analysis for cochlear dysfunction based on overall frequency and specific frequency DPOAE examination using Mc Nemar test. Based on DPOAE examination of overall frequencies there was no cochlear dysfunction (p>0.05) but a significant difference was found at frequency of 10,000 Hertz (Hz) (p=0.002). On ototoxicity monitoring there was no cochlear dysfunction after 4 weeks Kanamycin injection but cochlear dysfunction occurs at a specific frequency of 10,000 Hz. [ABSTRACT FROM AUTHOR]

Introduction Distortion product otoacoustic emissions (DPOAEs) can be helpful in estimating the hearing thresholds by extrapolating the DPOAE input/output function with the help of scissor paradigm, and thus the following study aims at assessing its reliability by comparing DPOAE thresholds with those obtained by behavioral responses at pure tones on various frequencies. Materials and Methods Fifty participants having normal hearing sensitivity were included in the study. Pure tone (PT) audiometry was carried out on all participants to determine PT thresholds in both ears. DPOAE threshold test was administered and thresholds at 1, 2, 4, and 8 kHz were compared accordingly. Results The result indicated significant difference between the two methods of threshold estimation where the mean difference was found to be 3 decibel (dB) and 4 dB for left and right ears, respectively. Shapiro-Wilk test revealed normal distribution (p > 0.05) of the data. Hence, parametric paired t-test was performed, which revealed significant difference between PT and distortion product thresholds. Conclusion Study concludes as having good clinical applicability in assessing neonates and infants. [ABSTRACT FROM AUTHOR]

DPOAEs are acoustic energy within the external auditory canal (EAC) arising from the non-linear interaction within the cochlea; of 2 pure tones presented simultaneously; of primary frequencies f1 and f2. DPOAEs are recorded in nearly any normal-hearing subject and in patients with hearing loss up to 50 dBHL while recordings may be deceiving in the presence of severe to profound hearing loss. To determine the intensity levels of f1 and f2 at which DPOAEs truly reflect the active metabolic processes within the cochlea. University Hospital Prospective One-hundred and forty ears were categorized into three groups; A (n = 50), B (n = 50) and C (n = 40); according to subjects' age (12 to 18, 2 to 12 and <2 years, respectively). A fourth group D was included; which entailed recordings from a dummy cavity simulating a child's external auditory canal. Each group was further subdivided into two subgroups according to hearing levels; either normal or severe to profound hearing loss. DP-grams were interpreted at 3 points/octave steps for all groups and reviewed as 'Pass' or 'Fail' according to set criteria. Stimulus levels were adjusted such that L1 exceeded L2 by 10 dB. Start levels for L1 and L2 were 80 and 70 dBSPL. Levels were reduced simultanueously in 5 dB steps for the following recordings; to reach 65 and 55 for the last recording. Using the higher three stimulation levels, all subgroups had 'Pass' DP grams. On using the last and lowest recording level, only subgroups of normal hearing ears had 'Pass' DP grams; while subgroups of ears with sensorineural hearing loss (SNHL) demonstrated 'Failed' DP grams at all frequencies. For audiometric screening purposes, DPOAEs show to be rather insensitive to hearing loss at higher stimulation levels and may reveal false positive results. [ABSTRACT FROM AUTHOR]

Objective: Because of their high metabolic activity and low-resting oxygen tension, the organs of the inner ear are vulnerable to hypoxia, a condition that occurs repetitively in obstructive sleep apnea-hypopnea syndrome (OSAHS). The present study aimed to investigate the inner ear function of patients with OSAHS. Methods: A total of 58 patients with OSAHS (116 ears) and 20 adults without OSAHS were enrolled in the present study. The clinical features, such as air-conduction thresholds, auditory brainstem response (ABR, 11 times/s and 51 times/s stimulation rates), and distorted products otoacoustic emission (DPOAE), were evaluated and compared between these two groups. Results: Air-conduction thresholds at 4 kHz and 8 kHz were higher in patients with OSAHS compared with controls (P < 0.001). At the rate of 11 times per second, biauricular wave I latencies and wave V latencies in the OSAHS group were longer than those in the control group (1.51 ± 0.13 vs. 1.33 ± 0.07 ms, P < 0.001; 5.65 ± 0.23 vs. 5.53 ± 0.23 ms, P = 0.0016). At the rate of 51 times per second, biauricular wave I latencies and wave V latencies in the OSAHS group were longer than those in the control group (1.64 ± 0.12 vs. 1.44 ± 0.06 ms, P = 0.0001; 5.92 ± 0.26 vs. 5.80 ± 0.18 ms, P = 0.0077). However, there was no significant difference in the wave I and wave V interval between these two groups (P = 0.10). DPOAE amplitude was significantly reduced in OSAHS patients, although no hearing loss was observed. Conclusion: High-frequency hearing loss was detected in adults with severe OSAHS, and wave I latencies and wave V latencies of ABR were prolonged. [ABSTRACT FROM AUTHOR]

Exposure to noise can lead to anatomical, nonauditory, and auditory impacts. The auditory influence of noise exposure is manifested in the form of Noise-induced hearing loss (NIHL). The current study aimed at present a signal to noise ratio model of otoacoustic emission of rats' ears in the light of the combined effect of sound pressure level, sound frequency, exposure time, and potassium concentration of the used water. In total, 36 adult male rates, whose age varied from 3 to 4 months and had a weight of 200 ± 50 g, were randomly divided into 12 groups, with each group consisting of 3 rats. The rats in both groups (case and control groups) were exposed to SPLs of 85, 95, and 105 dB, emitted from sources that generated white noise. A distortion product otoacoustic emission (DPOAE) machine (4000 I/O manufactured by Homoth of Germany) was utilized to gauge the signal to noise ratio (SNR) of otoacoustic emissions of rats' ears at various frequencies in an acoustic room. The inclusion criterion was SNR = 6 dB. The collected data were fed into the Statistical Package for Social Sciences (SPSS) version 18, followed by conducting descriptive and inferential data analysis procedures. The results of SNR analysis indicated that over 82% of all data had SNRs that were equal to or greater than 6 dB. These data were considered as acceptable response. Furthermore, SPL and sound frequency had significant associations with SNR (P < 0.0001). Exposure time also significantly correlated with SNR (P = 0.008). However, the potassium concentration of the used water had no significant correlation with SNR (P = 0.97). High sound pressure levels result in lower DPOAE. Furthermore, higher frequency leads to higher SNR. On the contrary, longer exposure time reduces SNR. Finally, the potassium concentration of the used water has no effect on SNR. [ABSTRACT FROM AUTHOR]

Background: Kanamycin treatment is mainly used in multidrug-resistant tuberculosis (MDR-TB) patients. Hearing impairment associated along with the treatment leads to be permanently. Audiology assessments and monitoring may benefits to detect early on hearing loss. This study aimed to determine the evaluation of hearing alteration after kanamycin injection in the first month treatment. Method: We conducted a prospective study, observational longitudinal analytic with pre and post design in patients treated with kanamycin-based regimens in MDR TB Outpatients Pulmonology Department Dr. Soetomo general hospital Surabaya. Assessment of hearing result using Pure Tone Audiometry and DPOAE, compared between baseline data and after 4 weeks treatments. Statistical analysis for hearing threshold and cochlear dysfunction based on overall frequency and specific frequency DPOAE examination, using Wilcoxon ranks test and Mc Nemar test. Results: A total of 15 patients (8 males and 7 females) with confirmed diagnosis of MDR-TB were included in this study conducted within 3 months in 2018.There were 15 ears represented with based line and compared to 4 weeks after treatment, showed on Audiometry and DPOAE on overall frequencies, found no significant difference (p > 0.05), but in DPOAE at frequency of 10,000 Hertz (Hz) was found a significant difference (p = 0.002). Conclusion: DPOAEat high frequency (10,000 Hz) may benefits for early detection on hearing impairment. A baseline data with DPOAE is recommended, besides Audiometry for ototoxicity monitoring in Kanamycin treatment in MDRTB patients. [ABSTRACT FROM AUTHOR]

Introduction: Age-related hearing loss is an important risk factor for cognitive decline. However, audiogram thresholds are not good estimators of dementia risk in subjects with normal hearing or mild hearing loss. Here we propose to use distortion product otoacoustic emissions (DPOAEs) as an objective and sensitive tool to estimate the risk of cognitive decline in older adults with normal hearing or mild hearing loss., Methods: We assessed neuropsychological, brain magnetic resonance imaging, and auditory analyses on 94 subjects > 64 years of age., Results: We found that cochlear dysfunction, measured by DPOAEs-and not by conventional audiometry-was associated with Clinical Dementia Rating Sum of Boxes (CDR-SoB) classification and brain atrophy in the group with mild hearing loss (25 to 40 dB) and normal hearing (<25 dB)., Discussion: Our findings suggest that DPOAEs may be a non-invasive tool for detecting neurodegeneration and cognitive decline in the older adults, potentially allowing for early intervention., Competing Interests: None of the authors declare any conflict of interest. Author disclosures are available in the supporting information., (© 2024 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Aim: In this study, it was aimed to experimentally investigate the protective effects of melatonin in the cisplatin-induced ototoxicity. Material and Methods: Ten Wistar-albino rats were included in the study. Two equal groups were generated randomly as cisplatin and melatonin groups. Rats' underwent Auditory Brainstem Response (ABR) and Distortion Product Otoacoustic Emission (DPOAE) testing before the drug administration and the results were recorded. Both tests were repeated 72 hours after the cisplatin administration in all rats. Results: Significant difference was found between the I-IV interval values before the treatment and after the treatment both in cisplatin and melatonin group. As well as the significant difference in hearing threshold value changes, statistically, significant differences in ABR-I and ABR-IV interval variations were also seen between the cisplatin and melatonin groups. A statistically significant decrease was found between the initial and final control SNR (signal-to-noise ratio) levels within the cisplatin group in the evaluations at 2000Hz, 3000Hz and 4000Hz. Statistically, significant differences were observed between SNR levels when the melatonin group was compared with the cisplatin group. Conclusion: Melatonin appears to reduce cisplatin-induced ototoxicity in rats. Although, the use of supplementary therapies targeting to reduce the toxic effects in clinical studies is still a controversial point. [ABSTRACT FROM AUTHOR]

Purpose: In this study, we aimed to investigate whether there is any positive or negative correlation between high-frequency distortion product otoacoustic emission (DPOAE) values and mean platelet volume (MPV) and neutrophil/lymphocyte ratio (NLR) in tinnitus patients. Methods: The study was performed with 52 volunteers (27 females, 25 males) aged between 35 and 50 years who presented with tinnitus to the otolaryngology outpatient clinic of a tertiary care center. Pure voice audiometric examination, DPOAE measurement, complete blood count values of the study participants were examined. Results: In both ears, a significant and negative correlation was observed between 4000 and 8000 Hz airway and 4000 Hz bone conduction pathways with NLR rates (p < 0.05). A statistically significant relationship was found between the bone conduction pathway PTA and discrimination values for both ears and NLR s (p < 0.05). A positive correlation was detected between NLRs and DPOAE measurements recorded at 4444 Hz, 5000 Hz, 8000 Hz, 8889 Hz, 10,000 Hz and 11,429 Hz frequencies in the right and 4444 Hz, 5000 Hz, 6154 Hz, 8000 Hz, 10,000 Hz and 11,429 Hz frequencies in the left ears, respectively (p < 0.05). Conclusions: We concluded that there is a significant correlation between high-frequency pure tone audiometry measurements and high frequency DPOAE measurements and NLR. Further studies are needed to determine the utility of NLR as a marker for the recognition and follow-up of hearing loss in patients with tinnitus. [ABSTRACT FROM AUTHOR]