OBJECTIVE: To identify the pathophysiological definitions adopted by studies investigating \"cochlear synaptopathy\" (CS) and \"hidden hearing loss\" (HHL).
METHODS: The combination of keywords \"Auditory Synaptopathy\" or \"Neuronal Synaptopathy\" or \"Hidden Hearing Loss\" with \"etiology\" or \"causality\" or \"diagnosis\" was used in the databases EMBASE, Pubmed (MEDLINE), CINAHL (EBSCO), and Web of Science.
METHODS: Studies that investigated CS or HHL in humans using behavioral and/or electrophysiological procedures were included.
METHODS: Data analysis and extraction were performed with regard to terminology, definitions, and population.
RESULTS: 49 articles were included. Of these, 61.2% used the CS terminology, 34.7% used both terms, and 4.1% used HHL. The most-studied conditions were exposure to noise and tinnitus.
CONCLUSIONS: CS terminology was used in most studies, referring to the pathophysiological process of deafferentiation between the cochlear nerve fibers and inner hair cells.
OBJECTIVE: Identificar as definições fisiopatológicas adotadas pelos estudos que investigaram a “sinaptopatia coclear” (SC) e “perda auditiva oculta” (PAO).
UNASSIGNED: Utilizou-se a combinação de unitermos “Auditory Synaptopathy” or “Neuronal Synaptopathy” or “Hidden Hearing Loss” com “etiology” or “causality” or “diagnosis” nas bases de dados EMBASE, Pubmed (MEDLINE), CINAHL (EBSCO) e Web of Science.
UNASSIGNED: Incluiu-se estudos que investigaram a SC ou PAO em humanos com procedimentos comportamentais e/ou eletrofisiológicos.
UNASSIGNED: Realizou-se a análise e extração de dados quanto a terminologia, definição e população estudada.
RESULTS: Foram incluídos 49 artigos. Destes, 61,2% utilizaram a terminologia SC, 34,7% ambos os termos e 4,1% utilizaram PAO. As condições mais estudadas foram exposição ao ruído e zumbido.
UNASSIGNED: A terminologia SC foi empregada na maioria dos estudos, com referência ao processo fisiopatológico de desaferenciação entre as fibras do nervo coclear e as células ciliadas internas.

OBJECTIVE: Technological advancements in mobile audiometry (MA) have enabled hearing assessment using tablets and smartphones. This systematic review (PROSPERO ID: CRD42021274761) aimed to identify MA options available to health providers, assess their accuracy in measuring hearing thresholds, and explore factors that might influence their accuracy.
METHODS: A systematic search of online databases including PubMed, Embase, Cochrane, Evidence Search and Dynamed was conducted on 13th December 2021, and repeated on 30th October 2022, using appropriate Medical Subject Headings (MeSH) terms. Eligible studies reported the use of MA to determine hearing thresholds and compared results to conventional pure-tone audiometry (CA). Studies investigating MA for hearing screening (i.e. reporting just pass/fail) were ineligible for inclusion. Two authors independently reviewed studies, extracted data, and assessed methodological quality and risk of bias using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.
METHODS: Adults and children, with and without diagnosis of hearing impairment.
METHODS: A meta-analysis was performed to obtain the mean difference between thresholds measured using MA and CA in dB HL.
RESULTS: Searches returned 858 articles. After systematic review, 17 articles including 1032 participants were analysed. The most used software application was ShoeboxTM (6/17) followed by Hearing TestTM (3/17), then HearTestTM (2/17). Tablet computers were used in ten studies, smartphones in six, and a computer in one. The mean difference between MA and CA thresholds was 1.36 dB (95% CI, 0.07-2.66, p = 0.04). Significant differences between mobile audiometry (MA) and conventional audiometry (CA) thresholds were observed in thresholds measured at 500Hz, in children, when MA was conducted in a sound booth, and when MA was self-administered. However, these differences did not exceed the clinically significant threshold of 10 decibels (dB). Included studies exhibited high levels of heterogeneity, high risk of bias and low concerns about applicability.
CONCLUSIONS: MA compares favourably to CA in measuring hearing thresholds and has role in providing access to hearing assessment in situations where CA is not available or feasible. Future studies should prioritize the integration of pure-tone threshold assessment with additional tests, such as Speech Recognition and Digits-in-Noise, for a more rounded evaluation of hearing ability, assesses acceptability and feasibility, and the cost-effectiveness of MA in non-specialist settings.

Current evidence supports the growing application of extended high-frequency (EHF: 9 to 20 kHz) audiometry in hearing research, which likely results from the high vulnerability of this frequency region to damage induced by known auditory risk factors. The present systematic review and meta-analysis were performed to investigate whether adults with a normal audiogram and tinnitus show increased EHF hearing thresholds relative to control peers.
A comprehensive search was undertaken on electronic databases consisting of PubMed, ScienceDirect, Wiley, and Google Scholar using combined keywords: \"tinnitus,\" \"extended high frequency,\" \"normal audiogram,\" and \"hidden hearing loss.\"
From 261 articles found by searching databases, nine studies met the inclusion criteria for the meta-analysis. A significant difference was observed between tinnitus and control groups in the effect size analysis of hearing thresholds at 10, 12.5, 14, 16, and 18 kHz ( p ≤ 0.001), and the I-square heterogeneity analysis was below 50% in all studies ( p ≥ 0.131). Visual inspection by the Funnel plot and Egger\'s regression test ( p ≥ 0.211) also exhibited no publication bias in the meta-analyses.
Our findings are in support of the idea that in most cases, tinnitus is associated with some degree of cochlear mechanical dysfunction, which may not be detected by conventional audiometry alone. This finding underscores the significance of EHF audiometry in clinical practice, which may help both early identification of individuals susceptible to developing tinnitus and reduce the number of new cases through preventive counseling programs.

The auditory system is particularly vulnerable to blast injury due to the ear\'s role as a highly sensitive pressure transducer. Over the past several decades, studies have used a variety of animal models and experimental procedures to recreate blast-induced acoustic trauma. Given the developing nature of this field and our incomplete understanding of molecular mechanisms underlying blast-related auditory disturbances, an updated discussion about these studies is warranted. Here, we comprehensively review well-established blast-related auditory pathology including tympanic membrane perforation and hair cell loss. In addition, we discuss important mechanistic studies that aim to bridge gaps in our current understanding of the molecular and microstructural events underlying blast-induced cochlear, auditory nerve, brainstem, and central auditory system damage. Key findings from the recent literature include the association between endolymphatic hydrops and cochlear synaptic loss, blast-induced neuroinflammatory markers in the peripheral and central auditory system, and therapeutic approaches targeting biochemical markers of blast injury. We conclude that blast is an extreme form of noise exposure. Blast waves produce cochlear damage that appears similar to, but more extreme than, the standard noise exposure protocols used in auditory research. However, experimental variations in studies of blast-induced acoustic trauma make it challenging to compare and interpret data across studies.

The present study explores the scientific evidence on whether music exposure temporarily or permanently affects hearing sensitivity in young adults. Six electronic databases were searched using related keywords for the four categories of personal listening devices, listening habits, hearing outcomes, and age. The Hedges\' g and its 95% confidence intervals (CIs) were estimated. A Higgins I2 was also used to check for heterogeneity. To test for publication bias, funnel plots were drawn using Egger\'s regression. Based on the inclusion criteria, 16 studies were divided into two groups to identify short-term hearing changes (n = 7) and long-term hearing changes (n = 9). In the short term, there was no significant immediate change in the thresholds or amplitudes after the music exposure, although pure-tone thresholds (PTAs) and distortion product otoacoustic emissions (DPOAEs) did show the highest effect size (-0.344, CI -0.727 to 0.038) and (0.124, CI -0.047 to 0.296) at 4 kHz. On the other hand, for long-term hearing changes, the PTA provided the highest effect size at 6 kHz (-0.525, CI -0.897 to -0.154) and 8 kHz (-0.486, CI -0.819 to -0.152), while also implying that habitual and repeated personal listening device (PLD) usage can act on some significant hearing changes in audiological tests. We conclude that the use of a PLD produces a few temporary hearing changes at 4 kHz after its use but that the changes are then reversed. However, it is important to note heavy PLD users\' experience regarding permanent changes in their hearing thresholds at high frequencies, and the public should be educated on this issue.

It is well-established that excessive noise exposure can systematically shift audiometric thresholds (i.e., noise-induced hearing loss, NIHL) making sounds at the lower end of the dynamic range difficult to detect. An often overlooked symptom of NIHL is the degraded ability to resolve temporal fluctuations in supra-threshold signals. Given that the temporal properties of speech are highly dynamic, it is not surprising that NIHL greatly reduces one\'s ability to clearly decipher spoken language. However, systematic characterization of noise-induced impairments on supra-threshold signals in humans is difficult given the variability in noise exposure among individuals. Fortunately, the chinchilla is audiometrically similar to humans, making it an ideal animal model to investigate noise-induced supra-threshold deficits. Through a series of studies using the chinchilla, the authors have elucidated several noise-induced deficits in temporal processing that occur at supra-threshold levels. These experiments highlight the importance of the chinchilla model in developing an understanding of noise-induced deficits in temporal processing.

To conduct systematic review and meta-analyses of preclinical studies describing the efficacy of glucocorticoids administered via different routes for hearing preservation after cochlear implantation.
A literature search was performed in PubMed to identify peer-reviewed articles published before December 31, 2017, with no language restrictions. Search components were \"Cochlear implant,\" \"Glucocorticoids,\" and \"Hearing preservation.\" The results were specified for animal studies.
Original studies in which glucocorticoids were administered before or during cochlear implantation in animal models and hearing threshold shifts were measured using auditory brainstem response.
Quality of included studies was assessed using the SYstematic Review Centre for Laboratory animal Experimentation protocol. Threshold Shift reduction between the \"study\" and \"control\" groups at 1-month postimplantation was the parameter used to evaluate hearing preservation.
The random-effects models were used to combine the results of selected studies. Separate meta-analyses were performed for drug-eluting electrodes, systemic, and local administration.
Administering either systemic or topical glucocorticosteroids had a significant effect on preserving low and high-frequency hearing. Topical administration was equally effective across a range of concentration levels and provided maximal hearing preservation when applied 120 minutes before implantation. The effect of systemic treatment was achieved with high doses, equivalent to 26 mg of dexamethasone per day in humans. No significant effect was found with the use of drug-eluting electrodes and more studies are needed to characterise the utility and efficacy of this administration method.

It is estimated that over 60% of adults with dementia will also have a hearing impairment, resulting in a dual sensory-cognitive communication disability. Hearing interventions may lessen the impact of hearing impairment on a communication disability; yet, for audiologists to recommend appropriate hearing interventions, the individual\'s hearing thresholds must first be accurately established. The gold standard test for establishing hearing thresholds is pure-tone audiometry (PTA). However, the ability of adults with dementia to successfully complete PTA is uncertain. This systematic review examined studies of adults with dementia to better determine the proportion who could complete PTA.
Systematic review.
Studies were included that assessed hearing in older adults who were reported as having mild and greater dementia. From a total of 1,237 eligible studies, only three were found to meet all inclusion criteria.
Across these three studies, the proportion of adults with dementia who could successfully complete PTA ranged from 56% to 59%.
Further research is needed in this area, particularly for adults with moderate and severe stages of dementia. Future research should also consider the feasibility of complementary, non-behavioural hearing tests. This systematic review was registered with the PROSPERO database, registration number CRD42017073041.

OBJECTIVE: COPD is an irreversible or persistent airflow obstruction, which affects up to 600 million people globally. The primary purpose of this systematic review was to explore the COPD-based alteration in the auditory system function by conducting a quantitative analysis of presently published data.
METHODS: We systematically searched seven diverse electronic databases and manual searching of references to identify relevant studies. Data from the selected studies were rated by two investigators independently in a blinded fashion. Meta-analysis was done on pooled data using Cochrane\'s Review Manager 5.3.
RESULTS: Sixteen articles received suitable scores and were thus included for further processes. Hearing loss (HL) was defined as a change in pure tone audiometry (PTA) thresholds, auditory brainstem response (ABR), and auditory P300 parameters. ABR wave was significantly elongated in patients with COPD than in controls (standardized mean difference [SMD]=0.27, 95% CI: 0.05-0.48, P=0.02). PTA was significantly higher in patients with COPD when compared with controls (SMD=1.76, 95% CI: 0.43-3.08, P=0.0004). We found that patients with COPD had a significantly higher latency than controls (SMD=1.30, 95% CI: 0.79-1.80, P=0.0001).
CONCLUSIONS: COPD patients had considerably greater incidence of HL when compared with controls. Interestingly, although the mean PTA thresholds at every frequency for COPD patients were higher than those for controls, these values were still in the slight to mild HL ranges. Prolonged ABR wave latencies in the COPD patients suggest retro-cochlear involvement. Thus, COPD most frequently clusters with HL, but it is worth noting that alteration in hearing is not always recognized by medical experts as a frequent comorbidity associated with COPD.

This review considers the nature of the sound generated by wind turbines focusing on the low-frequency sound (LF) and infrasound (IS) to understand the usefulness of the sound measures where people work and sleep. A second focus concerns the evidence for mechanisms of physiological transduction of LF/IS or the evidence for somatic effects of LF/IS. While the current evidence does not conclusively demonstrate transduction, it does present a strong prima facia case. There are substantial outstanding questions relating to the measurement and propagation of LF and IS and its encoding by the central nervous system relevant to possible perceptual and physiological effects. A range of possible research areas are identified.