The Effects of Hearing Loss on Balance: A Critical Review

Increased risk of falls in older adults with hearing loss and slow gait: results from the Otassha Study

Age-related hearing loss (ARHL) and impaired gait both independently heighten the risk of accidental falls among older adults. However, the combined impact of these factors remains unclear. We analyzed the data of 786 community-dwelling Japanese older adults. Hearing was evaluated at frequencies of 1.0 and 4.0 kHz, with participants categorized into ARHL (> 25 dB) and non-ARHL groups. Gait was also assessed, defining slow gait (SG) as speeds one standard deviation below the age- and sex-specific mean. Participants were divided into four groups based on their ARHL and SG statuses and were monitored annually for 8 years to track falls and related injuries. Throughout the follow-up, incidents included 328 single falls (9.6/100 person-years), 117 multiple falls (2.8/100 person-years), 249 minor injuries from falls (6.7/100 person-years), and 55 fractures due to falls (1.3/100 person-years). Cox proportional hazard regression models showed that participants without ARHL but with SG faced a significantly increased risk of frequent falls. Furthermore, ARHL combined with SG significantly raised the risk of both single and frequent falls, and increased the incidence of both minor and severe fall-related injuries, including fractures. In contrast, no significant association was found between ARHL alone and fall-related incidents. These findings suggest that the previously reported risk associated with hearing loss in fall incidents predominantly relates to gait impairment. The co-occurrence of ARHL and SG significantly escalates the risk of falls and related injuries, highlighting the critical need for routine gait monitoring.

Associations between hearing loss, peripheral neuropathy, balance, and survival in older primary care patients

BACKGROUND

Both age-associated hearing loss (AAHL) and peripheral neuropathy (PN) are common in older patients, and both are associated with impaired balance, falls, and premature mortality. The objectives of this study were to document the prevalence and severity of AAHL in older primary care patients, and to explore associations between AAHL, PN, balance, falls, and mortality.

METHODS

We analyzed information obtained in 1999 from 793 primary care patients recruited from practices participating in the Oklahoma Longitudinal Assessment of the Health Outcomes of Mature Adults (OKLAHOMA) Studies. Available data included demographic and health information, history of falls and hospitalizations, audiometry, balance testing, examination of the peripheral nerves, 50 foot timed gait, and dates of death up to 22 calendar years and 8106 person-years of follow-up. Proportionate hazards (PH) and structural equation modeling (SEM) were used to examine associations between AAHL, PN, balance, gait time, and mortality.

RESULTS

501 of the 793 participants (63%) had AAHL. Another 156 (20%) had low frequency and 32 (4%) had unilateral deficits. Those with moderate or severe AAHL and the 255 (32%) with PN had impaired balance (p < 0.0001), increased gait time (p = 0.0001), and reduced survival time (p < 0.0001). In the PH model, both AAHL and PN were associated with earlier mortality (H.Rs. [95% C.I.]: 1.36 [1.13-1.64] and 1.32 [1.10-1.59] respectively). The combination of moderate or severe AAHL and PN, present in 24% of participants, predicted earlier mortality than predicted by either deficit alone (O.R. [95% C.I.I] 1.55 [1.25-1.92]). In the SEM models, the impacts of both moderate or severe AAHL and PN on survival were mediated, in part, through loss of balance.

CONCLUSIONS

Hearing loss and PN, both common in older patients, appear to be independently and additively associated with premature mortality. Those associations may be mediated in part by impaired balance. The Mechanisms are likely multiple and complex.

Vibration Thresholds Using Conventional Audiometry are Clinically Useful Indicators of Postural Instability in Older Adults

BACKGROUND

 Falls are a major health concern with potentially dramatic consequences for people over 65 years of age. One crucial determinant in the risk of falls in older adults is postural control, a complex process that requires the contribution of different sensory modalities, namely visual, vestibular, auditory, and somatosensory. While there are well-established methods to screen for age-related vision, hearing, tactile, and vestibular impairments, there are very few widely available methods to screen for somatosensory function, but studies indicate that ankle audiometry (vibration thresholds) using a common B-71 bone vibrator can serve that purpose. To date, unfortunately, this technique has received little attention as a tool to measure postural instability in older adults.

PURPOSE

 The objective of the present study was to examine postural control in older adults with and without degradation of the somatosensory functions, as determined with ankle audiometry.

RESEARCH DESIGN

 This was standard group comparison.

STUDY SAMPLE

 In total, 36 healthy elderly aged between 65 and 80 years old were divided into two groups (low vibration threshold [n = 18] and high vibration threshold [n = 18]).

DATA COLLECTION AND ANALYSIS

 Standard audiometry, video head impulse test, vibration thresholds (big toe, ankle, and tibia), and static postural control task using a force platform were performed.

RESULTS

 Greater postural instability in participants with higher (worse) vibration thresholds as compared with participants with lower (better) vibration thresholds was observed even though both groups were comparable on hearing threshold and vestibular function.

CONCLUSION

 The results indicate that performing a simple vibration threshold evaluation, using a clinically available B-71 with a cut-off value of 42 dB hearing loss, could be an effective, fast, and easy-to-use procedure for detecting people at risk of falls.

Walking and balance in older adults with age-related hearing loss: A cross-sectional study of cases and matched controls

BACKGROUND

Hearing loss (HL) is prevalent in older individuals. It is suggested that there is an association between age-related HL, walking and balance, leading to poorer function and increased risk of falls in older individuals.

RESEARCH QUESTION

Is HL associated with physical performance, gait variability, and postural sway in older adults, and will additional dizziness moderate the effect of HL on balance?

METHODS

In this cross-sectional study we examined 100 older individuals (age ≥70 years, 60 % females), divided in two groups, with or without age-related HL. Physical function and balance were evaluated by the Short Physical Performance Battery (SPPB), postural sway measured on a force platform (posturography), and balance in walking (gait variability) measured with a body-worn sensor. Multiple linear regression was used to examine the relationships between the variables, with physical function and balance as outcomes and HL as a dichotomous exposure (>30 dB). For all analyses, we further tested if associations were modified by self-reported dizziness.

RESULTS

Multiple regression analysis with HL, age, sex, education, diabetes, and cardiovascular disease revealed a significant association between reduced SPPB and HL. Multiple linear regression analysis also showed that HL was associated with increased postural sway on firm surface with eyes open and closed after adjusting for age, sex, education, diabetes, and cardiovascular disease. There was significant association between HL and increased gait variability during dual task walking in all directions after adjusting for age, sex, education, diabetes, and cardiovascular disease. Further, we found that the association between HL and SPPB was significantly stronger in those with dizziness compared with those without dizziness. Dizziness also modified the association of HL with the other SPPB sub-scores but not for the other outcomes of postural sway or gait variability.

SIGNIFICANCE

In this study, age-related HL was associated with worse physical performance as measured by SPPB, postural sway, and gait variability. This relationship illustrates the importance of assessing physical performance in people with HL to prevent risk of falls and disability.

Associations of frailty, self-reported balance problems, hearing abilities, and posturography in a sample of older adults

OBJECTIVE

The aim of this study was to identify risk factors for self-reported balance problems, and to analyse associations between hearing and balance.

DESIGN

A battery of tests was administered to assess hearing and balance performance, as well as additional health-related factors indicative of frailty and fall risk. In a retrospective analysis, logistic regression was used to identify risk factors for self-reported balance problems and linear regression was used to identify associations between hearing ability and functional balance.

STUDY SAMPLE

For the risk factor analysis, 199 volunteers aged 55-81 years (mean:67) were divided into two groups according to their self-reported balance problems. Only participants lacking self-reported balance problems (n = 157) were included in the second analysis.

RESULTS

Female gender, frailty, and fine-motor skills were statistically significant predictors of self-reported balance problems. Functional balance performance was related to hearing impairment for dynamic, but not for static, balance tasks.

CONCLUSION

For a holistic approach to healthcare and regardless of age, individuals with multiple comorbidities and/or phenotypic signs of frailty should be considered at risk for falls. For further research, it was shown that dynamic, rather than static, balance tasks may be needed to gain deeper insights into the relationship between hearing and balance.

Prevalence and risk factors of self-reported hearing loss, tinnitus, and dizziness in a population-based sample from rural northeastern Germany

A close anatomical and physiological relationship is known between the senses of hearing and balance, while an additional pathophysiological interaction is supposed. The mechanisms underlying this association are not yet fully understood, especially in individuals without a known specific otologic disorder. In particular, only scarce information on the combined occurrence of audiovestibular sensory impairment is available so far. Therefore, this study aims to provide further insight into the prevalence and co-prevalence of the audiovestibular symptoms hearing loss, tinnitus and dizziness. Additionally, the influence of potential risk factors from lifestyle habits as well as cardiovascular and metabolic conditions on the development of those symptoms is studied. Data was analyzed from 8134 individuals from the population-based Study of Health in Pomerania (SHIP). SHIP pursues a broad and comprehensive examination program in chronologically separated cohorts with longitudinal follow-up. Cohorts are sampled from Western Pomerania, a rural region of north-eastern Germany. The study population represents a cross-sectional analysis from the cohorts SHIP-START (recruited 1997-2001) and SHIP-TREND (recruited 2008-2012), sampled for baseline investigations (SHIP-START-0 and SHIP-TREND-0) at the age of 20-79 years. Audiovestibular symptoms as outcome variables were assessed by structured questionnaires. Additionally, individuals were comprehensively characterized regarding modifiable lifestyle factors as well as cardiovascular and metabolic disorders, allowing the assessment of their role as exposure variables. We calculated a weighted prevalence of 14.2% for hearing loss, 9.7% for tinnitus, and 13.5% for dizziness in the population. Prevalence increased with age and differed among the sexes. A considerable share of 28.0% of the investigated individuals reported more than one symptom at once. The prevalence of hearing loss as well as tinnitus increased between the two cohorts. A moderate positive correlation was found between the occurrence of hearing loss and tinnitus (phi-coefficient 0.318). In multivariable regression analyses, education was identified as a significant protective factor while only smoking was significantly associated with all three symptoms. Furthermore, several cardiovascular risk factors contributed to both hearing loss and dizziness. In conclusion, audiovestibular symptoms are highly prevalent in the investigated population. A considerable but complex influence of risk factors points towards a relation with neuronal as well as cardiovascular disease processes. To clarify the underlying mechanisms, the interaction between the senses of hearing and balance as well as the mode of action of the risk factors should be evaluated in more detail in the future.

Association Between Hearing Loss, Asymmetric Hearing, and Postural Instability

OBJECTIVES

Recent studies have suggested that older adults with hearing loss (HL) are at a greater risk of postural instability than those with normal hearing. However, little is known regarding this association in middle-aged individuals. The relationships between HL laterality, asymmetric hearing, and posture control are similarly unclear. The purpose of this study was to investigate the effects of hearing status on postural control and to explore the dose-response relationship between the hearing threshold and postural instability risk in middle-aged adults.

DESIGN

This cross-sectional study included 1308 participants aged 40 to 69 years with complete audiometric and standing balance function data from the 2001-2004 National Health and Nutrition Examination Survey. Speech-frequency HL was defined as a pure-tone average at 0.5, 1, 2, and 4 kHz of >25 dB in the better-hearing ear; high-frequency HL was defined as a pure-tone average at 3, 4, and 6 kHz of >25 dB. Asymmetric hearing was defined as a difference in the pure-tone average >15 dB between ears. Postural instability was defined as participants ending the modified Romberg test in condition 4.

RESULTS

After adjustment for sociodemographic variables, lifestyle, and comorbidities, speech-frequency HL, except for unilateral HL, was associated with increased postural instability (mild HL: odds ratio [OR], 2.33; 95% confidence interval [CI], 1.25-4.35; moderate-to-severe HL: OR, 3.59; 95% CI, 1.61-8.03). Compared with individuals with normal bilateral hearing, participants with bilateral HL also showed a higher risk of postural instability (OR, 2.88; 95% CI, 1.61-5.14). The OR for postural instability among participants with asymmetric hearing compared with those with symmetric hearing was 2.75 (95% CI, 1.37-5.52). Furthermore, each 10 dB increase in the speech-frequency hearing threshold was associated with a 44% higher risk of postural instability.

CONCLUSIONS

Hearing loss is associated with poorer postural control. Individuals with asymmetric hearing have a higher postural instability risk compared with those with symmetric hearing. Further studies are needed to confirm these findings and the causality. Moreover, future studies are warranted to assess whether hearing aids are beneficial for the restoration of impaired balance functions.

Association of Single and Dual Sensory Impairment with Falls among Medicare Beneficiaries

Objective: The purpose of this study was to determine if dual sensory impairment (DSI) is associated with falls and fear of falling among older adults. Methods: Using data from the 2019 Medicare Current Beneficiary Survey (MCBS), we studied the cross-sectional association of self-reported hearing/vision impairment with self-reported history/number of falls over the past year, fear of falling (scale 1-6), and a fall requiring medical help using weighted multivariable regressions adjusted for demographic and clinical covariates. Results: Among 11,089 Medicare beneficiaries (mean age = 74, 55% female, 9% Black), DSI is associated with increased prevalence (prevalence ratio = 1.45 [1.28-1.65]) and incidence (incidence ratio = 2.21 [1.79-2.75]) rate of falls, and greater odds of a higher fear of falling score (odds ratio = 1.38 [1.08-1.77]). Discussion: DSI is associated with falls among older adults. Consideration of DSI as a marker to initiate fall prevention programs and inclusion of sensory interventions in these programs may be valuable.

Hearing loss, gait and balance impairments and falls among individuals with sub-acute stroke: A comparative cross-sectional study

Background

The impact of hearing loss in stroke is less explored. This study aimed to compare hearing loss in patients with sub-acute stroke with healthy controls and evaluate its association with gait and balance impairments and falls.

Methods

This study involved 78 ambulant sub-acute stroke patients and 78 age-sex-matched controls. Hearing loss was assessed with pure tone average, while gait and balance impairments were assessed with the Timed Up and Go test, Berg Balance Scale, Functional Gait Assessment and 10-m walk test (gait speed). Fall occurrence was evaluated by a self-report questionnaire.

Results

The prevalence of hearing loss (pure tone average of >25 dB) was higher in stroke patients than in controls (64.1% vs. 35.9%; p < 0.001). The mean pure tone average of stroke patients showed a significant positive correlation with Timed Up and Go test (r = 0.357; p = 0.001) and fall occurrence (r = 0.253; p = 0.025), and a significant negative correlation with Berg Balance Scale (r = -0.299; p = 0.008) and Functional Gait Assessment (r = -0.452; p < 0.001). There was a non-significant negative correlation with gait speed (r = -0.166; p = 0.147). Multiple regression showed that mean pure tone average was associated with Timed Up and Go test (B = 0.096; 95%CI: 0.010, 0.183) and Functional Gait Assessment (B = -0.087; 95%CI: -0.157, -0.017), but not with gait speed (B = -0.003; 95%CI: -0.007, 0.001) and Berg Balance Scale (B = -0.058; 95%CI: -0.165, 0.049).

Conclusion

Hearing loss is more prevalent among patients with sub-acute stroke compared with age-sex-matched controls. Hearing loss is also associated with gait and balance impairments and falls among sub-acute stroke patients. We recommend that hearing screening and rehabilitation be incorporated into post-stroke rehabilitation programmes as part of strategies to improve balance and gait and reduce or prevent falls.

Ten-year association between change in speech-in-noise recognition and falls due to balance problems: a longitudinal cohort study

BACKGROUND

This study examined the relationship between speech-in-noise recognition and incident/recurrent falls due to balance problems ten years later (RQ-1); 10-year change in speech-in-noise recognition and falls (RQ-2a), as well as the role of dizziness in this relationship (RQ-2b). The association between hearing aid use and falls was also examined (RQ-3).

METHODS

Data was collected from the Netherlands Longitudinal Study on Hearing between 2006 and December 2022. Participants completed an online survey and digits-in-noise test every five years. For this study, data was divided into two 10-year follow-up time intervals: T0 (baseline) to T2 (10-year follow-up), and T1 (5-years) to T3 (15-years). For all RQs, participants aged ≥ 40 years at baseline, without congenital hearing loss, and non-CI users were eligible (n = 592). Additionally, for RQ-3 participants with a speech reception threshold in noise (SRTn) ≥ -5.5 dB signal-to-noise ratio were included (n = 422). Analyses used survey variables on hearing, dizziness, falls due to balance problems, chronic health conditions, and psychosocial health. Logistic regressions using General Estimating Equations were conducted to assess all RQs.

RESULTS

Among individuals with obesity, those with poor baseline SRTn had a higher odds of incident falls ten years later (odds ratio (OR):14.7, 95% confidence interval (CI) [2.12, 103]). A 10-year worsening of SRTn was significantly associated with a higher odds of recurrent (OR: 2.20, 95% CI [1.03, 4.71]) but not incident falls. No interaction was found between dizziness and change in SRTn. Hearing aid use (no use/ < 2 years use vs. ≥ 2 years) was not significantly associated with incident nor recurrent falls. Although there was a significant interaction with sex for this association, the effect of hearing aid use on incident/recurrent falls was not statistically significant among males nor females.

CONCLUSIONS

A longitudinal association between the deterioration in SRTn and recurrent falls due to balance problems after 10 years was confirmed in this study. This result stresses the importance of identifying declines in hearing earlier and justifies including hearing ability assessments within fall risk prevention programs. Mixed results of hearing aid use on fall risk warrant further investigation into the temporality of this association and possible differences between men and women.

The Effects of Core Stabilization Exercises on Respiratory Muscle Strength, Respiratory Functions, and Postural Control in Children With Hearing Loss: A Randomized Controlled Trial

OBJECTIVES

To evaluate the effects of core stabilization training on respiratory muscle strength, respiratory functions, and postural control in children with hearing loss.

DESIGN

We conducted a randomized controlled trial at Bezmialem Vakif University, Faculty of Health Sciences, Division of Physiotherapy and Rehabilitation. Thirty children with hearing loss who were diagnosed with prelingual sensorineural hearing loss were randomly allocated to the study (n = 15, 12.20 ± 1.69 years) and control (n = 15, 11.87 ± 2.20 years) groups. Core stabilization training protocol was performed by the study group for 8 weeks, 5 days/week, whereas the control group received no training. The primary outcome measure was respiratory muscle strength. The secondary outcome measures were: spirometry, postural control tests on Biodex Balance System, and Balance Error Scoring System (BESS). Exercise adherence was recorded via a diary for home sessions. Outcomes were assessed at baseline and the end of the 8 weeks.

RESULTS

In the study group, a significant improvement was observed in force vital capacity, peak expiratory flow of the spirometry test, maximum inspiratory pressure/expiratory pressure (MEP) of the respiratory muscle strength test; postural stability test except "anterior/posterior stability index", limits of stability test except "backward" and "forward/right", all parameters of the Modified Clinical Test for Sensory Interaction and Balance (mCTSIB) test except "eyes closed firm surface" of the Biodex Balance System, and total score of BESS. Group × time interaction was found in MEP, "overall" stability index in postural stability test, "overall," "left," and "backward left" of limits of stability test, all parameters of the mCTSIB, and BESS total.

CONCLUSIONS

Core stabilization exercises were effective in improving respiratory muscle strength, spirometry, and postural control in children with hearing loss.

Hearing Aid Amplification Improves Postural Control for Older Adults With Hearing Loss When Other Sensory Cues Are Impoverished

Recent studies suggest that sound amplification via hearing aids can improve postural control in adults with hearing impairments. Unfortunately, only a few studies used well-defined posturography measures to assess balance in adults with hearing loss with and without their hearing aids. Of these, only two examined postural control specifically in the elderly with hearing loss. The present study examined the impact of hearing aid use on postural control during various sensory perturbations in older adults with age-related hearing loss. Thirty individuals with age-related hearing impairments and using hearing aids bilaterally were tested. Participants were asked to perform a modified clinical sensory integration in balance test on a force platform with and without hearing aids. The experiment was conducted in the presence of a broadband noise ranging from 0.1 to 4 kHz presented through a loudspeaker. As expected, hearing aid use had a beneficial impact on postural control, but only when visual and somatosensory inputs were both reduced. Data also suggest that hearing aid use decreases the dependence on somatosensory input for maintaining postural control. This finding can be of particular importance in older adults considering the reduction of tactile and proprioceptive sensitivity and acuity often associated with aging. These results provide an additional argument for encouraging early hearing aid fitting for people with hearing loss.

At-home computerized executive-function training to improve cognition and mobility in normal-hearing adults and older hearing aid users: a multi-centre, single-blinded randomized controlled trial

BACKGROUND

Hearing loss predicts cognitive decline and falls risk. It has been argued that degraded hearing makes listening effortful, causing competition for higher-level cognitive resources needed for secondary cognitive or motor tasks. Therefore, executive function training has the potential to improve cognitive performance, in turn improving mobility, especially when older adults with hearing loss are engaged in effortful listening. Moreover, research using mobile neuroimaging and ecologically valid measures of cognition and mobility in this population is limited. The objective of this research is to examine the effect of at-home cognitive training on dual-task performance using laboratory and simulated real-world conditions in normal-hearing adults and older hearing aid users. We hypothesize that executive function training will lead to greater improvements in cognitive-motor dual-task performance compared to a wait-list control group. We also hypothesize that executive function training will lead to the largest dual-task improvements in older hearing aid users, followed by normal-hearing older adults, and then middle-aged adults.

METHODS

A multi-site (Concordia University and KITE-Toronto Rehabilitation Institute, University Health Network) single-blinded randomized controlled trial will be conducted whereby participants are randomized to either 12 weeks of at-home computerized executive function training or a wait-list control. Participants will consist of normal-hearing middle-aged adults (45-60 years old) and older adults (65-80 years old), as well as older hearing aid users (65-80 years old, ≥ 6 months hearing aid experience). Separate samples will undergo the same training protocol and the same pre- and post-evaluations of cognition, hearing, and mobility across sites. The primary dual-task outcome measures will involve either static balance (KITE site) or treadmill walking (Concordia site) with a secondary auditory-cognitive task. Dual-task performance will be assessed in an immersive virtual reality environment in KITE's StreetLab and brain activity will be measured using functional near infrared spectroscopy at Concordia's PERFORM Centre.

DISCUSSION

This research will establish the efficacy of an at-home cognitive training program on complex auditory and motor functioning under laboratory and simulated real-world conditions. This will contribute to rehabilitation strategies in order to mitigate or prevent physical and cognitive decline in older adults with hearing loss.

TRIAL REGISTRATION

Identifier: NCT05418998. https://clinicaltrials.gov/ct2/show/NCT05418998.

Sensory functions and their relation to balance metrics: a secondary analysis of the LIMBIC-CENC multicenter cohort

Introduction

Among patients with traumatic brain injury (TBI), balance problems often persist alongside hearing and vision impairments that lead to poorer outcomes of functional independence. As such, the ability to regain premorbid independent gait may be dictated by the level of sensory acuity or processing decrements that are shown following TBI assessment. This study explores the relationships between standardized sensory acuity and processing outcomes to postural balance and gait speed.

Methods

Secondary analysis was performed on the Long-Term Impact of Military- Relevant Brain Injury Consortium Chronic Effects of Neurotrauma Consortium LIMBIC (CENC) data set. Separate regression analyses were carried out for each of the balance assessments (via Computerized Dynamic Posturography, CDP) and walking speed.

Discussion

TBI frequency was significantly related to the majority of single CDP outcomes (i.e., Conditions 2-6), while various sensory processing outcomes had task-specific influences. Hearing impairments and auditory processing decrements presented with lower CDP scores (CDP Conditions 3,5,6, and 1-3 respectively), whereas greater visual processing scores were associated with better CDP scores for Conditions 2,5, and 6. In sum, patients with TBI had similar scores on static balance tests compared to non-TBI, but when the balance task got more difficult patients with TBI scored worse on the balance tests. Additionally, stronger associations with sensory processing than sensory acuity measures may indicate that patients with TBI have increased fall risk.

Subtle alterations of vestibulomotor functioning in conductive hearing loss

Introduction

Conductive hearing loss (CHL) attenuates the ability to transmit air conducted sounds to the ear. In humans, severe hearing loss is often accompanied by alterations to other neural systems, such as the vestibular system; however, the inter-relations are not well understood. The overall goal of this study was to assess vestibular-related functioning proxies in a rat CHL model.

Methods

Male Sprague-Dawley rats (N=134, 250g, 2months old) were used in a CHL model which produced a >20dB threshold shift induced by tympanic membrane puncture. Auditory brainstem response (ABRs) recordings were used to determine threshold depth at different times before and after CHL. ABR threshold depths were assessed both manually and by an automated ABR machine learning algorithm. Vestibular-related functioning proxy assessment was performed using the rotarod, balance beam, elevator vertical motion (EVM) and Ferris-wheel rotation (FWR) assays.

Results

The Pre-CHL (control) threshold depth was 27.92dB±11.58dB compared to the Post-CHL threshold depth of 50.69dB±13.98dB (mean±SD) across the frequencies tested. The automated ABR machine learning algorithm determined the following threshold depths: Pre-CHL=24.3dB, Post-CHL same day=56dB, Post-CHL 7 days=41.16dB, and Post-CHL 1 month=32.5dB across the frequencies assessed (1, 2, 4, 8, 16, and 32kHz). Rotarod assessment of motor function was not significantly different between pre and post-CHL (~1week) rats for time duration (sec) or speed (RPM), albeit the former had a small effect size difference. Balance beam time to transverse was significantly longer for post-CHL rats, likely indicating a change in motor coordination. Further, failure to cross was only noted for CHL rats. The defection count was significantly reduced for CHL rats compared to control rats following FWR, but not EVM. The total distance traveled during open-field examination after EVM was significantly different between control and CHL rats, but not for FWR. The EVM is associated with linear acceleration (acting in the vertical plane: up-down) stimulating the saccule, while the FWR is associated with angular acceleration (centrifugal rotation about a circular axis) stimulating both otolith organs and semicircular canals; therefore, the difference in results could reflect the specific vestibular-organ functional role.

Discussion

Less movement (EVM) and increase time to transverse (balance beam) may be associated with anxiety and alterations to defecation patterns (FWR) may result from autonomic disturbances due to the impact of hearing loss. In this regard, vestibulomotor deficits resulting in changes in balance and motion could be attributed to comodulation of auditory and vestibular functioning. Future studies should manipulate vestibular functioning directly in rats with CHL.

Association of Bilateral Vestibulopathy With and Without Hearing Loss With Cognitive-Motor Interference

Importance

The past years, evidence suggested that the primary symptoms traditionally associated with bilateral vestibulopathy (BV) do not represent the full picture of this patient population. Recent literature also demonstrated cognitive impairment. However, although multitasking and dual-tasking are widely present in everyday activities, most of these studies assessed cognitive function only in single-task conditions.

Objective

To uncover the association of BV with and without hearing loss with cognitive and motor performance and cognitive-motor interference.

Design, Setting, and Participants

This prospective case-control study assessed persons with an isolated BV and persons with BV and a concomitant hearing loss compared with a healthy control group. Data were analyzed in December 2022. The study was conducted at Ghent University (Ghent, Belgium). Data collection took place between March 26, 2021, and November 29, 2022.

Main Outcomes and Measures

All participants completed the 2BALANCE dual-task protocol, comprising a static and a dynamic motor task that was combined with 5 visual cognitive tasks. These cognitive tasks assessed mental rotation, visuospatial memory, working memory, response inhibition (executive function), and processing speed. All cognitive tasks were performed in a single-task condition (while seated) and in a dual-task condition (combined with a static and a dynamic motor task). The static task comprised balancing on a force platform with foam pad, and the dynamic task comprised walking at a self-selected speed on the GAITRite Walkway. Both motor tasks were performed in the single-task and dual-task condition.

Results

Nineteen persons with BV and hearing loss (mean [SD] age, 56.70 [10.12] years; 10 women [52.6%]), 22 persons with an isolated BV (mean [SD] age, 53.66 [13.35] years; 7 women [31.8%]), and 28 healthy control participants were included (mean [SD] age, 53.73 [12.77] years; 12 women [42.9%]). Both patient groups had mental rotation and working memory impairment in a single-task condition and slower processing speed when walking (ie, during the dynamic dual-task condition). Additionally, the patient group with hearing loss had impaired visuospatial memory and executive function deficits in single-task and dual-task conditions, while this could only be elicited when performing a motor task in persons with isolated BV (ie, when dual-tasking).

Conclusion and Relevance

The findings of this case-control study suggest an association between vestibular function and cognitive and motor performance, even greater in persons with a concomitant hearing loss than in persons with an isolated BV.

Differing postural control patterns in individuals with bilateral and unilateral hearing loss

OBJECTIVES

Hearing loss (HL) is associated with imbalance and increased fall risk. The mechanism underlying this relationship and differences across types of hearing loss remains unclear. Head mounted displays (HMD) can shed light on postural control mechanisms via an analysis of head sway.

PURPOSE

The purpose of this study was to evaluate head sway in response to sensory perturbations in individuals with bilateral (BHL) or unilateral hearing loss (UHL) and compare them to controls.

MATERIALS AND METHODS

We recruited 36 controls, 23 individuals with UHL and 14 with BHL. An HMD (HTC Vive) measured head sway while participants stood on the floor, hips-width apart. Stimuli included two levels of visuals and sound. Root Mean Square Velocity (RMSV) and Power Spectral Density (PSD) were used to quantify head sway.

RESULTS

Adjusting for age, individuals with BHL had significantly higher anterior-posterior and medio-lateral RMSV than controls and individuals with UHL. Individuals with UHL demonstrated significantly lower response to visual perturbations in RMSV AP and in all 3 frequency segments of PSD compared to controls. Individuals with UHL showed significantly lower movements at high frequencies compared to controls. Sounds or severity of HL did not impact head sway.

CONCLUSIONS

Individuals with BHL demonstrated increased sway with visual perturbations and should be clinically assessed for balance performance and fall risk. Individuals with UHL exhibited reduced responses to visual stimuli compared with controls, which may reflect conscious movement processing. Additional studies are needed to further understand the mechanistic relationship between hearing loss and imbalance.

Interaction of Hearing and Balance

There is increasingly assumed that, in addition to visual, vestibular and somatosensory afferents, hearing also plays a role in the regulation of balance. It seems that, especially in old age, progressive hearing loss is associated with a decrease in postural control. Several studies investigated this relationship in normal-hearing people, in patients with conventional hearing aids and with implantable hearing systems, as well as in patients with vestibular disorders. Despite the inhomogeneous study situation and lack of evidence, hearing seems to interact with the balance regulation system with potentially stabilizing effect. Furthermore, insights into audiovestibular interaction mechanisms could be achieved, which could possibly be integrated into therapeutic concepts of patients with vestibular disorders. However, further prospective controlled studies are necessary to bring this issue to an evidence-based level.

Hearing threshold and physical performance in older people: a cross-sectional study from the HUNT4 cohort

PURPOSE

To evaluate the association between increased hearing loss and reduced physical performance in older people.

METHODS

Cross-sectional population-based study using data from the fourth wave of the Trøndelag Health Survey (HUNT4) in Norway. Data were obtained from the subproject HUNT4 Hearing which collected audiometric data of people > 70 years (N = 13,197). Analyses were performed on all participants who had completed audiometry and measured balance using the Short Physical Performance Battery (SPPB), which was scored from 0 (worst score) to 12. The hearing threshold was expressed as a pure tone average (PTA). Associations between the hearing threshold for the best and worst ear and physical performance were analyzed by linear regression models adjusted for age, sex, education, diabetes, and cardiovascular disease. Hearing threshold was indicated with steps of 10 dB.

RESULTS

Of 13,197 eligible participants, 4101 who completed audiometry and SPPB (52.3% women. mean age 76.3 years) were included. The analyses revealed an association between reduced SPPB and increased hearing threshold in the best ear (b = - 0.296; 95% CI - 0.343 to - 0. 249; P < 0.001) and the worst ear (b = - 0.229; 95% CI - 0.270 to - 0.189; P < 0.001).

CONCLUSIONS

In this population study, we found that the increased hearing threshold was associated to reduced physical performance as measured by SPPB. The association seemed to be strongest for the best ear. The association between hearing threshold and physical performance illustrates the importance of assessing physical performance in people with hearing loss to prevent the risk of falls and disability. The underlying causes of the associations between hearing loss and poorer physical performance are not fully understood and should be further investigated.

LEVEL OF EVIDENCE

Level 3.

The significance of right ear auditory processing to balance

Although the association between balance and hearing thresholds at different frequencies in the right/left ear is crucial, it has received scant empirical attention. Balance is widely ignored when evaluating hearing in adults. This study examined the relative contribution of left versus right ear hearing at different frequencies to balance, and the mediating role of suprathreshold speech perception on age-balance associations. Pure tone hearing thresholds (500-4000 Hz), suprathreshold speech perception, balance, and risk of falling were evaluated in 295 adults. The results indicate that the right ear contributes more to balance than the left ear. This might imply dominance of the left hemisphere in processing hearing cues for balance. Frequencies within the speech range (500/1000/2000 Hz) were correlated with balance and mediated the interaction between age and balance. These results should be considered when tailoring hearing and balance rehabilitation programs.

A Systematic Review of the Effect of Hearing Aids on Static and Dynamic Balance in Adults with Hearing Impairment

This preregistered systematic review examined the peer-reviewed scientific literature to determine the effect of hearing aids (HAs) on static and dynamic balance in adults with Hearing Impairment (HI). A search of the English language literature in seven academic databases identified 909 relevant articles published prior to July 2021. Ten articles contained studies that met the inclusion criteria for this review. Seven studies had measured static balance with five reporting improvements and one reporting no changes in balance with HA use. Two studies had measured dynamic balance with both reporting no changes with HA use. One study had measured both dynamic and static balance and reported no changes with HA use. For adults with HI, the evidence was equivocal that amplification from HAs improves balance. High quality studies investigating the effect of HAs on balance in adults with HI are needed given this field is likely to develop in response to the growing population of adults with hearing and balance impairment worldwide.

Insight into postural control in unilateral sensorineural hearing loss and vestibular hypofunction

This pilot study aimed to identify postural strategies in response to sensory perturbations (visual, auditory, somatosensory) in adults with and without sensory loss. We tested people with unilateral peripheral vestibular hypofunction (N = 12, mean age 62 range 23-78), or with Unilateral Sensorineural Hearing Loss (USNHL, N = 9, 48, 22-82), or healthy controls (N = 21, 52, 28-80). Postural sway and head kinematics parameters (Directional Path in the anterior-posterior and medio-lateral directions (sway & head); pitch, yaw and roll (head) were analyzed in response to 2 levels of auditory (none, rhythmic sounds via headphones), visual (static, dynamic) and somatosensory cues (floor, foam) within a simulated, virtual 3-wall display of stars. We found no differences with the rhythmic auditory cues. The effect of foam was magnified in the vestibular group compared with controls for anterior-posterior and medio-lateral postural sway, and all head direction except for medio-lateral. The vestibular group had significantly larger anterior-posterior and medio-lateral postural sway and head movement on the static scene compared with controls. Differences in pitch, yaw and roll emerged between vestibular and controls only with sensory perturbations. The USNHL group did not increase their postural sway and head movement with the increased visual load as much as controls did, particularly when standing on the foam. They did not increase their medio-lateral sway with the foam as much as controls did. These findings suggest that individuals with USNHL employ a compensatory strategy of conscious control of balance, the functional implications of which need to be tested in future research.

Profiling hearing aid users through big data explainable artificial intelligence techniques

Debilitating hearing loss (HL) affects ~6% of the human population. Only 20% of the people in need of a hearing assistive device will eventually seek and acquire one. The number of people that are satisfied with their Hearing Aids (HAids) and continue using them in the long term is even lower. Understanding the personal, behavioral, environmental, or other factors that correlate with the optimal HAid fitting and with users' experience of HAids is a significant step in improving patient satisfaction and quality of life, while reducing societal and financial burden. In SMART BEAR we are addressing this need by making use of the capacity of modern HAids to provide dynamic logging of their operation and by combining this information with a big amount of information about the medical, environmental, and social context of each HAid user. We are studying hearing rehabilitation through a 12-month continuous monitoring of HL patients, collecting data, such as participants' demographics, audiometric and medical data, their cognitive and mental status, their habits, and preferences, through a set of medical devices and wearables, as well as through face-to-face and remote clinical assessments and fitting/fine-tuning sessions. Descriptive, AI-based analysis and assessment of the relationships between heterogeneous data and HL-related parameters will help clinical researchers to better understand the overall health profiles of HL patients, and to identify patterns or relations that may be proven essential for future clinical trials. In addition, the future state and behavioral (e.g., HAids Satisfiability and HAids usage) of the patients will be predicted with time-dependent machine learning models to assist the clinical researchers to decide on the nature of the interventions. Explainable Artificial Intelligence (XAI) techniques will be leveraged to better understand the factors that play a significant role in the success of a hearing rehabilitation program, constructing patient profiles. This paper is a conceptual one aiming to describe the upcoming data collection process and proposed framework for providing a comprehensive profile for patients with HL in the context of EU-funded SMART BEAR project. Such patient profiles can be invaluable in HL treatment as they can help to identify the characteristics making patients more prone to drop out and stop using their HAids, using their HAids sufficiently long during the day, and being more satisfied by their HAids experience. They can also help decrease the number of needed remote sessions with their Audiologist for counseling, and/or HAids fine tuning, or the number of manual changes of HAids program (as indication of poor sound quality and bad adaptation of HAids configuration to patients' real needs and daily challenges), leading to reduced healthcare cost.

Multisensory visual-vestibular training improves visual heading estimation in younger and older adults

Self-motion perception (e.g., when walking/driving) relies on the integration of multiple sensory cues including visual, vestibular, and proprioceptive signals. Changes in the efficacy of multisensory integration have been observed in older adults (OA), which can sometimes lead to errors in perceptual judgments and have been associated with functional declines such as increased falls risk. The objectives of this study were to determine whether passive, visual-vestibular self-motion heading perception could be improved by providing feedback during multisensory training, and whether training-related effects might be more apparent in OAs vs. younger adults (YA). We also investigated the extent to which training might transfer to improved standing-balance. OAs and YAs were passively translated and asked to judge their direction of heading relative to straight-ahead (left/right). Each participant completed three conditions: (1) vestibular-only (passive physical motion in the dark), (2) visual-only (cloud-of-dots display), and (3) bimodal (congruent vestibular and visual stimulation). Measures of heading precision and bias were obtained for each condition. Over the course of 3 days, participants were asked to make bimodal heading judgments and were provided with feedback ("correct"/"incorrect") on 900 training trials. Post-training, participants' biases, and precision in all three sensory conditions (vestibular, visual, bimodal), and their standing-balance performance, were assessed. Results demonstrated improved overall precision (i.e., reduced JNDs) in heading perception after training. Pre- vs. post-training difference scores showed that improvements in JNDs were only found in the visual-only condition. Particularly notable is that 27% of OAs initially could not discriminate their heading at all in the visual-only condition pre-training, but subsequently obtained thresholds in the visual-only condition post-training that were similar to those of the other participants. While OAs seemed to show optimal integration pre- and post-training (i.e., did not show significant differences between predicted and observed JNDs), YAs only showed optimal integration post-training. There were no significant effects of training for bimodal or vestibular-only heading estimates, nor standing-balance performance. These results indicate that it may be possible to improve unimodal (visual) heading perception using a multisensory (visual-vestibular) training paradigm. The results may also help to inform interventions targeting tasks for which effective self-motion perception is important.

Age-related changes to vestibular heave and pitch perception and associations with postural control

Falls are a common cause of injury in older adults (OAs), and age-related declines across the sensory systems are associated with increased falls risk. The vestibular system is particularly important for maintaining balance and supporting safe mobility, and aging has been associated with declines in vestibular end-organ functioning. However, few studies have examined potential age-related differences in vestibular perceptual sensitivities or their association with postural stability. Here we used an adaptive-staircase procedure to measure detection and discrimination thresholds in 19 healthy OAs and 18 healthy younger adults (YAs), by presenting participants with passive heave (linear up-and-down translations) and pitch (forward-backward tilt rotations) movements on a motion-platform in the dark. We also examined participants' postural stability under various standing-balance conditions. Associations among these postural measures and vestibular perceptual thresholds were further examined. Ultimately, OAs showed larger heave and pitch detection thresholds compared to YAs, and larger perceptual thresholds were associated with greater postural sway, but only in OAs. Overall, these results suggest that vestibular perceptual sensitivity declines with older age and that such declines are associated with poorer postural stability. Future studies could consider the potential applicability of these results in the development of screening tools for falls prevention in OAs.

Static posturographic balance in neurotologic patients may be associated with middle-high-frequency hearing levels during ageing process

BACKGROUND

Understanding how sensorineural hearing loss (SNHL) impacts postural balance in patients is important, as postural balance predicts the risk of falls.

AIMS/OBJECTIVES

We aimed to clarify the relationship between characteristics in the configuration of audiograms and static postural balance as measured by posturography.

MATERIALS AND METHODS

We evaluated 385 outpatients (mean [± standard deviation] age, 58.4 ± 18.4 years) with SNHL by audiometry and posturography. Data were analysed by multiple regression models with the outcome of postural sway area with eyes closed (PSA) and predictive variables of audiometric data, adjusted for sex, age and the presence of nystagmus.

RESULTS

The increased hearing threshold in the better hearing ear was associated with poorer or higher PSA (beta coefficient [β] = 0.39, 95% confidence interval [CI] = 0.03-0.75, per 10-dB increment). No difference in PSA was detected between patients with asymmetric or symmetric SNHL. None of the frequent diagnoses (presbyacusis, Meniere's disease, and idiopathic sudden SNHL) were associated with poorer PSA. Hearing thresholds at middle (β = 0.39, 95%CI = 0.10-0.67) and high frequencies (β = 0.31, 95%CI = 0.07-0.55) were associated with poorer PSA, whereas those at low frequencies was not.

CONCLUSIONS AND SIGNIFICANCE

Postural balance in neurotologic patients may be associated with middle-high-frequency hearing levels during ageing.

Center of pressure-based postural sway differences on parallel and single leg stance in Olympic deaf basketball and volleyball players

In sports such as basketball and volleyball, loss of balance due to the inability to maintain body stability and lack of postural control adversely affect athletic performance. Deaf athletes appear to struggle with balance and postural stability problems. The purpose of this study was to examine postural sway values in parallel and single leg stance of Olympic deaf basketball and volleyball players and reveal differences between the branches. Twenty-three male athletes from the Turkish national deaf basketball (n=11) and volleyball (n=12) teams participated in the study. After anthropometric measurements, the subjects completed postural sway (PS) tests in parallel/single leg stances with open eyes and closed eyes on a force plate. PS parameters (sway path, velocity, and area) obtained from the device software were used for the statistical analysis. The Mann-Whitney U-test was used to compare differences in PS parameters between basketball and volleyball players, and the alpha value was accepted as 0.05. Volleyball players had significantly better results in parallel stance and dominant leg PS values than basketball players (P<0.05). There was no significant difference between the groups in nondominant leg PS values (P>0.05). We think that proprioceptive and vestibular system enhancing training practices to be performed with stability exercises will be beneficial in terms of both promoting functional stability and interlimb coordination. Trainers and strength coaches should be aware of differences in the postural control mechanism of deaf athletes.

2BALANCE: Test-retest reliability of a cognitive-motor dual-task protocol

PURPOSE

Aside from typical symptoms such as dizziness and vertigo, persons with vestibular disorders often have cognitive and motor problems. These symptoms have been assessed in single-task condition. However, dual-tasks assessing cognitive-motor interference might be an added value as they reflect daily life situations better. Therefore, the 2BALANCE protocol was developed. In the current study, the test-retest reliability of this protocol was assessed.

METHODS

The 2BALANCE protocol was performed twice in 20 healthy young adults with an in-between test interval of two weeks. Two motor tasks and five different cognitive tasks were performed in single and dual-task condition. Intraclass correlation coefficients (ICC), the standard error of measurement, and the minimal detectable difference were calculated.

RESULTS

All cognitive tasks, with the exception of the mental rotation task, had favorable reliability results (0.26≤ICC≤0.91). The dynamic motor task indicated overall substantial reliability values in all conditions (0.67≤ICC≤0.98). Similar results were found for the static motor task during dual-tasking (0.50≤ICC≤0.92), but were slightly lower in single-task condition (-0.26≤ICC≤0.75).

CONCLUSIONS

The 2BALANCE protocol was overall consistent across trials. However, the mental rotation task showed lowest reliability values.

Self-Reported Sensory Impairments in Older Adults and their Association with Self-Rated Health and Mortality Outcomes

OBJECTIVES

This study assessed the relationship between self-reported impairments of vision, hearing, and dual sensory impairment, and change in self-rated health/mortality status over a 5-year period.

METHODS

Data came from the National Health and Aging Trends Study, a nationally representative survey of Medicare beneficiaries ages 65 and older. Analyses consisted of a series of ordinal logistic regressions stratified by sex.

RESULTS

For both women and men, self-reported sensory impairments were not statistical predictors of self-rated health/mortality, when other dimensions of health, such as physical functioning, participation, and activities of daily living functioning were included in models.

DISCUSSION

Understanding how self-reported sensory impairments impact self-rated health could assist in targeting rehabilitation strategies to older adults who experience sensory impairments.

Evaluating the Association Between Hearing Loss and Falls in Adults With Vestibular Dysfunction or Nonvestibular Dizziness

OBJECTIVES

Although emerging evidence suggests that hearing loss (HL) is an independent risk factor for falls, it is unclear how HL may impact falls risk in adults with vestibular dysfunction and nonvestibular dizziness. The purpose of this study was to characterize the impact of HL on falls in patients with vestibular dysfunction and nonvestibular dizziness relative to a group of patients without dizziness. In addition, this study aimed to evaluate whether there was an interactive effect between HL and vestibular dysfunction or nonvestibular dizziness on the odds of falling.

DESIGN

The authors conducted a retrospective cross-sectional study of 2,750 adult patients with dizziness evaluated at a tertiary care center vestibular clinic between June 1, 2015, and October 7, 2020. Only patients with available self-reported falls status, as extracted from the electronic medical record, were included. Patients were classified into the following diagnostic groups based on rotary chair testing and videonystagmography: benign paroxysmal positional vertigo (BPPV, n = 255), unilateral vestibular hypofunction (UVH, n = 456), bilateral vestibular hypofunction (BVH, n = 38), central dysfunction (n = 208), multiple diagnoses (n = 109), and dizzy, nonvestibular (n = 1,389). A control group of patients without dizziness (n = 295) was identified by a random sample of audiology patients. Degree of HL was characterized by the 4-frequency pure tone average (PTA) (0.5, 1, 2, and 4 kHz) of the better hearing ear. Demographic variables, comorbidities, cognitive impairment status, and falls-associated medications were extracted from the electronic medical record and included as covariates during analysis. Potential associations between PTA and falls status and possible interactions between diagnostic group and PTA were explored using multivariate logistic regression.

RESULTS

The BVH and central dysfunction groups had the highest rates of self-reported falls at 26.3% and 26.9%, respectively. The control group had the lowest rate of self-reported falls at 6.4%. With the exception of the multiple diagnoses group, all diagnostic groups had elevated odds of falling compared with the control group, when adjusting for demographics, comorbidities, cognitive impairment status, and falls-associated medications. There was no significant association between degree of HL and falls status (odds ratio [OR] = 1.02; 95% confidence interval [CI] = 0.93, 1.11; p = 0.713) when adjusting for diagnostic group and all other covariates. Furthermore, there were no significant interactions between diagnostic group and degree of HL on the odds of falling.

CONCLUSIONS

These results indicate that HL was not associated with falls in patients with vestibular dysfunction or nonvestibular dizziness, while adjusting for demographics, comorbidities, and falls-associated medications. There was no significant interactive effect observed between HL and vestibular dysfunction or nonvestibular dizziness on the odds of falling. As previously reported, vestibular dysfunction and nonvestibular dizziness were independently associated with falls relative to a group of patients without dizziness. A population-based study utilizing more robust falls data is needed to explore a potential association between HL and falls in those with vestibular dysfunction.

Potential Mechanisms of Acute Standing Balance Deficits After Concussions and Subconcussive Head Impacts: A Review

Standing balance deficits are prevalent after concussions and have also been reported after subconcussive head impacts. However, the mechanisms underlying such deficits are not fully understood. The objective of this review is to consolidate evidence linking head impact biomechanics to standing balance deficits. Mechanical energy transferred to the head during impacts may deform neural and sensory components involved in the control of standing balance. From our review of acute balance-related changes, concussions frequently resulted in increased magnitude but reduced complexity of postural sway, while subconcussive studies showed inconsistent outcomes. Although vestibular and visual symptoms are common, potential injury to these sensors and their neural pathways are often neglected in biomechanics analyses. While current evidence implies a link between tissue deformations in deep brain regions including the brainstem and common post-concussion balance-related deficits, this link has not been adequately investigated. Key limitations in current studies include inadequate balance sampling duration, varying test time points, and lack of head impact biomechanics measurements. Future investigations should also employ targeted quantitative methods to probe the sensorimotor and neural components underlying balance control. A deeper understanding of the specific injury mechanisms will inform diagnosis and management of balance deficits after concussions and subconcussive head impact exposure.

Vestibular Perceptual Thresholds in Older Adults With and Without Age-related Hearing Loss

OBJECTIVES

Older adults with age-related hearing loss (ARHL) are at greater risk of falling and have greater mobility problems than older adults with normal hearing (NH). The underlying cause of these associations remains unclear. One possible reason is that age-related declines in the vestibular system could parallel those observed in the auditory system within the same individuals. Here, we compare the sensitivity of vestibular perceptual abilities (psychophysics), vestibular end-organ functioning (vestibular evoked myogenic potentials and video head impulse tests), and standing balance (posturography) in healthy older adults with and without ARHL.

DESIGN

A total of 46 community-dwelling older adults, 23 with ARHL and 23 with NH, were passively translated in heave (up and down) and rotated in pitch (tilted forward and backward) in the dark using a motion platform. Using an adaptive staircase psychophysical procedure, participants' heave and pitch detection and discrimination thresholds were determined. In a posturography task, participants' center of pressure (COP) path length was measured as they stood on a forceplate with eyes open and closed, on firm and compliant surfaces, with and without sound suppression. Baseline motor, cognitive, and sensory functioning, including vestibular end-organ function, were measured.

RESULTS

Individuals with ARHL were less sensitive at discriminating pitch movements compared to older adults with NH. Poorer self-reported hearing abilities were also associated with poorer pitch discrimination. In addition to pitch discrimination thresholds, lower pitch detection thresholds were significantly associated with hearing loss in the low-frequency range. Less stable standing balance was significantly associated with poorer vestibular perceptual sensitivity.

DISCUSSION

These findings provide evidence for an association between ARHL and reduced vestibular perceptual sensitivity.

The Quest for Ecological Validity in Hearing Science: What It Is, Why It Matters, and How to Advance It

Ecological validity is a relatively new concept in hearing science. It has been cited as relevant with increasing frequency in publications over the past 20 years, but without any formal conceptual basis or clear motive. The sixth Eriksholm Workshop was convened to develop a deeper understanding of the concept for the purpose of applying it in hearing research in a consistent and productive manner. Inspired by relevant debate within the field of psychology, and taking into account the World Health Organization's International Classification of Functioning, Disability, and Health framework, the attendees at the workshop reached a consensus on the following definition: "In hearing science, ecological validity refers to the degree to which research findings reflect real-life hearing-related function, activity, or participation." Four broad purposes for striving for greater ecological validity in hearing research were determined: A (Understanding) better understanding the role of hearing in everyday life; B (Development) supporting the development of improved procedures and interventions; C (Assessment) facilitating improved methods for assessing and predicting ability to accomplish real-world tasks; and D (Integration and Individualization) enabling more integrated and individualized care. Discussions considered the effects of variables and phenomena commonly present in hearing-related research on the level of ecological validity of outcomes, supported by examples from a few selected outcome domains and for different types of studies. Illustrated with examples, potential strategies were offered for promoting a high level of ecological validity in a study and for how to evaluate the level of ecological validity of a study. Areas in particular that could benefit from more research to advance ecological validity in hearing science include: (1) understanding the processes of hearing and communication in everyday listening situations, and specifically the factors that make listening difficult in everyday situations; (2) developing new test paradigms that include more than one person (e.g., to encompass the interactive nature of everyday communication) and that are integrative of other factors that interact with hearing in real-life function; (3) integrating new and emerging technologies (e.g., virtual reality) with established test methods; and (4) identifying the key variables and phenomena affecting the level of ecological validity to develop verifiable ways to increase ecological validity and derive a set of benchmarks to strive for.

Hearing loss and increased gait variability among older adults

BACKGROUND

The influence of age-related hearing loss on slow gait has been suggested; however, whether it is associated with increased gait variability, an important predictor of fall risk, remains unclear.

RESEARCH QUESTION

Is poor auditory acuity associated with increased gait variability, and does this gait change relate to accidental falls among older adults with hearing loss?

METHODS

We studied 107 older adults (mean age, 76.5 years; 80.5 % women). Auditory acuity was measured using a pure tone average (PTA) of hearing thresholds for 0.5-4 kHz tones in the better-hearing ear. Hearing loss was defined as a PTA of >25 dB. Gait speed and spatiotemporal variability (i.e., stride length and time variabilities) were assessed using a 5-m electronic walkway. We also assessed the occurrence of multiple falls within the previous year.

RESULTS

Fifty-two participants (48.6 %) experienced hearing loss. Multiple regression analysis adjusted for potential covariates showed that poor PTA was associated with slower gait speed and stride length variability, but not stride time variability. Among older adults with hearing loss, fall occurrence was associated with an increased stride length variability and not a slow gait or increased stride time variability.

SIGNIFICANCE

The association between hearing loss and increased gait variability observed in the present study suggests that age-related hearing loss can jeopardize gait control during daily activities. This leads to increased gait variability and increased risk of accidental falls. Our results provide additional information on how age-related hearing loss increases the risk of falls.

Cutaneous and muscular afferents from the foot and sensory fusion processing: Physiology and pathology in neuropathies

The foot-sole cutaneous receptors (section 2), their function in stance control (sway minimisation, exploratory role) (2.1), and the modulation of their effects by gait pattern and intended behaviour (2.2) are reviewed. Experimental manipulations (anaesthesia, temperature) (2.3 and 2.4) have shown that information from foot sole has widespread influence on balance. Foot-sole stimulation (2.5) appears to be a promising approach for rehabilitation. Proprioceptive information (3) has a pre-eminent role in balance and gait. Reflex responses to balance perturbations are produced by both leg and foot muscle stretch (3.1) and show complex interactions with skin input at both spinal and supra-spinal levels (3.2), where sensory feedback is modulated by posture, locomotion and vision. Other muscles, notably of neck and trunk, contribute to kinaesthesia and sense of orientation in space (3.3). The effects of age-related decline of afferent input are variable under different foot-contact and visual conditions (3.4). Muscle force diminishes with age and sarcopenia, affecting intrinsic foot muscles relaying relevant feedback (3.5). In neuropathy (4), reduction in cutaneous sensation accompanies the diminished density of viable receptors (4.1). Loss of foot-sole input goes along with large-fibre dysfunction in intrinsic foot muscles. Diabetic patients have an elevated risk of falling, and vision and vestibular compensation strategies may be inadequate (4.2). From Charcot-Marie-Tooth 1A disease (4.3) we have become aware of the role of spindle group II fibres and of the anatomical feet conditions in balance control. Lastly (5) we touch on the effects of nerve stimulation onto cortical and spinal excitability, which may participate in plasticity processes, and on exercise interventions to reduce the impact of neuropathy.

Impact of the sensory environment on balance in children with bilateral cochleovestibular loss

BACKGROUND

The aim of the present study was to determine the role of auditory and visual sensory input on balance in children with bilateral cochlevestibular loss. The prevalence of vestibular impairment, and specifically bilateral vestibular loss (BVL) in children with sensorineural hearing loss (SNHL) is high and children with profound cochleovestibular loss (SNHL-BVL) have impaired balance (Suarez et al., 2007; Suarez et al., 2019). Given that both hearing and vestibular impairments are often congenital or acquired in early life, it remains difficult to tease out the individual developmental impact of either one on balance and spatial awareness in children who experience both of these sensory deficits. While cochlear implants (CI) can provide or restore access to sound in children with SNHL-BVL, there is currently no vestibular prosthetic available for clinical use in this population. These children may also use their intact sensory inputs (i.e. vision) to a greater extent to support balance. Alternately, restoring or providing access to sound may, on its own, help these children to balance better. We hypothesized that balance in children with SNHL-BVL who use bilateral CIs is: 1) improved in the presence of directional sound and 2) impaired when visual cues are dynamic (moving) rather than static.

METHODS

Balance was assessed in 18 children with SNHL-BVL and 34 typically developing children with intact vestibular function and normal hearing by performing the Bruininks-Oseretsky Test of Motor Proficiency-2 (BOT-2) balance subtest in a virtual-reality simulator under 4 sensory conditions of graded complexity. Randomized conditions combined 2 auditory (moving directional street sounds vs. directionless static white noise) and 2 visual (dynamic street scene vs. stationary street scene) stimuli designed to recreate a "real-world" busy downtown street. Balance ability in children with SNHL-BVL was also compared with CI on and off.

RESULTS

As expected and similar to previous work, balance was significantly worse in the children with SNHL-BVL compared to typically developing children in all sensory conditions (p<0.0001). As a group, the mean balance skills of the children with SNHL-BVL were equivalent to that of a 4.4-year-old child despite being much older (mean age =13.8 years). Balance ability improved slightly but significantly when children with SNHL-BVL had access to any sound through their CI (p=0.047) and was positively correlated with duration of implant use (p=0.02). Balance ability did not change further in the presence of moving directional sounds compared to static white noise (p=0.42), or when coupled to a moving visual environment (p=0.32) in children with SNHL-BVL, however opposite to what was hypothesized, in the typically developing group, there was a decrement in performance that occurred in the presence of moving directional sound compared to directionless, static white noise (p=0.02).

CONCLUSIONS

Balance ability in children with SNHL-BVL who use bilateral CI was, as expected, poorer than their typically developing peers in all sensory conditions but improved slightly when they had access to any sound through their implants, with this benefit increasing as duration of implant use increased. This suggests that providing sound inputs through bilateral CIs positively affects balance in children with SNHL-BVL where vestibular and/or auditory inputs are compromised. This benefit was achieved even with auditory inputs that were devoid of moving directional cues (i.e. directionless static white noise) and is consistent with poor spatial hearing in children using bilateral CI.