Auditory Nerve Research Articles

A Systematic Review and Meta-analysis Examining Outcomes of Cochlear Implantation in Children With Bilateral Cochlear Nerve Deficiency.

To assess hearing and speech outcomes in pediatric patients with bilateral cochlear nerve deficiency (CND) who underwent cochlear implantation (CI) and to identify factors associated with improved outcomes. PubMed, Embase, Web of Science, and Cochran databases were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that reported hearing and speech outcomes of pediatric patients with bilateral CND who underwent CI were included. Demographics, comorbidities, inner ear abnormalities, CND classification (aplasia or hypoplasia), details of diagnostic workup, and outcomes data were extracted. Outcomes were assessed using the four-level auditory performance level (APL) scale. Meta-analysis, using Cochran-Armitage tests, was performed on patients with individual data to assess factors associated with performance. A total of 314 papers were screened, and 40 papers with 378 total patients met inclusion criteria. A total of 339 patients had patient-level data and were included in the meta-analysis. Of the 339 patients, 19% (n = 63) of patients had no measurable stimulation, 28% (n = 95) had improved detection, 22% (n = 76) achieved closed-set speech perception, and 31% (n = 105) achieved open-set speech perception. Patients with cochlear nerve aplasia (p = 0.016) and syndromes (p < 0.001) had significantly worse APL scores relative to patients with cochlear nerve hypoplasia and patients without syndromes, respectively. While most patients with bilateral CND benefit from CI and almost one-third of patients achieved open-set speech perception, outcomes were heterogenous and one-fifth of patients did not experience measurable benefit from CI.

Artificial Intelligence in CT Diagnosis: Current Status and Future Prospects for Ear Diseases

The human ear, with its complex structures like the ossicular chain, cochlea, and auditory nerve, plays a crucial role in hearing and balance. Common ear diseases, such as hearing loss, tinnitus, facial paralysis and vertigo, affect the quality of life of millions in China. Computed tomography (CT) has seen significant advancements since its introduction to China in 2000. The resolution improves from millimeter to sub-millimeter levels, and further, to 10 μm through bone-dedicated CT technology. The advancements have made CT the preferred method for diagnosing various ear conditions, including congenital malformations, trauma, inflammation, and neoplasm. Artificial intelligence (AI) has brought significant breakthroughs in CT diagnosis. Automatic segmentation of ear structures has dramatically improved with the advent of ultra-high-resolution computed tomography (U-HRCT). AI-driven measurement tools are enhancing the precision and personalization of surgical planning, while deep learning-based anomaly detection is utilized to address the challenges of detecting diverse ear lesions. Furthermore, AI-driven natural language processing and large language models are revolutionizing the generation of radiology reports, providing accurate and standardized diagnostic information. Despite ongoing challenges, the integration of AI into CT is expected to advance the otological field, leading to more precise and personalized treatment for ear diseases.

Radiotherapy-associated Sensorineural Hearing Loss in Pediatric Oncology Patients.

During the radiotherapeutic treatment of pediatric oncology patients, they would be at a latent risk of developing ionizing radiation-induced ototoxicity when the cochlea or auditory nerve is located within the radiation field. Sensorineural hearing loss (SNHL) is an irreversible late complication of radiotherapy, and its incidence depends on various factors such as the patient's hearing sensitivity, total radiation dose to the cochlea, radiotherapy fractionation regimen, age and chemoradiation. Importantly, this complication exhibits serious challenges to adult survivors of childhood cancer, as it has been linked to impairments in academic achievement, psychosocial development, independent living skills, and employment in the survivor population. Therefore, early detection and proper management can alleviate academic, speech, language, social, and psychological morbidity arising from hearing deficits. In the present review, we have addressed issues such as underlying mechanisms of radiation-induced SNHL, audiometric findings of pediatric cancer patients treated with radiotherapy, and management and protection measures against radiation-induced ototoxicity.

Photobiomodulation as a Potential Adjuvant Therapy to Improve Cochlear Implant Efficiency.

Objective: Photobiomodulation (PBM) is a noninvasive therapeutic modality with widespread applications for modulating various biological processes. Although the exact mechanisms of action remain uncertain, PBM promotes homeostasis through diverse pathways, including reducing inflammation and enhancing tissue recovery. Hearing loss is irreversible in mammals due to the limited regenerative capacity of cochlear hair cells. Cochlear implants offer a solution by electrically stimulating the auditory nerve, bypassing damaged hair cells in individuals with severe hearing loss. However, postoperative inflammatory responses and cochlear nerve fiber damage can compromise implant efficacy. Materials and Methods: We investigated current strategies to minimize secondary cochlear damage after cochlear implantation and evaluated the potential of PBM as an adjuvant therapeutic approach. Results: The auditory cell protective effects of PBM could significantly enhance the performance of EAS devices in individuals with residual hearing. Further, postoperative CI is accompanied by an inflammatory response characterized by the upregulation of specific cytokines. Conclusion: Considering the neuroregenerative potential of PBM, its application as a neuroprotective strategy warrants further validation.

Cochlear Synaptopathy Evaluation With Electrocochleography in Patients With Hearing Difficulty in Noise Despite Normal Hearing Levels.

This study examined patients with normal hearing thresholds who had trouble understanding speech in noise. We used electrocochleography (ECochG) to detect and compare SP/AP amplitude area ratios, a potential indicator of cochlear synaptopathy, and investigate speech perception disorder in noise. The study included 68 people aged between 18 and 65 years, 35 patients and 33 healthy volunteers, who applied to the otorhinolaryngology clinic between November 2023 and March 2024 with a 2-month history of difficulty understanding speech in noisy environments. Everyone was given a tiptrode electrode ECochG test, and the results were compared between groups. An ECochG test was recorded with tiptrode electrodes and was performed on all participants, and the results were compared between groups. In the ECochG test, the summation potential/action potential (SP/AP) amplitude and area ratios of patients who had difficulty understanding speech in a noisy environment were statistically higher than those of the control group. ECochG testing may provide additional evidence to evaluate auditory nerve pathways.

Objective Determination of Site-of-Lesion in Auditory Neuropathy.

Auditory neuropathy (AN), a complex hearing disorder, presents challenges in diagnosis and management due to limitations of current diagnostic assessment. This study aims to determine whether diffusion-weighted magnetic resonance imaging (MRI) can be used to identify the site and severity of lesions in individuals with AN. This case-control study included 10 individuals with AN of different etiologies, 7 individuals with neurofibromatosis type 1 (NF1), 5 individuals with cochlear hearing loss, and 37 control participants. Participants were recruited through the University of Melbourne's Neuroaudiology Clinic and the Murdoch Children's Research Institute specialist outpatient clinics. Diffusion-weighted MRI data were collected for all participants and the auditory pathways were evaluated using the fixel-based analysis metric of apparent fiber density. Data on each participant's auditory function were also collected including hearing thresholds, otoacoustic emissions, auditory evoked potentials, and speech-in-noise perceptual ability. Analysis of diffusion-weighted MRI showed abnormal white matter fiber density in distinct locations within the auditory system depending on etiology. Compared with controls, individuals with AN due to perinatal oxygen deprivation showed no white matter abnormalities ( p > 0.05), those with a neurodegenerative conditions known/predicted to cause VIII cranial nerve axonopathy showed significantly lower white matter fiber density in the vestibulocochlear nerve ( p < 0.001), while participants with NF1 showed lower white matter fiber density in the auditory brainstem tracts ( p = 0.003). In addition, auditory behavioral measures of speech perception in noise and gap detection were correlated with fiber density results of the VIII nerve. Diffusion-weighted MRI reveals different patterns of anatomical abnormality within the auditory system depending on etiology. This technique has the potential to guide management recommendations for individuals with peripheral and central auditory pathway abnormality.

Developmental cochlear defects are involved in early-onset hearing loss in A/J mice.

A/J mice exhibited a severe hearing loss (HL) at juvenile stage. Up-to-date, studies on HL in A/J mice have mostly focused on the damage or dysfunction of hair cells (HCs), spiral ganglion neurons (SGNs), and stereocilia. We examined A/J mice at the early postnatal stage and found that the damage and the loss of outer hair cells (OHCs) are not severe enough to explain the profound HL observed at this age, which suggests that other cochlear defects may be responsible for HL. To better understand the mechanisms of early-onset HLin A/J mice, we characterized the pathology of the cochlea from postnatal day 3 to day 21. Our results showed defects in cochlear HC stereocilia and MET channel function as early as 3 days old. We also found abnormal localization and a significant reduction in the number of ribbon synapses in 2-week-old A/J mice. There are also abnormalities in the cochlear nerve innervation and terminal swellings in 3-week-old A/J mice. All of the abnormalities of cochlear existed in the A/J mice were identified in the juvenile stage and occurred before HCs or auditory nerve loss and was the initial pathological change. Our results suggest that developmental defects and subsequent cochlear degeneration are responsible for early-onset hearing loss in A/J mice.

Models optimized for real-world tasks reveal the task-dependent necessity of precise temporal coding in hearing.

Neurons encode information in the timing of their spikes in addition to their firing rates. Spike timing is particularly precise in the auditory nerve, where action potentials phase lock to sound with sub-millisecond precision, but its behavioral relevance remains uncertain. We optimized machine learning models to perform real-world hearing tasks with simulated cochlear input, assessing the precision of auditory nerve spike timing needed to reproduce human behavior. Models with high-fidelity phase locking exhibited more human-like sound localization and speech perception than models without, consistent with an essential role in human hearing. However, the temporal precision needed to reproduce human-like behavior varied across tasks, as did the precision that benefited real-world task performance. These effects suggest that perceptual domains incorporate phase locking to different extents depending on the demands of real-world hearing. The results illustrate how optimizing models for realistic tasks can clarify the role of candidate neural codes in perception.

A full-custom fully implantable cochlear implant system validated in vivo with an animal model

Realizations of fully implantable cochlear implants (FICIs) for providing adequate solution to esthetic concerns and frequent battery replacement have lacked of addressing system level criteria as a complete device. Here, we present a full-custom FICI that considers design of both an implantable sensor for wide range sound sensing and a signal conditioning circuit for electrical stimulation of the auditory nerve. The microelectromechanical system (MEMS)-based acoustic sensor utilizes multiple cantilever beam structures to sense and filter the mechanical vibrations on the ossicular chain. The area optimized bilayer design of the piezoelectric sensor met with the volume limitation in the middle ear while achieving high signal-to-noise-ratio. The sensor outputs are processed by a current mode low-power signal conditioning circuit that stimulates the auditory neurons through intracochlear electrodes. The FICI is validated with an in vivo model where the electrical auditory brainstem response (eABR) of the animal was observed while applying sound excitation. The eABR results demonstrate that the system is able to evoke responses in the auditory nerves of a guinea pig for sound range of 45–100 dB SPL within the selected frequency bands.

Application and development of super minimally invasive surgery concept in acoustic neuroma resection

With the development of medicine, surgery has also experienced the development and evolution from traditional surgery to minimally invasive surgery, and then to super minimally invasive surgery (SMIS). Meanwhile, reducing surgical trauma and preserving and reconstructing nerve function have gradually become new goals of modern vestibular schwannoma (VS) resection surgery. The surgery of VS can be divided into hearing-preserving surgery (retrosigmoid approach and middle fossa approach) and non-hearing-preserving surgery (traditional translabyrinthine approach), according to whether the patient has practical hearing before operation. Improving the hearing preservation rate of hearing-preserving surgery and reconstructing the hearing of patients with non-hearing-preserving surgery are major challenges and hotspots. The traditional translabyrinthine approach has the highest proportion in the Department of Otolaryngology-Head and Neck Surgery, with the advantages of high facial nerve preservation rate and few intracranial complications. However, due to the resection of the cochlear nerve and labyrinth, the cochlea develops fibrosis, and patients lose the opportunity to reconstruct hearing through cochlear implantation. The new modified translabyrinthine approach can preserve the cochlear nerve and effectively reduce cochlear fibrosis, providing an opportunity for cochlear implantation to reconstruct the hearing. This is another important breakthrough in vestibular schwannoma surgery.

Characterizing Hearing Outcomes Following Treatment of Cerebellopontine Angle Meningiomas

Abstract Objectives To characterize treatment and hearing outcomes for cerebellopontine angle (CPA) meningiomas with inherent risks of hearing loss and identify predictors of hearing loss for surgically treated lesions. Design Retrospective chart review. Setting Tertiary care medical center. Participants Adult patients with CPA meningiomas impinging upon cranial nerve VIII and/or pretreatment hearing loss managed with microsurgery or stereotactic radiosurgery (SRS) with Gamma Knife at our center between 2012 and 2023. Main Outcome Measures Hearing preservation rate was determined from analysis of patients with pretreatment serviceable hearing for whom hearing-preserving treatment was attempted. Surgical patients were further analyzed using multivariable Cox proportional hazards regression models to identify factors predictive of postoperative hearing loss. Results We identified 80 patients with CPA meningiomas meeting inclusion criteria who were managed with either microsurgery (43, 54%) or radiosurgery (37, 46%). Following SRS, hearing was preserved in 88% of cases. Following microsurgery, hearing was preserved in 71% of patients—all patients who lost hearing had tumors involving the internal auditory canal (IAC). Among surgical patients only, multivariable analysis accounting for preoperative hearing, recurrence status, lesion size, and patient age, the preoperative imaging finding that the CPA meningioma surrounded the vestibulocochlear nerve was significantly associated with hearing loss (hazard ratio: 10.3, 95% confidence interval: 1.3–81.4, p = 0.02). Conclusion Most patients with meningiomas of the CPA can experience preservation of hearing, even when there is risk of hearing loss based on pretreatment evaluation. IAC invasion and surrounding of eighth nerve by tumor may portend poorer hearing outcomes in surgically managed patients.

Combined-electrical optogenetic stimulation but not channelrhodopsin kinetics improves the fidelity of high rate stimulation in the auditory pathway in mice

Novel stimulation methods are needed to overcome the limitations of contemporary cochlear implants. Optogenetics is a technique that confers light sensitivity to neurons via the genetic introduction of light-sensitive ion channels. By controlling neural activity with light, auditory neurons can be activated with higher spatial precision. Understanding the behaviour of opsins at high stimulation rates is an important step towards their translation. To elucidate this, we compared the temporal characteristics of auditory nerve and inferior colliculus responses to optogenetic, electrical, and combined optogenetic-electrical stimulation in virally transduced mice expressing one of two channelrhodopsins, ChR2-H134R or ChIEF, at stimulation rates up to 400 pulses per second (pps). At 100 pps, optogenetic responses in ChIEF mice demonstrated higher fidelity, less change in latency, and greater response stability compared to responses in ChR2-H134R mice, but not at higher rates. Combined stimulation improved the response characteristics in both cohorts at 400 pps, although there was no consistent facilitation of electrical responses. Despite these results, day-long stimulation (up to 13 h) led to severe and non-recoverable deterioration of the optogenetic responses. The results of this study have significant implications for the translation of optogenetic-only and combined stimulation techniques for hearing loss.

The Predictive Value of Preoperative Measurements of Cochlear Nerve Diameters From MRT and Postoperative Speech Perception in Adult Patients With Cochlear Implant.

The current study aims to investigate whether objective measurements of the cochlear nerve (CN), derived from preoperative MRI images, correlate with postoperative speech perception in CI patients. Retrospective cohort study. University Medical Center, tertiary academic referral center. Patients undergoing a cochlear implant surgery including MED-EL (Synchrony 2, FLEX electrode series; MED-EL, Innsbruck, Austria) Cochlear (slim straight electrodes; Cochlear Ltd., Sydney, Australia), Advanced Bionics (HiRes Ultra 3D CI, HiFocus SlimJ electrodes; Sonova, Zürich, Switzerland), and Oticon (Neuro Zti EVO; Oticon A/S, Smørum, Denmark) between 2020 and 2023. Preoperative MRI images were utilized to measure the volume of the modiolus (VM), the cross-sectional areas of the CN (ACN), and for normalization, the area of the facial nerve (AFN) and the area of the internal ear canal (AIEC). Postoperative speech perceptions were assessed through word recognition scores (WRS) at several stages following the first fitting (FF) of the CI processor: immediately after FF, 1 month, 3 months, and 6 months after FF. Sixty-eight patients were enrolled in this study. A statistically significant positive correlation between the ratio between ACN and AFN (ACN/AFN) and WRSFF was identified (R = 0.36, p < 0.003). However, this correlation disappeared in subsequent follow-up tests. Moreover, upon grouping patients based on their degree of asymmetrical hearing loss, it was observed that the correlation was primarily driven by patients with moderate to severe asymmetrical hearing loss (AHLm) on the contralateral side (R = 0.62, p = 0.0003). The present results suggest that assessing the size of the CN through MRI has limited predictive utility for postoperative speech perceptions during CI consultations. This limitation seems to be particularly relevant for AHLm patients and is confined to the initial activation period.

Long-Term Follow-Up After Translabyrinthine IAC Tumor Removal With Simultaneous Cochlear Implantation.

To evaluate the long-term hearing outcome after translabyrinthine resection of tumors within the internal auditory canal (IAC) with simultaneous cochlear implantation (CI). Prospective study. Tertiary referral center. Thirty-seven patients with tumors of the IAC undergoing translabyrinthine tumor surgery as a first-line therapy. Intraoperatively, electrically evoked auditory brainstem response audiometry (eABR) was performed in all patients to assess cochlear nerve (CN) integrity. In case of preserved CN function after tumor removal, CI was subsequently performed. Postoperatively, patients were regularly followed up to evaluate pure-tone hearing as well as speech recognition with a monosyllabic word comprehension test. Postoperative hearing thresholds and word recognition scores. Of 37 included patients, 22 (59.46%) had positive eABR responses after tumor removal. Twenty-one of these underwent simultaneous CI directly after tumor surgery and were followed-up for 24.24 ± 19.83 months after surgery. Hearing of these patients significantly improved from 73.87 ± 21.40 dB preoperatively to a mean pure-tone average of 41.56 ± 18.87 dB 1 year (p = 0.0008) and 34.58 ± 2.92 dB 3 years after surgery (p = 0.0157). Speech recognition significantly recovered from 13.33 ± 25.41% to 58.93 ± 27.61% 1 year (p = 0.0012) and 51.67 ± 28.58% 3 years postoperatively (p = 0.0164). Regardless of tumor histopathology, CI is an effective option to restore patients' hearing after translabyrinthine tumor surgery. After CI, patients hearing can be restored over a long-term period of a minimum of 3 years post-surgery. Furthermore, eABR proves to be a practical tool to evaluate CN function and screen for patients eligible for CI.

The Role of Platelet-Rich Plasma in the Management of Sensorineural Hearing Loss: Current Evidence and Emerging Trends.

Sensorineural hearing loss (SNHL) is a common form of hearing impairment characterized by damage to the inner ear or auditory nerve, resulting in significant communication difficulties and reduced quality of life. Current treatment options, including hearing aids, cochlear implants, and corticosteroids, primarily focus on symptom management and do not address the underlying pathophysiological damage. Platelet-rich plasma (PRP), an autologous concentrate rich in platelets and growth factors, has emerged as a potential regenerative therapy due to its ability to promote tissue repair and cellular regeneration. This review provides a comprehensive overview of the role of PRP in the management of SNHL, examining the current evidence from preclinical and clinical studies. We discuss the mechanisms through which PRP may promote auditory tissue regeneration and repair, analyze its efficacy and safety profile, and explore innovative approaches and future directions in its application for SNHL. Despite promising preliminary findings, further research is needed to optimize PRP protocols, establish standardized treatment guidelines, and conduct large-scale randomized controlled trials to validate efficacy. This review aims to highlight the potential of PRP as a novel therapeutic strategy in treating SNHL and its possible integration into current clinical practices, offering new hope for patients with this debilitating condition.

Vestibular paroxysmia caused by a subarcuate artery: illustrative case.

Vestibular paroxysmia is defined by spontaneous, recurrent, short, paroxysmal episodes of vertigo. The authors present a case of vestibular paroxysmia caused by neurovascular compression of the vestibulocochlear nerve due to the subarcuate artery, which was successfully treated with microvascular decompression. A 46-year-old man first experienced vertigo attacks 5 years earlier. The attacks became more frequent, and left-sided tinnitus developed over the past 4 months, prompting a referral to our hospital. Carbamazepine treatment alleviated symptoms but had to be discontinued due to rash. Brain magnetic resonance imaging and angiography revealed that the left anterior inferior cerebellar artery was pressing on the cisternal segment of the left vestibulocochlear nerve. The authors diagnosed vestibular paroxysmia caused by neurovascular compression and performed microvascular decompression. During the operation, a subarcuate artery was identified as the offending vessel, with a prominent indentation on the vestibulocochlear nerve. The vertigo was completely relieved following surgery. Neurovascular compression of the vestibulocochlear nerve by the subarcuate artery can result in vestibular paroxysmia. https://thejns.org/doi/abs/10.3171/CASE24239.

A postmortem high-resolution MRI study of the development of cochlear nerve-related structures in the second and third trimesters of pregnancy.

Magnetic resonance imaging (MRI) is used to determine whether cochlear nerve development is normal in infants and adults, but it has not yet been used to evaluate cochlear nerve development or measure cochlear nerve-related structures in the fetus. This study sought to provide imaging data for clinical evaluations concerning cochlear nerve development in the fetus using MRI. Postmortem 3.0-Tesla MRI of inner ear was performed in 51 fetuses with normal temporal bones at 25 to 40 weeks of gestation. The continuous scanning protocol incorporated axial three-dimensional (3D) sampling perfection with application-specific contrasts using different flip angle evolution sequences. The images were evaluated to measure the structures of the cochlear aperture (CA), internal auditory canal (IAC), and vestibulocochlear and facial nerves in the cerebellopontine angle (CPA), which have been reported to be associated with cochlear nerve development. We also calculated the ratio between the diameters of the vestibulocochlear and facial nerves. The measurable parameters were compared between the right and left sides. The threshold for statistical significance was set at P<0.05. The inner ear anatomy was discernible on MRI in all the fetal specimens, and growth of the CA, IAC, vestibulocochlear nerve, and facial nerve in the CPA was observed as fetal age increased. There was no significant difference in the measurements of these structures between the right and left sides (all P>0.05). MRI can be used to help evaluate the anatomy and development of the cochlear nerve in the fetus. These normative measurements could be valuable for clinical evaluations of the cochlear nerve.

Rehabilitation with cochlear implants in children with malformations of the inner ear

Cochlear implants (CIs) are the treatment of choice for hearing rehabilitation in children with congenital or acquired profound hearing loss or deafness in order to ensure appropriate speech development and avoid social deprivation. However, in the case of aradiologically detectable malformation of the inner ear structures and potentially associated hypo- or aplasia of the vestibulocochlear nerve, application of aCI is either not possible, or the functional outcome may be of limited predictability. In addition, the risk of surgical complications is also increased in these patients. Counseling parents and developing an appropriate individual therapeutic decision can therefore be amajor challenge for the medical team. The current paper is intended to provide support in this regard. It presents criteria for various inner ear malformations and discusses possible treatment options.

Calcitriol alleviates noise-induced hearing loss by regulating the ATF3/DUSP1 signalling pathway

BackgroundCalcitriol (Cal) is the most active metabolite of vitamin D and has antioxidant and anti-inflammatory properties. The aim of this study was to investigate the role of Cal in noise-induced hearing loss (NIHL) to further elucidate the mechanism of noise-induced oxidative stress in the mouse cochlea. MethodsC57BL/6 J mice were given six intraperitoneal injections of Cal (500 ng/kg/d). After 14 days of noise exposure, auditory brainstem response (ABR) thresholds, and the cochlear outer hair cell loss rate were analysed to evaluate auditory function. Real-time fluorescence quantitative PCR, immunofluorescence and western blotting were performed in vitro after the treatment of cochlear explants with 100 µM tert-butyl hydroperoxide (TBHP) for 2.5 h and HEI-OC1 cells with 250 µM TBHP for 1.5 h. ResultsIn vivo experiments confirmed that Cal pretreatment mitigated NIHL and outer hair cell death. The in vitro results demonstrated that Cal significantly reduced TBHP-induced cochlear auditory nerve fibre degradation and spiral ganglion neuron damage. Moreover, treatment with Cal inhibited the expression of oxidative stress-related factors (3-NT and 4-HNE) and DNA damage-related factors (γ-H2A.X) and attenuated TBHP-induced apoptosis in cochlear explants and HEI-OC1 cells. A total of 1479 upregulated genes and 1443 downregulated genes were screened in cochlear tissue 1 h after noise exposure. The level of transcription factor 3 (ATF3) was significantly elevated in HEI-OC1 cells after TBHP stimulation. Gene Transcription Regulation Database （GTRD）and Cistrome database analyses revealed that the downstream target gene of ATF3 is dual specificity phosphatase 1 (DUSP1). Cistrome DB Toolkit database results showed that the transcription factor of DUSP1 was ATF3. In addition, the ChIP-PCR results indicated that ATF3 might be a direct transcription factor of DUSP1. ConclusionThe results of our study suggest that Cal attenuates NIHL and inhibits noise-induced apoptosis by regulating the ATF3/DUSP1 signalling pathway.

The relationship and interdependence of auditory thresholds, proposed behavioural measures of hidden hearing loss, and physiological measures of auditory function

Objectives Standard diagnostic measures focus on threshold elevation but hearing concerns may occur independently of threshold elevation – referred to as “hidden hearing loss” (HHL). A deeper understanding of HHL requires measurements that locate dysfunction along the auditory pathway. This study aimed to describe the relationship and interdependence between certain behavioural and physiological measures of auditory function that are thought to be indicative of HHL. Design Data were collected on a battery of behavioural and physiological measures of hearing. Threshold-dependent variance was removed from each measure prior to generating a multiple regression model of the behavioural measures using the physiological measures. Study Sample 224 adults in the United States with audiometric thresholds ≤65 dB HL. Results Thresholds accounted for between 21 and 60% of the variance in our behavioural measures and 5–51% in our physiological measures of hearing. There was no evidence that the behavioural measures of hearing could be predicted by the selected physiological measures. Conclusions Several proposed behavioural measures for HHL: thresholds-in-noise, frequency-modulation detection, and speech recognition in difficult listening conditions, are influenced by hearing sensitivity and are not predicted by outer hair cell or auditory nerve physiology. Therefore, these measures may not be able to assess threshold-independent hearing disorders.