Age-related Sensorineural Hearing Loss Research Articles

Prevalence of Age-Related Sensorineural Hearing Loss and Related Factors in Elderly Patients Attending Tertiary Hospital in Tanzania.

Age-related sensorineural hearing loss (SNHL), is a progressive, usually bilateral hearing loss that occurs in elderly. It is correctable using rehabilitative hearing devices, which can vastly improve the older person's quality of life. This study aimed to find out the prevalence and related factors of age-related sensorineural hearing loss among elderly patients in Tanzania. A total of 380 elderly patients who received Otorhinolaryngology (ORL) services at Muhimbili tertiary hospital were enrolled. Participants were screened for hearing loss and interviewed by the structured questionnaire followed by otoscopic examination and Pure tone Audiometry (PTA). This study included 182(47.9%) males, and 198 (52.1%) females. The prevalence of SNHL was 27.6%, males were mostly affected 57(31.3%) p = 0.574. Bilateral SNHL was found 90 (85.7%) p = 0.026, and the severity of age-related SNHL was found to increase as age increases. Sensorineural hearing loss among the elderly was prevalent, mostly bilateral, and the severity increases with age. Confounding factors such as hypertension, diabetes mellitus (DM), cigarette smoking, and ototoxic medication may have contributed. Elderly should be screened for hearing loss especially on the individuals with other co-morbidities for early diagnosis and management in order to improve the quality of life of the elderly.

Hearing loss in type 1 diabetes mellitus: a need to understand precise pathological mechanisms and develop novel therapeutic approaches

This integrative review and perspective article synthesizes current knowledge about the co-morbidity of Type 1 Diabetes (T1D) and sensorineural hearing loss (SNHL), affecting an estimated 9.2 per 1,000 T1D patients annually. Combining data from clinical, preclinical, and mechanistic studies, the article elucidates the complex pathological mechanisms contributing to SNHL in T1D. It is established that T1D accelerates age-related SNHL and brings about detrimental changes in the auditory system, including damage to outer hair cells (OHCs), inner hair cells (IHCs), the stria vascularis (SV), and the spiral ligament (SL). Furthermore, T1D-associated peripheral neuropathy, microvascular damage, and chronic inflammation in the inner ear contribute to auditory deficits. Although some consistency exists between animal models and human conditions, notable discrepancies warrant the refinement of preclinical models to more accurately mirror human clinical scenarios. This perspective article highlights the need for targeted research to bridge existing knowledge gaps and accelerate the development of early-stage interventions for SNHL in T1D patients. Advancements in this field hold the promise of enhancing clinical prognosis and improving the quality of life of individuals having T1D.

Behavior Change in Chronic Health: Reviewing What We Know, What Is Happening, and What Is Next for Hearing Loss

Untreated age-related sensorineural hearing loss is challenged by low adoption and adherence to hearing aids for treatment. Hearing care has evolved from traditional clinic-controlled treatment to online consumer-centered hearing care, supported by the increasingly person-centered design of hearing aid technology. Greater evidence and a more nuanced understanding of the personal need for adoption versus adherence to the use of consumer hearing care devices are required. Research considering consumer hearing aid acceptance behavior rests on behavior modification theories to guide clinical approaches to increasing hearing aid adoption and adherence. However, in the context of complex chronic health management, there may be a gap in how these theories effectively align with the needs of consumers. Similarly, market data indicates evolving consumer behavior patterns have implications for hearing care theory and implementation, particularly in terms of sustained behavior change. This essay proposes that evidence, including theory and application, be strengthened by revising basic theoretical premises of personal experience with complex chronic health, in addition to considering recent changes in commercial contexts.

Auditory perception in adult hearing aid users with and without auditory training - A comparative study

Background: Individuals with sensorineural hearing loss can regain some lost auditory function with the help of hearing aids, but it may be insufficient under non – optimal condition. Future research aspect lies in processing strategy and training to enhance effects of auditory training and rehabilitation of patients using hearing aids. So research is done to supplement the rehabilitation process with patient centric education, counseling and auditory training to help the listener compensate for loss of auditory signal and improve communication. Whether age-related hearing loss can be decreased by auditory training along with hearing aid is to be researched as it is not clear from previous scientific works whether the outcome is significantly better than those with hearing aid who have not received training. Aims and Objectives: The aim of the study was to determine the role of auditory training for improvement of auditory perception in aged patients with age-related sensorineural hearing loss using binaural hearing aid. Materials and Methods: This prospective observational study was conducted in Otorhinolaryngology department of Burdwan Medical College and Hospital, Burdwan, a rural based tertiary care hospital in Burdwan for 2 months from June 2022 to July 2022 and 50 aged patients with audiologically proven age related sensorineural hearing loss using hearing aid were included in this study after through history taking and meticulous clinical examination after getting institutional ethics committee clearance. Patients were divided in two groups, 25 in experimental group (with auditory training) and 25 in control group (without auditory training) and result was analyzed. Results: Formal auditory training was able to improve the central auditory skills of hearing aid users. Improvement was noted in an objective neurophysiologic correlate and perceived by patients, as revealed in a self-assessment questionnaire. Conclusion: Formal auditory training in adult hearing aid users promotes: Improvement in auditory skills for sound localization, memory for nonverbal sounds in sequence, auditory closure, and figure-to-ground for verbal sounds. Greater benefits with hearing aids in reverberant and noisy environments.

Spatial architecture of the cochlear immune microenvironment in noise-induced and age-related sensorineural hearing loss.

The cochlea encodes sound stimuli and transmits them to the central nervous system, and damage to sensory cells and synapses in the cochlea leads to hearing loss. The inner ear was previously considered to be an immune privileged organ to protect the auditory organ from reactions with the immune system. However, recent studies have revealed the presence of resident macrophages in the cochlea, especially in the spiral ligament, spiral ganglion, and stria vascularis. The tissue-resident macrophages are responsible for the detection, phagocytosis, and clearance of cellular debris and pathogens from the tissues, and they initiate inflammation and influence tissue repair by producing inflammatory cytokines and chemokines. Insult to the cochlea can activate the cochlear macrophages to initiate immune responses. In this review, we describe the distribution and functions of cochlear macrophages in noise-induced hearing impairment and age-related hearing disabilities. We also focus on potential therapeutic interventions concerning hearing loss by modulating local immune responses.

Association of hypertension and age-related sensorineural hearing loss among elderly: A cross-sectional study

Background: Hearing loss (HL) has negative impact on quality of life. The prevalence of HL increases with age. Aims and Objectives: The present study was planned to explore the possible association of hypertension with age-related sensorineural HL (SNHL) in the elderly. Materials and Methods: This was a cross-sectional study done in the ENT Department of Great Eastern Medical School and Hospital, Srikakulam. Consecutive sampling method used. Sample size was considered using the formula – 4pq/l2 and 137 subjects from age group 60–75 years were included in the study. Hypertension was verified through a mercury sphygmomanometer and by a systematized questionnaire about hypertension and the use of medication for blood pressure. The hearing was assessed through threshold audiometric and audiological assessment. The study period: 4 months. All patients from the ENT department in the age group 60–75 years and who gave written informed consent were involved in the study. Participants with a history of ear surgery performed in the past, exposure to loud sounds, recently use of ototoxic drugs, patients with hearing aids, and ear diseases were excluded from the study. Results: Out of 137 subjects 52% had hypertension and 48% had no hypertension. Grade 1 hypertensives suffered from mild HL (7.9%), moderate HL (73%), severe HL (11%), and profound HL (7.9%). In Grade 2, hypertensives suffered from moderate HL (11%), severe HL (33.3%), and profound HL (55.5%). The P-value calculated by the Chi-square method was found to be <0.05 and an odds ratio of more than 1, showing a significant association between hypertension and an increase in HL. Moreover, also a statistically positive correlation of MAP and duration of hypertension with age-related SNHL in both ears. Conclusion: HL in the population under study suggested that hypertension is an accelerating factor of degeneration of the hearing apparatus along with age-related SNHL. Hypertension and ageing were significantly associated with the risk of HL. Patients with hypertension have a greater increase in hearing threshold as compared to those without hypertension.

Building a model to predict the risk of multiple severe neurotoxicities in cancer survivors after cisplatin treatment.

e24066 Background: Cisplatin treatment is used for many cancers, including testicular, ovarian, and head and neck malignancies. Cancer survivors with multiple cisplatin-related toxicities can have poor health-related quality of life (HRQOL). Identification of clinical and genetic factors that predict the risk of these neurotoxicities is critical. Methods: Testicular cancer survivors (TCS) enrolled in the Platinum Study completed surveys, underwent physical examination, extensive audiometric testing, and phlebotomy for genotyping and serum platinum analysis. Cases included TCS with two or more severe toxicities (hearing loss [HL], tinnitus, and peripheral sensory neuropathy [PSN]), defined as follows: hearing threshold > 40dB based on geometric mean of 4-12kHz, responding yes to “Do you have ringing or buzzing in the ears?” and/or EORTC-CIPN20 scores in the severe range for items related to sensory neuropathy. Controls were restricted to TCS without any toxicities. TCS with a single toxicity were excluded from analyses. Penalized logistic regression lasso method was used to create the model to predict the binary outcome. Creatinine clearance and residual serum platinum levels were calculated. Polygenic risk scores (PRS) for traits commonly associated with pharmacokinetics and HL, tinnitus, and PSN were calculated for TCS in the training (n = 284) and validation (n = 157) data sets using PRS publicly available in The Polygenic Score Catalog using PRSice 2.3.3. Models were trained and tested in R 4.1.2. Results: A model to assess the risk of developing multiple severe neurotoxicities that could be used without blood work and additional analysis was developed. Clinical predictors incorporated into the model were age at testicular cancer diagnosis, age at phlebotomy, weight and height. PRS incorporated were age-related sensorineural hearing loss (PGS000762), body fat percentage (PGS002133), creatinine in urine (PGS001944), and peripheral nervous system disease (PGS002039). The accuracy of this model was 77.71%, which was significantly greater than the no information rate (NIR) of 65.61% (p = .00067). The positive and negative predictive values (PPV and NPV) were 72.09% and 79.82%, respectively. The AUC-ROC was 0.804. Adding residual platinum levels and creatinine clearance increased the accuracy of the model to 78.34%, which was significantly greater than the NIR (p = .00035). The PPV was 75.00% and the NPV was 79.49%. The area under the receiver operating characteristic curve (AUC-ROC) was 0.832. Conclusions: TCS are often faced with multiple severe neurotoxicities such as HL, tinnitus, and PSN, which impact HRQOL for many decades. If confirmed, a penalized regression model using clinical and genetic characteristics can predict the risk of developing these phenotypes to guide clinicians in treatment and post-treatment management plans.

Auditory Perceptual Exercises in Adults Adapting to the Use of Hearing Aids.

Older adults with age-related hearing loss often use hearing aids (HAs) to compensate. However, certain challenges in speech perception, especially in noise still exist, despite today’s HA technology. The current study presents an evaluation of a home-based auditory exercises program that can be used during the adaptation process for HA use. The home-based program was developed at a time when telemedicine became prominent in part due to the COVID-19 pandemic. The study included 53 older adults with age-related symmetrical sensorineural hearing loss. They were divided into three groups depending on their experience using HAs. Group 1: Experienced users (participants who used bilateral HAs for at least 2 years). Group 2: New users (participants who were fitted with bilateral HAs for the first time). Group 3: Non-users. These three groups underwent auditory exercises for 3 weeks. The auditory tasks included auditory detection, auditory discrimination, and auditory identification, as well as comprehension with basic (syllables) and more complex (sentences) stimuli, presented in quiet and in noisy listening conditions. All participants completed self-assessment questionnaires before and after the auditory exercises program and underwent a cognitive test at the end. Self-assessed improvements in hearing ability were observed across the HA users groups, with significant changes described by new users. Overall, speech perception in noise was poorer than in quiet. Speech perception accuracy was poorer in the non-users group compared to the users in all tasks. In sessions where stimuli were presented in quiet, similar performance was observed among new and experienced uses. New users performed significantly better than non-users in all speech in noise tasks; however, compared to the experienced users, performance differences depended on task difficulty. The findings indicate that HA users, even new users, had better perceptual performance than their peers who did not receive hearing aids.

Early Health Economic Modeling of Novel Therapeutics in Age-Related Hearing Loss.

BackgroundHealth systems face challenges to accelerate access to innovations that add value and avoid those unlikely to do so. This is very timely to the field of age-related sensorineural hearing loss (ARHL), where a significant unmet market need has been identified and sizeable investments made to promote the development of novel hearing therapeutics (NT). This study aims to apply health economic modeling to inform the development of cost-effective NT.MethodsWe developed a decision-analytic model to assess the potential costs and effects of using regenerative NT in patients ≥50 with ARHL. This was compared to the current standard of care including hearing aids and cochlear implants. Input data was collected from systematic literature searches and expert opinion. A UK NHS healthcare perspective was adopted. Three different but related analyses were performed using probabilistic modeling: (1) headroom analysis, (2) scenario analyses, and (3) threshold analyses.ResultsThe headroom analysis shows an incremental net monetary benefit (iNMB) of £20,017[£11,299–£28,737] compared to the standard of care due to quality-adjusted life-years (QALY) gains and cost savings. Higher therapeutic efficacy and access for patients with all degrees of hearing loss yields higher iNMBs. Threshold analyses shows that the ceiling price of the therapeutic increases with more severe degrees of hearing loss.ConclusionNT for ARHL are potentially cost-effective under current willingness-to-pay (WTP) thresholds with considerable room for improvement in the current standard of care pathway. Our model can be used to help decision makers decide which therapeutics represent value for money and are worth commissioning, thereby paving the way for urgently needed NT.

Cross-modal connectivity effects in age-related hearing loss

Age-related sensorineural hearing loss (HL) leads to localized brain changes in the primary auditory cortex, long-range functional alterations, and is considered a risk factor for dementia. Nonhuman studies have repeatedly highlighted cross-modal brain plasticity in sensorial brain networks other than those primarily involved in the peripheral damage, thus in this study, the possible cortical alterations associated with HL have been analyzed using a whole-brain multimodal connectomic approach.Fifty-two HL and 30 normal hearing participants were examined in a 3T MRI study along with audiological and neurological assessments. Between-regions functional connectivity and whole-brain probabilistic tractography were calculated in a connectome-based manner and graph theory was used to obtain low-dimensional features for the analysis of brain connectivity at global and local levels.The HL condition was associated with a different functional organization of the visual subnetwork as revealed by a significant increase in global efficiency, density, and clustering coefficient. These functional effects were mirrored by similar (but more subtle) structural effects suggesting that a functional repurposing of visual cortical centers occurs to compensate for age-related loss of hearing abilities.

Safety and Efficacy for the Combination of Alpha Lipoic Acid, Gingko Biloba, Vitamin C, Zinc, Magnesium, Vitamin B6, Methylcobalamin, Vitamin E and Chromium Picolinate for the Medical Management of Age Related Hearing Loss: Post Marketing Surveillance Study

Introduction: Age related hearing loss is defined as a bilateral, progressive, symmetrical age-related sensorineural hearing loss, which is most pronounced at the higher frequencies. It is considered that oxidative stress has a central role in the pathology of age-related hearing loss so, this study was conducted to test the efficacy and safety for the combination of antioxidants for the treatment of age-related hearing loss. Methodology: This was a multi-centric study conducted at 11 clinical trial sites. Out of total 176 enrolled, 160 trial subjects completed the study. For efficacy assessment, 2 parameters were used including hearing related quality of life score and score obtained from hearing impairment questionnaire on day 0 (visit 1), 45 (visit 2) and 90 (visit 3). Results: At visit 1, the mean hearing related quality of life score was 4.437 increased to 5.725 at visit 2 and further increased to 6.906 at visit 3. At visit 2 and 3, the increase in hearing related quality of life score was 29.028% and 55.645% respectively as compared to baseline. The score obtained from hearing impairment questionnaire was 25.581 at visit 1 reduced to 16.200 and further reduced to 9.943 at visit 3. Conclusion: The combination of Alpha lipoic acid, Gingko biloba, Vitamin C, Zinc, Magnesium, Vitamin B6, Methyl cobalamin, Vitamin E and Chromium Picolinate can be used for the medical management of age related hearing loss.

Long-Range Auditory Functional Connectivity in Hearing Loss and Rehabilitation.

Background: Patients with age-related sensorineural hearing loss (HL) may benefit from auditory input amplification by using hearing aids (HAs). However, the impact of both HL- and HA-based rehabilitation on central auditory functional connectivity (FC) is not clear. Methodology: Sixty-two HL (22 females, aged 64.4 ± 7.6 years, pure-tone average 50.9 ± 14.7 dB right ear, 50.7 ± 12.9 dB left ear) and 32 normal hearing (NH) subjects (22 females, aged 59.3 ± 7.3 years) were examined in a 3T magnetic resonance imaging (MRI) study. HL patients were analyzed cross-sectionally at baseline (vs. NH subjects) and longitudinally at 6-month follow-up. Between the 2 scans, 31/62 patients used the HA 9.5 ± 3.8 h a day. Arterial spin labeling and blood oxygen level-dependent resting-state functional MRI were performed to measure regional perfusion in the primary auditory cortex and, from here to the whole brain, seed-based FC was performed. Before each scan, HL patients underwent audiological and neurological assessments. Results: At baseline, the HL condition was associated with regional hypoperfusion in right Heschl's gyrus (seed) and negative seed-based FC (anticorrelation) in posterior brain regions. Long-range FC in the precuneus correlated negatively with pure-tone and speech reception average thresholds. At 6-month follow-up, HA usage was associated with seed-based FC increase in the right superior frontal gyrus (SFG) and seed-based FC reduction in the right middle temporal gyrus. Long-range FC changes in the SFG correlated positively with executive function improvements. Conclusions: These findings suggest that HA-based rehabilitation may not reverse HL-related neural effects and yet carry neurological benefits by retuning long-range FC of the auditory system. Impact statement Age-related sensorineural hearing loss (HL) affects 40% to 60% of the worldwide population and a common, viable rehabilitation strategy is to provide auditory input amplification through hearing aids (HAs). By targeting metabolically depressed, auditory cortical centers, our work reveals a possible neural link between peripheral and central vulnerability in HL patients in the form of aberrant, long-range, functional connectivity effects. Similarly, we unveil how wearing HAs for 6 months may induce neuroplastic changes that positively correlate with improved neuropsychological performances.

Adenosine A2B receptor: A pathogenic factor and a therapeutic target for sensorineural hearing loss.

Over 466million people worldwide are diagnosed with hearing loss (HL). About 90% of HL cases are sensorineural HL (SNHL) with treatments limited to hearing aids and cochlear implants with no FDA-approved drugs. Intriguingly, ADA-deficient patients have been reported to have bilateral SNHL, however, its underlying cellular and molecular basis remain unknown. We report that Ada-/- mice, phenocopying ADA-deficient humans, displayed SNHL. Ada-/- mice cochlea with elevated adenosine caused substantial nerve fiber demyelination and mild hair cell loss. ADA enzyme therapy in these mice normalized cochlear adenosine levels, attenuated SNHL, and prevented demyelination. Additionally, ADA enzyme therapy rescued SNHL by restoring nerve fiber structure in Ada-/- mice post two-week drug withdrawal. Moreover, elevated cochlear adenosine in untreated mice was associated with enhanced Adora2b gene expression. Preclinically, ADORA2B-specific antagonist treatment in Ada-/- mice significantly improved HL, nerve fiber density, and myelin compaction. We also provided genetic evidence that ADORA2B is detrimental for age-related SNHL by impairing cochlear myelination in WT aged mice. Overall, understanding purinergic molecular signaling in SNHL in Ada-/- mice allows us to further discover that ADORA2B is also a pathogenic factor underlying aged-related SNHL by impairing cochlear myelination and lowering cochlear adenosine levels or blocking ADORA2B signaling are effective therapies for SNHL.

Early Detection of High-frequency Presbycusis Among Normal Hearing Individuals.

Presbycusis is an age-related sensorineural hearing loss and it may reduce quality of life. We conducted a study to establish the prevalence of high-frequency presbycusis in normal hearing individuals and to validate the role of extended high-frequency distortion product otoacoustic emission (DPOAE) in the screening. A cross-sectional study was conducted among 205 normal hearing adult participants with an age range between 25 and 54 years old. Hearing analysis with extended high-frequency pure-tone audiometry (PTA) and high-frequency DPOAE was carried out for all eligible participants. High-frequency presbycusis was considered to be present when the impairment of more than 25 dB occurs at higher than 8 kHz frequencies on both ears. Prevalence of high-frequency presbycusis using extended PTA was 31.7 (95% CI: 25.3, 38.1) and using high-frequency DPOAE was 57.4 (95% CI: 50.7, 64.4). The sensitivity and specificity of high-frequency DPOAE in detecting high-frequency presbycusis were 72.3 and 49.3% respectively with positive predictive value of 39.8% and negative predictive value of 79.3%. The association between age and high-frequency presbycusis was significant based on high-frequency DPOAE (p = 0.029). The prevalence of high-frequency hearing loss is higher with increasing in age. High-frequency DPOAE may be used as a screening tool followed by confirmation using extended PTA. The early detection of presbycusis is important so that measures can be taken to prevent more severe problems developing.

Effects of Sensorineural Hearing Loss on Cortical Synchronization to Competing Speech during Selective Attention.

When selectively attending to a speech stream in multi-talker scenarios, low-frequency cortical activity is known to synchronize selectively to fluctuations in the attended speech signal. Older listeners with age-related sensorineural hearing loss (presbycusis) often struggle to understand speech in such situations, even when wearing a hearing aid. Yet, it is unclear whether a peripheral hearing loss degrades the attentional modulation of cortical speech tracking. Here, we used psychoacoustics and electroencephalography (EEG) in male and female human listeners to examine potential effects of hearing loss on EEG correlates of speech envelope synchronization in cortex. Behaviorally, older hearing-impaired (HI) listeners showed degraded speech-in-noise recognition and reduced temporal acuity compared with age-matched normal-hearing (NH) controls. During EEG recordings, we used a selective attention task with two spatially separated simultaneous speech streams where NH and HI listeners both showed high speech recognition performance. Low-frequency (<10 Hz) envelope-entrained EEG responses were enhanced in the HI listeners, both for the attended speech, but also for tone sequences modulated at slow rates (4 Hz) during passive listening. Compared with the attended speech, responses to the ignored stream were found to be reduced in both HI and NH listeners, allowing for the attended target to be classified from single-trial EEG data with similar high accuracy in the two groups. However, despite robust attention-modulated speech entrainment, the HI listeners rated the competing speech task to be more difficult. These results suggest that speech-in-noise problems experienced by older HI listeners are not necessarily associated with degraded attentional selection.SIGNIFICANCE STATEMENT People with age-related sensorineural hearing loss often struggle to follow speech in the presence of competing talkers. It is currently unclear whether hearing impairment may impair the ability to use selective attention to suppress distracting speech in situations when the distractor is well segregated from the target. Here, we report amplified envelope-entrained cortical EEG responses to attended speech and to simple tones modulated at speech rates (4 Hz) in listeners with age-related hearing loss. Critically, despite increased self-reported listening difficulties, cortical synchronization to speech mixtures was robustly modulated by selective attention in listeners with hearing loss. This allowed the attended talker to be classified from single-trial EEG responses with high accuracy in both older hearing-impaired listeners and age-matched normal-hearing controls.

The association between age-related sensorineural hearing loss and saccular dysfunction in the elderly

Introduction: Presbycusis or age-related sensorineural hearing loss (ARSNHL) is a complex disorder that results in a slow deterioration in auditory function. A considerable high number of these presbycusis or ARSNHL patients also suffer from dizziness and related vestibular symptoms. Although auditory and vestibular systems are distinct, they work just alike. Hence, there is a great relation among their functions. Once one is stimulated, the other suffers changes as well. Methodology: Participants in this study comprised forty adult patients (60–75 years) divided into two groups: control group with normal hearing and without any vestibular symptoms or diagnosed vestibular diseases and study group with mild-to-moderately severe sensorineural hearing loss with or without dizziness in the form of a sense of imbalance during walking or a sense of rotation of the surrounding, especially on sitting or standing from lying position. All patients in this study were without any history of noise exposure in their life. The audiological status was measured with pure-tone audiometry and auditory brainstem response (ABR). The vestibular system was assessed using videonystagmography test battery and cervical vestibular-evoked myogenic potential (cVEMP). Timed up and go test was used as a quick screening tool for detecting balance problems. ABR and cVEMP results of the groups were calculated and compared. Results: The absolute peak latencies of ABR wave I, III, and V were prolonged in the study group than that in the control group. Vestibular-evoked myogenic potential results showed that P13 and N23 latencies were prolonged and P13–N23 amplitude was decreased in the study group when compared to the control group. Conclusion: Thoughtful examination of the vestibular system, in conjunction with auditory functions in elderly persons, is recommended. This may help discover their subclinical vestibular problem and guide physicians to design a suitable treatment plan that helps in decreasing the risk of falls for aged persons.

ПОРОГОВАЯ И НАДПОРОГОВАЯ МАСКИРОВКА ГРОМКОСТИ ТЕСТОВЫХ ИМПУЛЬСОВ, ВЫЗВАННАЯ ПЕРИОДИЧЕСКОЙ ПОСЛЕДОВАТЕЛЬНОСТЬЮ ИМПУЛЬСОВ

In order to search for indicators of temporal processing of periodic sounds, we studied the effect of the periodicity of a train of masking pulses on the temporal resolution and masking of the loudness of the test pulse, which was the first or the last in the train. Measurements were carried out on listeners with normal hearing and age-related sensorineural hearing loss. The test pulse delay D relative to the train was equal to the pulse repetition period T in the train (D = T). The center frequencies and frequency bands of all pulses were 4 kHz and 240 Hz. Under such conditions, the basis for detecting test pulses was believed to be their loudness. The intensity of masking pulses Im was 80 dB SPL. The period T was varied within the range of 20–150 ms while the test pulse intensity Is within the range of 0–85 dB. The temporal resolution of the pulse loudness was equal to the minimum period Tmin, at which the listener could detect a test pulse. Threshold masking of the test pulse loudness (Is ≪ Im) corresponded to the shift in the test pulse detection threshold, SIО, obtained in the train presence relative to the threshold obtained in silence. If intensities of the masking and test pulses were equal, the latest pulse could not be detected, but the test pulse could be detected by increasing or decreasing its intensity. Thus, supra-threshold masking of the test pulse loudness (Is ∼ Im) was estimated by the shifts, SdIU and SdID, in the threshold intensity decrement and increment of the masked test pulse relative to the threshold intensity increment of a single masking pulse. It was shown that it is only SIO and SdID that were related to the temporal resolution of the test pulses loudness. These shifts depended both on the test pulse position relative to the train and auditory sensitivity of the listeners. The largest SIO and SdID shifts were recorded at the temporal resolution threshold of the test pulse loudness, i.e. at T min. For listeners with normal hearing, Tmin was 25 ms, while SIO and SdID shifts were 12 and 18 dB if the test pulse was ahead of the train and 23 and 0 dB if the test pulse followed the train. In listeners with age-related hearing loss, the Tmin period increased up to 80–150 ms. At T of 120 ms, SIО and SdID shifts were 1 and 4 dB if the test pulse was ahead of the train and 4 and 7 dB if the test pulse followed the train. The informational significance of the Tmin, SIО and SdID indicators was confirmed by their manifestations in the profiles oftest pulse detection threshold dependences on the test pulse delay D (D ≠ T). The Tmin, SIО and SdID indicators could be the characteristics of the temporal perception of periodic sounds, including speech. The causes of threshold and supra-threshold masking of the test pulse loudness at different positions of the test pulse relative to the masking pulse train are discussed.

Identifying Unrecognized Hearing Loss

Identifying Unrecognized Hearing Loss

Effect of Reduced Audibility on Mini-Mental State Examination Scores.

The interaction of audition and cognition has been of interest to researchers and clinicians, especially as the prevalence of hearing loss and cognitive decline increases with advancing age. Cognitive screening tests are commonly used to assess cognitive status in individuals reporting changes in memory or function or to monitor cognitive status over time. These assessments are administered verbally, so performance may be adversely affected by hearing loss. Previous research on the impact of reduced audibility on cognitive screening test scores has been limited to older adults with sensorineural hearing loss (SNHL) or young adults with normal hearing and simulated audibility loss. No comparisons have been conducted to determine whether age-related SNHL and its impact on cognitive screening tests is successfully modeled by audibility reduction. The purpose of this study was to examine the effects of reduced audibility on the Mini-Mental State Examination (MMSE), a common bedside cognitive screening instrument, by comparing performance of cognitively normal older adults with SNHL and young adults with normal hearing. A 1:1 gender-matched case-control design was used for this study. Thirty older adults (60-80 years old) with mild to moderately severe SNHL (cases) and 30 young adults (18-35 years old) with normal hearing (controls) served as participants for this study. Participants in both groups were selected for inclusion if their cognitive status was within normal limits on the Montreal Cognitive Assessment. Case participants were administered a recorded version of the MMSE in background noise at a signal-to-noise ratio of +25-dB SNR. Control participants were administered a digitally filtered version of the MMSE that reflected the loss of audibility (i.e., threshold elevation) of the matched case participant at a signal-to-noise ratio of +25-dB SNR. Performance on the MMSE was scored using standard criteria. Between-group analyses revealed no significant difference in the MMSE score. However, within-group analyses showed that education was a significant effect modifier for the case participants. Reduced audibility has a negative effect on MMSE score in cognitively intact participants, which contributes to and confirms the findings of earlier studies. The findings suggest that observed reductions in score on the MMSE were primarily due to loss of audibility of the test item. The negative effects of audibility loss may be greater in individuals who have lower levels of educational attainment. Higher levels of educational attainment may offset decreased performance on the MMSE because of reduced audibility. Failure to consider audibility and optimize communication when administering these assessments can lead to invalid results (e.g., false positives or missed information), misdiagnosis, and inappropriate recommendations for medication or intervention.

Prevention of Hearing Loss by Alteration of the Systemic Immune System

Although congenital sensorineural hearing loss (SHL) in the bilateral cochleae mainly results from genetic abnormalities, chronic SHL progressing in later life is often influenced by systemic immune disturbances, including autoimmunity, chronic inflammation, and immunosenescence. We have investigated the relationship between the inner ear and systemic immunity and reviewed the possibilities to prevent SHL, including autoimmune SHL and age-related SHL. We also demonstrated two lymphocyte populations, interleukin 1 receptor type II (IL-1R2)-positive T cells (T1R2) and naturally occurring regulatory T cells (nTregs) in CD4+ T cells, which increase with aging, suppress host immune function and promote organ degeneration. Alterations in systemic immunity by fewer microbial antigen challenges in the living environment, elimination of immune suppressive lymphocytes, or immune rejuvenation with a reconstituted thymus may contribute not only to renew the cochlear function in SHL, but also to extend the healthy life of functional organs in a vigorous and youthful body, one of humanity’s greatest dreams.