Hearing Thresholds Research Articles

Therapeutic efficacy of methylprednisolone sodium succinate via diverse administration routes for mid- to high-frequency sudden sensorineural hearing loss

BACKGROUND Sudden sensorineural hearing loss (SSNHL), characterized by a rapid and unexplained loss of hearing, particularly at moderate to high frequencies, presents a significant clinical challenge. The therapeutic use of methylprednisolone sodium succinate (MPSS) via different administration routes, in combination with conventional medications, remains a topic of interest. AIM To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid- to high-frequency SSNHL. METHODS The medical records of 109 patients with mid- to high-frequency SSNHL were analyzed. The patients were divided into three groups based on the route of administration: Group A [intratympanic (IT) injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection], Group B (intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection), and Group C (single IT injection of MPSS). The intervention effects were compared and analyzed. RESULTS The posttreatment auditory thresholds in Group A (21.23 ± 3 .34) were significantly lower than those in Groups B (28.52 ± 3.36) and C (30.23 ± 4.21; P < 0.05). Group A also exhibited a significantly greater speech recognition rate (92.23 ± 5.34) than Groups B and C. The disappearance time of tinnitus, time to hearing recovery, and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C (P < 0.05). The total effective rate in Group A (97.56%) was significantly greater than that in Groups B and C (77.14% and 78.79%, χ 2 = 7.898, P = 0.019). Moreover, the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B (4.88%, 3.03% vs 2.57%, χ 2 = 11.443, P = 0.003), and the recurrence rate in Group A was significantly lower than that in Groups B and C (2.44% vs 20.00% vs 21.21%, χ 2 = 7.120, P = 0.028). CONCLUSION IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS. This approach effectively improves patients' hearing and reduces the risk of disease recurrence.

Effect of External Ear Deformity on Hearing in Wrestlers.

Cauliflower ear in wrestlers can lead to hearing impairment. This study primarily aims to assess the hearing of wrestlers with bilateral cauliflower ears and determine their external ear canal (EEC) resonance frequencies. Our second aim is to evaluate their hearing quality, speech, and spatial perception. This study included 28 male wrestlers aged 18-35 years with bilateral cauliflower ears, as well as 27 male participants in the control group with no wrestling history. The participants' hearing thresholds were determined across the frequency range of 125-16000 Hz for air-conduction and 500-4000 Hz for bone conduction. EEC resonance frequencies were measured. Additionally, all participants completed the Turkish version of the Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire. Wrestlers with cauliflower ears exhibited significantly higher hearing thresholds, particularly at frequencies above 4000 Hz (p < .05). Analysis of EEC resonance showed a shift to higher frequencies in the second resonance peak of the right ear (p < .001) and the first resonance peak of the left ear (p = .045). SSQ scores revealed that wrestlers had higher spatial perception (p = .046), hearing quality (p = .004), and general scores (p = .042) in comparison to the control group. Blunt traumas in wrestlers, leading to cauliflower ear, can result in hearing loss. Moreover, deformities in the external ear affect the resonance frequencies of the EEC. Therefore, it is crucial to advocate for the use of ear protection equipment among wrestlers. When fitting hearing aids, attention should be given to changes in the EEC resonance frequency.

Word-in-noise perception test in children

Background The word-in-noise discrimination test evaluates the phonological aspect of speech based on the detection of the vowels. While word-in-noise perception (WINP) test is one of the speech perception exams and evaluates the ability to understand the meaning of words by discovering the consonants.Until now, all word-in-noise tests have assessed speech discrimination performance, and for the first time, the normal values of the WINP test for adults have been determined. Since the normal values of WINP scores in children have not been reported, our research aimed to determine the normal values of the WINP test in children aged 5 to 13 years.In this cross-sectional study, 120 Persian speaking Iranain children with normal hearing thresholds were evaluated from the beginning to the end of spring 2023. We divided them into 4 age groups (A = 5–7 < years, B = 7–9 < years, C = 9–11 < years, D = 11–13 < years). The evaluations included general audiology tests and WINP tests using homtonic-monosyllabic words (HMWs) at a signal-to-noise ratio of 5 dB.ResultsSignificant difference was observed between the mean scores of the WINP test in age group A (54%) compared to age group B (66%), (Pv = 0.04). Also, the differences between the mean scores of age group A compared to age groups C (70%) and D (69%) were significant (Pv = 0.01, Pv = 0.03).ConclusionsThis article presented the norm values of WINP test scores for Persian speaking Iranian children aged 5 to 13 years. The norm values of WINP test scores in the age group of 5–7 years were lower than in the age groups of 7–13 years. The biggest change in the performance of speech perception in noise was observed in the age range of 7–9 years.

Audiological Profile of a Rare Case with 1kHz Notch Audiogram.

A notch is defined as the frequency point at which hearing loss is greater than 15 dB when compared to one octave above and below. C3 dip or 1kHz notch is rarely seen and not much information is known about the clinical profile of such condition. The aim of this case report is to highlight the audiological profile of a case with 1kHz notch and discuss the possible causes for the same. Case A (16 yrs) was referred with a complaint of hearing loss and speech understanding difficulty specially at school. The teen had taken multiple medications for several health related issues like malaria, appendicitis and the understanding difficulty was evident during this period. Detailed audiological evaluation revealed a significant C3 dip in the right ear and normal hearing sensitivity in the left ear. Evidences from literature suggests strong correlation between drugs like Cefotetan, cefotaime, piperacillin, ampicillin (appendicitis treatment) and chloroquine (malaria) and hearing loss. Hence, we concluded that the possible cause of 1khz is ototoxic medication.

Efficacy and Mechanisms of Antioxidant Compounds and Combinations Thereof against Cisplatin-Induced Hearing Loss in a Rat Model.

Cisplatin is an election chemotherapeutic agent used for many cancer treatments. Its cytotoxicity against neoplastic cells is mirrored by that taking place in healthy cells and tissues, resulting in serious adverse events. A very frequent one is ototoxicity, causing hearing loss which may permanently affect quality of life after successful oncologic treatments. Exacerbated oxidative stress is a main cytotoxic mechanism of cisplatin, including ototoxicity. Previous reports have shown antioxidant protection against cisplatin ototoxicity, but there is a lack of comparative studies on the otoprotectant activity and mechanism of antioxidant formulations. Here, we show evidence that a cocktail of vitamins A, C, and E along with Mg++ (ACEMg), previously shown to protect against noise-induced hearing loss, reverses auditory threshold shifts, promotes outer hair cell survival, and attenuates oxidative stress in the cochlea after cisplatin treatment, thus protecting against extreme cisplatin ototoxicity in rats. The addition of 500 mg N-acetylcysteine (NAC), which, administered individually, also shows significant attenuation of cisplatin ototoxicity, to the ACEMg formulation results in functional degradation of ACEMg otoprotection. Mg++ administered alone, as MgSO4, also prevents cisplatin ototoxicity, but in combination with 500 mg NAC, otoprotection is also greatly degraded. Increasing the dose of NAC to 1000 mg also results in dramatic loss of otoprotection activity compared with 500 mg NAC. These findings support that single antioxidants or antioxidant combinations, particularly ACEMg in this experimental series, have significant otoprotection efficacy against cisplatin ototoxicity. However, an excess of combined antioxidants and/or elevated doses, above a yet-to-be-defined "antioxidation threshold", results in unrecoverable redox imbalance with loss of otoprotectant activity.

Automated hearing loss type classification based on pure tone audiometry data

Hearing problems are commonly diagnosed with the use of tonal audiometry, which measures a patient’s hearing threshold in both air and bone conduction at various frequencies. Results of audiometry tests, usually represented graphically in the form of an audiogram, need to be interpreted by a professional audiologist in order to determine the exact type of hearing loss and administer proper treatment. However, the small number of professionals in the field can severely delay proper diagnosis. The presented work proposes a neural network solution for classification of tonal audiometry data. The solution, based on the Bidirectional Long Short-Term Memory architecture, has been devised and evaluated for classifying audiometry results into four classes, representing normal hearing, conductive hearing loss, mixed hearing loss, and sensorineural hearing loss. The network was trained using 15,046 test results analysed and categorised by professional audiologists. The proposed model achieves 99.33% classification accuracy on datasets outside of training. In clinical application, the model allows general practitioners to independently classify tonal audiometry results for patient referral. In addition, the proposed solution provides audiologists and otolaryngologists with access to an AI decision support system that has the potential to reduce their burden, improve diagnostic accuracy, and minimise human error.

An Open-Source Deep Learning-Based GUI Toolbox For Automated Auditory Brainstem Response Analyses (ABRA).

In this paper, we introduce a new, open-source software developed in Python for analyzing Auditory Brainstem Response (ABR) waveforms. ABRs are a far-field recording of synchronous neural activity generated by the auditory fibers in the ear in response to sound, and used to study acoustic neural information traveling along the ascending auditory pathway. Common ABR data analysis practices are subject to human interpretation and are labor-intensive, requiring manual annotations and visual estimation of hearing thresholds. The proposed new Auditory Brainstem Response Analyzer (ABRA) software is designed to facilitate the analysis of ABRs by supporting batch data import/export, waveform visualization, and statistical analysis. Techniques implemented in this software include algorithmic peak finding, threshold estimation, latency estimation, time warping for curve alignment, and 3D plotting of ABR waveforms over stimulus frequencies and decibels. The excellent performance on a large dataset of ABR collected from three labs in the field of hearing research that use different experimental recording settings illustrates the efficacy, flexibility, and wide utility of ABRA.

Hyperacusis questionnaire and event-related potential correlation in migraine patients

This study aims to investigate auditory hypersensitivity and cortical function in migraine patients using the Hyperacusis Questionnaire and the Event-Related Potential (ERP) technique. The study analyzes alterations in the latency and amplitude of the event-related potentials MMN and P300 components. The findings contribute to a better understanding of the physiological relationship between migraine and auditory hypersensitivity. Seventeen migraine patients were admitted to the outpatient clinic of the Department of Otorhinolaryngology-Head and Neck Surgery at Peking University People’s Hospital from June 2023 to September 2023. Nineteen matched healthy subjects were also selected. All participants underwent the pure tone audiometry and the auditory brainstem response test to determine hearing thresholds, the Hyperacusis Questionnaire, the Tinnitus Handicap Inventory, and an ERP examination. The Oddball classical paradigm was used as the stimulation task, and electroencephalography signals were recorded synchronously. The scores of the Hyperacusis Questionnaire, latency and amplitude of MMN and P300 component were compared between the migraine group and the control group, and their correlation was analyzed. The latency of MMN at the Fz and Cz sites in migraine patients was significantly shorter than that in the control group (P < 0.05), and the amplitudes were significantly higher than those in the control group (P < 0.05). The variances in latency and amplitude of P300 at Cz and Pz sites in migraine patients were not statistically significant when compared with the control group. (P > 0.05). The Hyperacusis Questionnaire was negatively correlated with MMN latency, with a correlation coefficient of − 0.374 (P = 0.025), and positively correlated with MMN amplitude, with a correlation coefficient of 0.378 (P = 0.023). There was no significant similarity between the Hyperacusis Questionnaire and P300 latency and amplitude (P > 0.05). Overall, auditory hypersensitivity was enhanced in individuals with migraines compared to healthy individuals, leading to faster information processing, while there may be less impairment in cognitive function.

Contribution of Treatment with Ear Popper for Hearing in Children with Middle Ear Effusion.

we aim to assess the contribution of the EarPopper device to hearing in children with middle ear effusion (MEE). The study has three parts, including 1. tympanometry and audiometry before and six weeks after using the EarPopper to evaluate the treatment's effect over time compared to a control group; 2. tympanometry before and immediately after using the EarPopper to evaluate immediate changes in middle ear pressure (MEP); 3. length of effect 90 min after use to assess pressure fluctuations over time. Part 1 was a follow-up six weeks after using the device, and the patients in the study group that completed the study showed a significant improvement in hearing threshold. The average gain in hearing threshold ranged from 9.1 dB to 14 dB compared to the control group's max improvement of 1.1 dB. In addition, MEP was significantly improved in the study group, as most Type Bs improved to Type A and C. Part 2 was the tympanometry immediately after using EarPopper and showed the majority of Type Cs turned into Type As. The majority of Type Bs remained unchanged. Part 3 was a follow-up 90 min after use; Type Cs that had improved to Type A demonstrated a decrease in pressure and return to negative pressure. use of the EarPopper device for six weeks is associated with an improved hearing threshold and middle ear status.

Profile of metabolic damages in occupational hearing loss

Introduction: Early diagnosis of hearing loss is essential to minimize the social impact in relation to work routine and quality of life. Objective: Analyze the association between hearing loss in workers and metabolic diseases. Method: Retrospective cross-sectional study of secondary data on the use of medications in metabolic diseases, the data were collected in two occupational health clinics (C1 and C2) in Florianópolis - Santa Catarina (Brazil), from January 2020 to December 2022, considering references from exams from the year 2005. The data were organized in Microsoft Excel® spreadsheets and subsequently exported and analyzed using the MedCalc® statistical software version 22.006. Results: The data of 97 patients (71 men and 26 women) exposed to occupational noise (p = 0.0047), diagnosed with at least one metabolic disease (41.20%) and prevalence of ATC H class medications (p = 0.0465) and Losartan® (OR = 1.6976). Discussion and Conclusion: Occupational noise is the main auditory risk factor, and the presence of metabolic disease can influence hearing thresholds. To reduce the vulnerability of this population, it is necessary to promote, raise awareness and educate, using approaches related to health aspects at work.

Focus on the effect of nursing care combined with cognitive intervention and functional training on negative emotion, compliance and quality of life in elderly patients with sudden deafness: A retrospective study.

To explore the effects of focused solution nursing combined with cognitive intervention combined with functional training on negative emotions, compliance and quality of life in elderly patients with sudden deafness. A total of 160 patients with sudden deafness in the elderly who were treated in our hospital from January 2019 to May 2021 were selected as the objects of this retrospective study. Based on different treatment approaches, subjects were divided into a control group and an observation group. Due to reasons such as the COVID-19 pandemic and transfers, 10 cases were lost to follow-up. In total, 75 cases were ultimately lost from both the control and observation groups. The control group implements cognitive intervention and functional training, and the observation group adopts focused solution nursing care on the basis of the control group. Observe and compare the effects of negative emotions, psychological distress, air conduction threshold level, compliance and quality of life of the 2 groups of patients. The air conduction hearing threshold level of the 2 groups of patients after nursing was lower than that before nursing and the observation group was lower than the control group. The positive coping scores of the 2 groups were significantly increased, and the negative coping scores were both significantly reduced and the observation group was in the 2 indicators. The degree of change was greater than that of the control group (P < .05). After nursing, the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) of the observation group were lower than those of the control group (P < .05). The mental vitality score, social interaction score, emotional restriction score, and mental status of the observation group were significantly higher than those of the control group. The observation group's psychological compliance, activity compliance, dietary compliance, and treatment protocol compliance were significantly higher than those of the control group (P < .05). Adopting the focused solution model of nursing care can provide a better nursing recovery for elderly patients with sudden deafness, significantly improve the patient quality of life and anxiety and depression, improve patient compliance with treatment, and provide a certain reference for the nursing of elderly patients with sudden deafness.

Remote Field Application of Digital Technology for Hearing Assessments in a Cohort of Pediatric Germ Cell Tumor Survivors.

Childhood cancer survivors treated with platinum-based chemotherapy are at risk of treatment-induced hearing loss. Accurate evaluation of hearing thresholds has historically been limited to clinical audiometry, which is logistically challenging and expensive to include in epidemiologic studies. We evaluated the feasibility of using a remote, tablet-based hearing assessment in a cohort of pediatric germ cell tumor survivors treated with platinum-based chemotherapy. Survivors from the GCT Outcomes and Late effects Data (GOLD) study were recruited to the pilot study (n = 100). Study personnel conducted remote hearing assessments of standard and extended high frequency thresholds using validated tablet-based audiometry (SHOEBOX, Inc.). T tests and Wilcoxon rank-sum tests evaluated differences in assessment characteristics between children and adults. Agreement between self-reported and measured hearing loss was calculated using Cohen κ. We were able to reach 136/168 (81%) eligible participants, of which 100 (74%) agreed to participate. Successful completion of the remote hearing assessment was high [97%; 20 children (ages 7-17), 77 adults (ages 18-31)]. The mean assessment length was 37.6 minutes, and the mean turnaround time was 8.3 days. We observed hearing loss at standard frequencies in 21% of participants. Agreement between self-reported and measured hearing loss was significant (P value = 1.41 × 10-7), with 83.5% concordance. Hearing loss measured using the remote assessment aligns with self-reporting and rates of hearing loss reported in the literature for this population. Remote application of tablet-based audiometry is a feasible and efficacious method for measuring hearing in epidemiologic studies with participants spread across large geographic areas.

Longitudinal urinary neopterin is associated with hearing threshold change over time in independent older adults

Low-grade chronic inflammation is associated with many age-related conditions. Non-invasive methods to monitor low-grade chronic inflammation may improve the management of older people at risk of poorer outcomes. This longitudinal cohort study has determined baseline inflammation using neopterin volatility in monthly urine samples of 45 independent older adults (aged 65–75 years). Measurement of neopterin, an inflammatory metabolite, enabled stratification of individuals into risk categories based on how often in a 12-month period their neopterin level was raised. Hearing was measured (pure-tone audiometry) at baseline, 1 year and 3 years of the study. Results show that those in the highest risk category (neopterin raised greater than 50% of the time) saw greater deterioration, particularly in high-frequency, hearing. A one-way Welch’s ANOVA showed a significant difference between the risk categories for change in high-frequency hearing (W (3, 19.6) = 9.164, p = 0.0005). Despite the study size and duration individuals in the highest risk category were more than twice as likely to have an additional age-related morbidity than those in the lowest risk category. We conclude that volatility of neopterin in urine may enable stratification of those at greatest risk of progression of hearing loss.

Combination of static and dynamic neural imaging features to distinguish sensorineural hearing loss: a machine learning study.

Sensorineural hearing loss (SNHL) is the most common form of sensory deprivation and is often unrecognized by patients, inducing not only auditory but also nonauditory symptoms. Data-driven classifier modeling with the combination of neural static and dynamic imaging features could be effectively used to classify SNHL individuals and healthy controls (HCs). We conducted hearing evaluation, neurological scale tests and resting-state MRI on 110 SNHL patients and 106 HCs. A total of 1,267 static and dynamic imaging characteristics were extracted from MRI data, and three methods of feature selection were computed, including the Spearman rank correlation test, least absolute shrinkage and selection operator (LASSO) and t test as well as LASSO. Linear, polynomial, radial basis functional kernel (RBF) and sigmoid support vector machine (SVM) models were chosen as the classifiers with fivefold cross-validation. The receiver operating characteristic curve, area under the curve (AUC), sensitivity, specificity and accuracy were calculated for each model. SNHL subjects had higher hearing thresholds in each frequency, as well as worse performance in cognitive and emotional evaluations, than HCs. After comparison, the selected brain regions using LASSO based on static and dynamic features were consistent with the between-group analysis, including auditory and nonauditory areas. The subsequent AUCs of the four SVM models (linear, polynomial, RBF and sigmoid) were as follows: 0.8075, 0.7340, 0.8462 and 0.8562. The RBF and sigmoid SVM had relatively higher accuracy, sensitivity and specificity. Our research raised attention to static and dynamic alterations underlying hearing deprivation. Machine learning-based models may provide several useful biomarkers for the classification and diagnosis of SNHL.

Sialyllactose preserves residual hearing after cochlear implantation

In individuals with hearing loss, protection of residual hearing is essential following cochlear implantation to facilitate acoustic and electric hearing. Hearing preservation requires slow insertion, atraumatic electrode and delivery of the optimal quantity of a pharmacological agent. Several studies have reported variable hearing outcomes with osmotic pump-mediated steroid delivery. New drugs, such as sialyllactose (SL) which have anti-inflammatory effect in many body parts, can prevent tissue overgrowth. In the present study, the positive effects of the pharmacological agent SL against insults were evaluated in vitro using HEI-OC1 cells. An animal model to simulate the damage due to electrode insertion during cochlear implantation was used. SL was delivered using osmotic pumps to prevent loss of the residual hearing in this animal model. Hearing deterioration, tissue fibrosis and ossification were confirmed in this animal model. Increased gene expressions of inflammatory cytokines were identified in the cochleae following dummy electrode insertion. Following the administration of SL, insertion led to a decrease in hearing threshold shifts, tissue reactions, and inflammatory markers. These results emphasize the possible role of SL in hearing preservation and improve our understanding of the mechanism underlying hearing loss after cochlear implantation.

A Comparison of Hearing Thresholds, and the Resulting Prescribed Gain and Hearing Aid Outputs, Using Gold Standard Audiometry and the TympaHealth Hearing Assessment Tool.

Phone- and tablet-based hearing testing systems are now widely available. Here, we evaluated one such system from TympaHealth by comparing air conduction thresholds and resultant hearing aid targets and output, measured with the TympaHealth system with those measured using standard audiometry. The hearing thresholds of 35 adults were measured using standard audiometry and the TympaHealth system. Each set of thresholds was used to generate NAL-NL2 targets and program a hearing aid. The data from each system were compared. Bland-Altman analyses showed overall mean differences between thresholds measured with each system to be small, with 85% of TympaHealth thresholds being within ±5 dB of the standard audiometric thresholds, although TympaHealth thresholds were higher (poorer) than the standard audiometric thresholds. The hearing aid targets and gains generated from the standard audiometric thresholds were lower (less amplification) than those generated from the TympaHealth thresholds but again, mean differences at each frequency were small and likely imperceptible. These findings support the possibility that valid hearing testing can take place outside of a clinical booth using portable systems like that from TympaHealth, opening up the possibility of testing hearing and fitting hearing aids through pharmacies, opticians, and in care homes.

A genome-wide association study reveals a polygenic architecture of speech-in-noise deficits in individuals with self-reported normal hearing

Speech-in-noise (SIN) perception is a primary complaint of individuals with audiometric hearing loss. SIN performance varies drastically, even among individuals with normal hearing. The present genome-wide association study (GWAS) investigated the genetic basis of SIN deficits in individuals with self-reported normal hearing in quiet situations. GWAS was performed on 279,911 individuals from the UB Biobank cohort, with 58,847 reporting SIN deficits despite reporting normal hearing in quiet. GWAS identified 996 single nucleotide polymorphisms (SNPs), achieving significance (p < 5*10−8) across four genomic loci. 720 SNPs across 21 loci achieved suggestive significance (p < 10−6). GWAS signals were enriched in brain tissues, such as the anterior cingulate cortex, dorsolateral prefrontal cortex, entorhinal cortex, frontal cortex, hippocampus, and inferior temporal cortex. Cochlear cell types revealed no significant association with SIN deficits. SIN deficits were associated with various health traits, including neuropsychiatric, sensory, cognitive, metabolic, cardiovascular, and inflammatory conditions. A replication analysis was conducted on 242 healthy young adults. Self-reported speech perception, hearing thresholds (0.25–16 kHz), and distortion product otoacoustic emissions (1–16 kHz) were utilized for the replication analysis. 73 SNPs were replicated with a self-reported speech perception measure. 211 SNPs were replicated with at least one and 66 with at least two audiological measures. 12 SNPs near or within MAPT, GRM3, and HLA-DQA1 were replicated for all audiological measures. The present study highlighted a polygenic architecture underlying SIN deficits in individuals with self-reported normal hearing.

Analysis of one-year outcomes after cochlear implantation in adults with single-sided deafness

Objectives: To investigate the outcomes of cochlear implantation in Mandarin-speaking cochlear implant (CI) users with single-sided deafness (SSD). Methods: This study was a single-center prospective cohort study. Eleven Mandarin-speaking adult SSD patients who underwent CI implantation at Capital Medical University Beijing Tongren Hospital from August 2020 to October 2021 were recruited, including 6 males and 5 females, with the age ranging from 24 to 50 years old. In a sound field with 7 loudspeakers distributed at 180°, we measured root-mean-square error(RMSE)in SSD patients at the preoperative, 1-month, 3-month, 6-month, and 12-month after switch-on to assess the improvement of sound source localization. The Mandarin Speech Perception (MSP) was used in the sound field to test the speech reception threshold (SRT) of SSD patients under different signal-to-noise locations in a steady-state noise under conditions of CI off and CI on, to reflect the head shadow effect(SSSDNNH), binaural summation effect(S0N0) and squelch effect(S0NSSD). The Tinnitus Handicap Inventory (THI) and the Visual Analogue Scale (VAS) were used to assess changes in tinnitus severity and tinnitus loudness in SSD patients at each time point. The Speech, Spatial and Qualities of Hearing Scale(SSQ) and the Nijmegen Cochlear Implantation Scale (NCIQ) were used to assess the subjective benefits of spatial speech perception and quality of life in SSD patients after cochlear implantation. SPSS 19.0 software was used for statistical analysis. Results: SSD patients showed a significant improvement in the poorer ear in hearing thresholds with CI-on compared with CI-off; The ability to localize the sound source was significantly improved, with statistically significant differences in RMSE at each follow-up time compared with the preoperative period (P<0.05). In the SSSDNNH condition, which reflects the head shadow effect, the SRT in binaural hearing was significantly improved by 6.5 dB compared with unaided condition, and the difference was statistically significant (t=6.25, P=0.001). However, there was no significant improvement in SRT between the binaural hearing condition and unaided conditions in the S0N0 and S0NSSD conditions (P>0.05). The total score of THI and three dimensions were significant decreased (P<0.05). Tinnitus VAS scores were significantly lower in binaural hearing compared to the unaided condition (P<0.001). The total score of SSQ, and the scores of speech and spatial dimensions were significant improved in binaural hearing compared to the unaided condition (P<0.001). There was no statistical difference in NCIQ questionnaire scores between preoperative and postoperative (P>0.05), and only the self-efficacy subscore showed a significant increase(Z=-2.497,P=0.013). Conclusion: CI could help Mandarin-speaking SSD patients restore binaural hearing to some extent, improve sound localization and speech recognition in noise. In addition, CI in SSD patients could suppress tinnitus, reduce the loudness of tinnitus, and improve subjective perceptions of spatial hearing and quality of life.

Correlation between hearing loss and mild cognitive impairment in the elderly population: Mendelian randomization and cross-sectional study.

Hearing loss and tinnitus have been linked to mild cognitive impairment (MCI); however, the evidence is constrained by ethical and temporal constraints, and few prospective studies have definitively established causation. This study aims to utilize Mendelian randomization (MR) and cross-sectional studies to validate and analyze this association. This study employs a two-step approach. Initially, the genetic data of the European population from the Genome-wide association studies (GWAS) database is utilized to establish the causal relationship between hearing loss and cognitive impairment through Mendelian randomization using the inverse variance weighted (IVW) method. This is achieved by identifying strongly correlated single nucleotide polymorphisms (SNPs), eliminating linkage disequilibrium, and excluding weak instrumental variables. In the second step, 363 elderly individuals from 10 communities in Qingdao, China are assessed and examined using methods questionnaire survey and pure tone audiology (PTA). Logistic regression and multiple linear regression were used to analyze the risk factors of MCI in the elderly and to calculate the cutoff values. Mendelian randomization studies have shown that hearing loss is a risk factor for MCI in European populations, with a risk ratio of hearing loss to MCI loss of 1. 23. The findings of this cross-sectional study indicate that age, tinnitus, and hearing loss emerged as significant risk factors for MCI in univariate logistic regression analysis. Furthermore, multivariate logistic regression analysis identified hearing loss and tinnitus as potential risk factors for MCI. Consistent results were observed in multiple linear regression analysis, revealing that hearing loss and age significantly influenced the development of MCI. Additionally, a notable finding was that the likelihood of MCI occurrence increased by 9% when the hearing threshold exceeded 20 decibels. This study provides evidence from genomic and epidemiological investigations indicating that hearing loss may serve as a risk factor for cognitive impairment. While our epidemiological study has found both hearing loss and tinnitus as potential risk factors for cognitive decline, additional research is required to establish a causal relationship, particularly given that tinnitus can manifest as a symptom of various underlying medical conditions.

Insertion trauma of a novel inner ear catheter for intracochlear drug delivery.

Even with recent research advances, effective delivery of a compound to its target cells inside the inner ear remains a challenging endeavor due to anatomical and physiological barriers. Direct intracochlear drug administration with an inner ear catheter (IEC) aims to overcome this obstacle and strives to provide a safe and efficient way for inner ear pharmacotherapy. The goal of this study was to histologically and audiologically evaluate the traumatic properties of a novel IEC for intracochlear drug delivery in a large animal model. Seven inner ears of piglets that had undergone intracochlear fluorescein isothiocyanate dextran application via an IEC (n = 4) or round window membrane (RWM) puncture with a needle (n = 3) followed by sequential apical perilymph sampling were histologically analyzed. Additionally, obtained objective auditory compound action potential and cochlear microphonic measurements were compared. Cochlear cryosections were stained using hematoxylin and eosin, and preservation of inner ear structures was investigated. Moreover, one cochlea was methylmethacrylate-embedded and analyzed with the IEC in situ. Histological evaluation revealed an atraumatic insertion and subsequent compound application in a majority of IEC-inserted inner ears. Click cochlear compound action potential (CAP) shifts in the IEC groups reached a maximum of 5 dB (1.25 ± 2.5 dB) post administration and prior to perilymph sampling. In comparison, application by RWM puncture generated a maximum click CAP hearing threshold shift of 50 dB (23.3 ± 23.1 dB) coinciding with coagulated blood in the basal cochlear turn in one specimen of the latter group. Furthermore, in situ histology showed an atraumatic insertion of the IEC demonstrating preserved intracochlear structures. The IEC appears to be a promising and efficient way for inner ear drug delivery. The similarities between the porcine and human inner ear enhance the clinical translation of our findings and increase confidence regarding the safe applicability of the IEC in human subjects.