Pou4f3 promoter. Due to higher Pou4f3 expression in cochlear hair cells than vestibular hair cells, administration of a low dose of DT caused profound SNHL without vestibular dysfunction and had no effect on wild-type (WT) littermates. Spatial learning/memory was assayed using an automated radial 8-arm maze (RAM), where mice were trained to find food rewards over a 14-day period. The number of working memory errors (WME) and reference memory errors (RME) per training day were recorded. All animals were injected with DT during P30–60 and underwent the RAM assay during P90–120. SNHL animals committed more WME and RME than WT animals, demonstrating that isolated SNHL affected cognitive function. Duration of SNHL (60 versus 90 days post DT injection) had no effect on RAM performance. However, younger age of acquired SNHL (DT on P30 versus P60) was associated with fewer WME. This describes the previously undocumented effect of isolated SNHL on cognitive processes that do not directly rely on auditory sensory input.Current clinical interest lies in the relationship between hearing loss and cognitive impairment. Previous work demonstrated that noise exposure, a common cause of sensorineural hearing loss (SNHL), leads to cognitive impairments in mice. However, in noise-induced models, it is difficult to distinguish the effects of noise trauma from subsequent SNHL on central processes. Here, we use cochlear hair cell ablation to isolate the effects of SNHL. Cochlear hair cells were conditionally and selectively ablated in mature, transgenic mice where the human diphtheria toxin (DT) receptor was expressed behind the hair-cell specific  This association is commonly seen in the elderly, who experience a wide clinical spectrum of hearing and cognitive impairments. While this association is likely modulated in part by common aging processes that affect both hearing and cognition4, current clinical interest lies in whether peripheral hearing loss can induce or accelerate cognitive decline. The cause-and-effect relationship between hearing loss and cognitive decline is plausible due to the dynamic interaction between auditory and cognitive processing. Sensory information processing is a fundamental component of learning, memory, and cognition6, and brain structures responsible for encoding spatial representations can use visual, olfactory, and auditory information to generate memories of navigable space9. Progressive hearing loss is correlated with widespread changes in neurotransmitter expression that potentiate spatial memory impairments11. These associations suggest there exists a causal mechanism underlying hearing-related cognitive decline. Determining the causal mechanism would be important to inform whether cognitive decline could be prevented or managed by early auditory interventions.Auditory sensory loss is associated with cognitive decline14. However, noise exposure also directly causes cognitive deficits by oxidative stress along both the peripheral and central auditory pathways16. Therefore, distinguishing the indirect cognitive effects of the subsequent hearing loss from the direct effects of oxidative stress is difficult in the noise induced model.To begin understanding the causal mechanisms by which hearing loss and cognitive decline are linked, it is important to study how the brain functionally adjusts to the initial loss of auditory input. Noise-induced hearing loss is a common form of acquired hearing loss and is easily induced experimentally. Animals with hearing loss following noise exposure experience decreased hippocampal cell proliferation and synapse formation that correlate with spatial memory impairmentHere, a transgenic mouse line where hearing loss can be induced through selective cochlear hair cell ablation is used to assess the initial cognitive consequences of hearing loss. We show here that sudden loss of function at the auditory periphery causes a spatial learning and memory impairment. The severity of the impairment persists beyond 2 months of the auditory insult. Mice that lost hearing at an older age (2 months) demonstrated a more severe spatial memory deficit than mice that lost hearing at a younger age (1 month), suggesting that cognitive impairment due to hearing loss may be more severe with advanced age of hearing loss onset. Taken together, this data indicates that sudden hearing loss is accompanied by spatial learning and memory impairment, demonstrating that hearing loss is causally linked to cognitive impairment.B6.Cg-Pou4f3tm1.1(HBEGF)Jsto/RubelJ mice , which expressed the human diphtheria toxin receptor (DTR) behind Pou4f3, a transcription factor expressed specifically by hair cells in the inner ear17. Since mice are resistant to diphtheria toxin (DT), expression of the human DTR gene in hair cells allowed for selective hair cell ablation upon systemic DT administration. DTR transgenic animals experienced rapid hearing loss after DT injection while wild-type (WT) littermates did not. Hearing was assessed by auditory brainstem response (ABR) thresholds  of the apex, middle, and base of the cochleae Fig. d. Cells 19. A small dose of DT (6.25 ng/g) caused rapid cochlear hair cell loss but did not cause vestibulomotor dysfunction phenotypes such as head-bobbing, staggering gait, circling or rolling behavior at any point after DT injection.While ablation of cochlear hair cells induced hearing loss, it was important to spare vestibular hair cells so that the effect of hearing loss on spatial learning and memory would not be confounded by vestibular deficits. As previously demonstrated, the ablation of vestibular hair cells required a much higher dose of DT than cochlear hair cells in DTR animals21. Furthermore, when comparing movement metrics between WT and DTR, there was no significant difference in mean movement velocity  and subjective assessment of gait on visual and center-point video tracking analysis revealed no apparent differences between groups.Long term vestibular function was objectively assessed using VsEPs Fig. a, histolPou4f3 is expressed in small subset of retinal ganglion cells (RGCs) and transgenic deletion of Pou4f3 caused hearing and vestibular defects but no retinal defects25. It has been previously suggested that DT would not be lethal to RGCs in mature DTR animals26. Further considering that the dose response allowed for vestibular sparing despite Pou4f3 expression in 100% of vestibular hair cells, we hypothesized that the current dose would spare RGCs. To experimentally confirm retinal exclusion, mature mice (P30) were injected with 6.25 ng/g DT and retinas were harvested at 2 and 10 dpi. RGC counts were obtained in an automated fashion along a 210 μm section of the RGC layer  expressed centrally in mature animals to our knowledge. To experimentally confirm central exclusion, mature mice (P30) were injected with 6.25 ng/g DT and brains were harvested at 2 and 10 dpi. Striatal cells were counted in an automated fashion in 420 μm2 sections . On the last day of habituation (training day − 1), the difference in group performance approached statistical significance . When the RAM paradigm was changed from habituation to testing, WMEs increased in all groups as expected. However, the difference in WMEs between groups at the beginning of the testing period on day 1 was not significantly different . When longitudinal performance was statistically compared during the testing period, DTR animals had significantly worse performance than WT animals .The first experiment determined whether cochlear hair cell ablation caused a measurable difference in spatial learning/memory. DTR and WT animals were injected during P30-P60 and RAM training began during P90-P120. For working memory, DTR animals performed worse during habituation longitudinally . These data demonstrate that lesions isolated to the auditory periphery cause impairment of central processes that do not directly rely on auditory sensory input.For reference memory, DTR animals performed worse than WT animals longitudinally during the testing period . By the end of the testing period on training day 10, DTR animals committed more errors than WT animals  were divided into two groups based on age at RAM training start (P90 and P120), which represented different durations of hearing loss . WT animals were also divided into groups that were age-matched with the DTR groups with respect to age at RAM training start (P90 and P120).For working memory Fig. a, there Similar associations were observed for reference memory Fig. a. There To assess whether age at onset of hearing loss affected spatial learning and memory, performance of an additional group of DTR animals that received DT injection at a younger age (P30) and began RAM training at 60 dpi (DTR-P30 DT). Since performance was statistically similar between DTR groups injected at P60 and tested at 30 or 60 dpi for both WME  and RME , data from these groups were pooled for analysis (DTR-P60 DT). For the same reason, data from WT groups injected at P30 or P60 and tested at 60 dpi were pooled for analysis .–5) and during testing . When comparing the DTR groups, there was no difference in performance during habituation , however, the DTR-P60 DT group performed significantly worse than the DTR-P30 DT group during testing , suggesting that age at hearing loss onset may affect working memory.For working memory Fig. b, longit–4 for DTR-P30 DT and F = 35.39, p = 8.71 × 10–7 for DTR-P60 DT). However, there was no difference in performance observed between DTR groups . These data suggest that age of acquired hearing loss affects the degree of central deficit and that younger age is associated with attenuated deficit. Since neural plasticity is greater at younger ages, it is likely that increased plasticity compensates for the loss of auditory sensory input.For reference memory Fig. b, the DTThe results of this study show that isolated sensorineural hearing loss produced via selective cochlear hair cell ablation causes spatial memory impairments. The duration of hearing loss had no impact on the degree of memory impairment in the timelines studied; mice that experienced 1 month of hearing loss demonstrated similar memory deficits to mice that experienced 2 months of hearing loss. However, the age of hearing loss onset affected the degree of memory impairment; mice that lost hearing at P60 had worse memory than mice that lost hearing at P30. These data suggest that the sudden hearing loss compromises cognitive function and this effect may be modulated by the age of hearing loss onset. This finding offers novel insights into the putative pathway by which hearing loss causes cognitive decline in humans.29. Calls at 22 kHz are associated with threats while calls at 50 kHz are associated with rewards30. Mouse pups produce isolation vocalizations in the 50–200 kHz range31 and reproductive vocalizations in adult mice are recorded at intensities over 100 dB SPL at 40 kHz32. Taken together, hearing is an important sensory modality in mice for interpretation of social behaviors, thus making it plausible that acquired hearing loss could have central consequences in mice.Rodents rely heavily on auditory information in the form of vocalization for and social integration and establishment of social structures . These vocalizations are predominantly ultrasonic (> 20 kHz); while human hearing typically extends from 0.02 to 20 kHz with fine tuning to speech frequencies (0.08 to 2 kHz), rodents hear sounds ranging from 0.2 to 90 kHz11. This is consistent with human neuroimaging data that demonstrates that age-related hearing loss is associated with decreased brain volume35. The hippocampus receives direct input from the auditory cortex37, which facilitates memory formation and consequently guides behavior40, so it is conceivable that global cognitive function may be affected by auditory deprivation. However, hearing loss experienced in aging is cumulative in nature and its global consequences may be confounded by other effects of age. Studying rapid-onset hearing loss would therefore be informative in this regard. Prior studies where rapid-onset hearing loss was induced relied on noise as a damage model and found that noise-induced hearing loss (NIHL) caused impairments to spatial working and reference memory14. However, permanent NIHL requires noise exposure of over 120 dB SPL for several hours. This degree of noise exposure may cause profound stress on central pathways, leading to cognitive and emotional consequences that in turn may affect performance on behavioral assays. Distinguishing the effects of the noise exposure itself from subsequent NIHL is challenging for several reasons. First, the adverse impact of noise on learning and memory has consistently been reported previously44. Second, impulse noise exposure itself causes long term central effects even in the absence of permanent NIHL45. Therefore, assessing the effects of peripheral sensory loss requires a model where conditional hearing loss could be induced in adulthood with no or minimal central stress.Prior data in mice has demonstrated that the degree of age-related hearing loss characteristic of the C57BL/6 strain closely correlates to the decrease in spatial memory performance and hippocampal plasticity17. Use of a very low dose of DT caused damage that correlated with the degree of Pou4f3 expression; there was near complete inner hair cell damage that caused profound hearing loss, minor utricle hair cell loss that was not physiologically detectable, and negligible central loss. Therefore, the dominant insult in this model was sensorineural hearing loss due to inner hair cell ablation. Here, we find that sudden sensorineural hearing loss causes a spatial memory and learning deficit.Here we used a transgenic mouse model that allowed for conditional and selective cochlear hair cell ablation by insertion of the human DTR gene after the Pou4f3 promoter. This promoter is robustly expressed in inner hair cells with lower expression in outer and vestibular hair cells and minimal expression in the central nervous systemIn the current study, age of hearing loss onset affected the severity of the cognitive impairment. The cohort that experienced hearing loss at P60 had more severe working memory impairment than the P30 cohort. Since working memory and neural plasticity both decrease with age, it is possible this modulates the effect that age of hearing loss has on memory. Mice at P30 may have less developed dependency on hearing and consequently a lower barrier to adapt to hearing loss. Alternatively, the P30 brain may be inherently more plastic than the P60 brain and is therefore better able to adapt to sensory loss. It is likely that a combination of these possibilities is at play. Since selective cochlear hair cell ablation in perinatal mice could not be consistently achieved with the current model, future investigation into the effect of congenital versus acquired hearing loss on cognition would be informative. This effect was not observed for reference memory; however, it is likely that this was influenced by the limited resolution of the reference memory assay.14. Since hearing loss is permanent in cochlear hair cell ablation, it is possible that the cognitive deficit may be alleviated by hearing restoration. Alternatively, it is possible that the current study period falls within the transitional phase following hearing loss, as the mammalian brain is adaptable to other forms of sensory loss. Specifically, visual loss similarly causes cortical and subcortical reorganization that hinders cognitive performance46. However, long-term cognitive recovery following perpetual visual loss occurs49, suggesting that long-term recovery following hearing loss may also occur beyond the observation period.Finally, the duration of hearing loss did not affect the degree of cognitive impairment up to 2 months after onset. It is possible that in sudden hearing loss, the maximal cognitive effect is rapidly reached and persists for the duration of hearing loss. This is consistent with prior data suggesting that partial hearing recovery occurring 12 months after noise-induced hearing loss is accompanied by partial recovery of spatial working memory but not reference memoryIn conclusion, this work demonstrates that spatial learning and memory impairment follows mature-onset cochlear hair cell ablation in mice, suggesting that sensorineural hearing loss causes a cognitive impairment. It is likely that hearing loss has a similar effect on human cognition and behavior given the strong association observed between hearing loss and cognitive decline. It would be of interest to know whether hearing loss onset before the critical period would have a similar effect on behavior, whether long term recovery occurs, or if this effect could be mitigated by auditory rehabilitation. Additionally, this experimental approach provides the opportunity to investigate the neuroanatomical networks and neurotransmissions involved and influenced by cognitive decline due to hearing loss.B6.Cg-Pou4f3tm1.1(HBEGF)Jsto/RubelJ transgenic mouse line . The generation and characterization of these mice were previously described19. In brief, this transgenic line was generated on a C56BL/6 J background and expressed the gene for human diphtheria toxin receptor  under the regulation of the Pou4f3 promoter. The gene product of the Pou4f3 promoter (Brn3c) is ubiquitously expressed during development but expression in mature animals is limited to cochlear hair cells, vestibular hair cells, and a small subset of retinal ganglion cells (RGCs)50. While there have been reports of Pou4f3 mRNA expressed in the striatum and olivary nuclei17, there have been no prior reports of the Brn3c expression in the mature brain to our knowledge. Prior work has shown that ablation is dose sensitive17, and that low expression of Pou4f3 in off-target tissues such as RCGs allow for off-target exclusion26. Additionally, the lack of central Brn3c expression in mature animals would suggest that the central nervous system is also spared in this model.All experimental procedures were performed on the Pou4f3 expression (i.e. cochlear hair cells) while having no effects on wildtype (WT) littermates. Ablation of vestibular hair cells in DTR mice required a much higher dose of DT than cochlear hair cells19, thus a single intraperitoneal injection of low dose (6.25 ng/g) DT  at P30 or P60 was chosen to cause hearing loss without apparent vestibulomotor dysfunction. The low dose was then experimentally confirmed to spare RGC and striatal cells. Genotypes were established using PCR as described previously51. Animals from both sexes were used. All procedures were approved by the Animal Care and Use Committee at Stanford University. All methods were carried out in accordance with relevant guidelines and regulations.Systemic treatment of adult, heterozygous DTR mice with a low dose of diphtheria toxin (DT) resulted in specific ablation of cells with high 52. In brief, mice were anesthetized with an intraperitoneal injection of 10 mg/kg ketamine and 10 mg/kg xylazine and placed on a thermostatic heating pad to maintain body temperature between 37.5–38 °C. ABRs were recorded from a needle electrode placed inferior to the tympanic bulla and referenced to an electrode on the cranial vertex, with a ground electrode placed into the ipsilateral hindlimb. Tone pip stimuli  were presented from an open-field speaker in 10 decibel sound pressure level (dB SPL) steps up from 0 to 90 dB SPL in frequencies ranging from 5.7 to 32 kHz. Waveforms for each condition were generated by averaging 256 responses. ABR thresholds for each frequency were defined as the intensity at which the typical peak I could be identified. A lack of response was designated at the highest sound level, 90 dB SPL.Auditory brainstem responses (ABRs) were measured as previously described53. Mice were anesthetized (10 mg/kg ketamine and 10 mg/kg xylazine) and had electrodes placed in an identical manner as described for ABRs. The head was clipped to a mechanical shaker, which delivered linear jerk stimuli in the naso-occipital axis ranging from 0.125 to 2.0 g/ms. Broadband noise from an open-field speaker (90 dB SPL) was used to mask responses from the auditory components of cranial nerve VIII. Responses from normal and inverted vestibular stimulus polarities were summed for 256 sweeps per waveform. VsEP thresholds were defined as the intensity at which a typical positive response peak I could be identified.Linear vestibular evoked potentials (VsEP) responses were recorded as previously described54. Turns were triple-washed in PBS with 0.5% triton (PBST) then incubated for 1 h in blocking solution , overnight at 4 °C in rabbit anti-myosin 7a , then for 1.5 h in Alexa Fluor donkey anti-rabbit 546  and DAPI .Mice were anesthetized as previously described and were then perfused via the intracardiac route with 25 mL of 4% paraformaldehyde (PFA). Cochleae, eyes, and brains were then immediately dissected. Cochleae were perfused with 0.5 mL of PFA via the intralabyrinthine route through openings made in the round and oval windows, immersed in PFA for 45 min, decalcified in 1 M EDTA for 3 days at 4 °C, and finally dissected into 3 turnsEyes were immersed in PFA for 15 min, then 30% sucrose in PBS overnight at 4 °C, embedded in optimal cutting temperature (OCT) compound , then cryosectioned along the transverse axis in 40 μm-thick sections onto slides. Slides were then stained with hematoxylin and eosin  or DAPI.Brains were immersed in PFA overnight, then 30% sucrose in PBS for 48 h at 4 °C, embedded in OCT, then cryosectioned along the antero-posterior axis in 40 μm-thick sections into wells of PBS. Free floating sections were then triple-washed in PBST, incubated for 1 h in blocking solution, 2 h in rabbit anti-NeuN , then 1.5 h in Alexa Fluor donkey anti-rabbit 546 and DAPI.All tissues were imaged as Z-stacks on a Zeiss LSM700 confocal microscope. Images were captured using Zen Black software (Zeiss) and analyzed with Zen Blue software (Zeiss) and ImageJ (NIH) or Imaris (Oxford Instruments).Cochlear hair cells were counted along 200 μm sections along the contour of the tunnel of Corti. Cells with DAPI-stained nuclei associated with myosin 7a-stained cell bodies were counted. Counts were statistically compared between groups using one-way ANOVAs. Vestibular hair cells were counted in 130 μm × 130 μm sections of the utricle. Cells with Phalloidin-stained bundles were counted in a striolar and an extra-striolar section and averaged for each utricle. Counts were statistically compared using t-tests.For RGCs, nuclei in the RGC layer were counted along 210 μm sections along the contour of the inner limiting membrane. Counts were performed in an automated fashion using spot detection in Imaris. The automatic threshold at which spots were inserted in the RGC layer was manually adjusted on a representative image, the parameters saved, then batch applied across all retinal sections for objective counts relative to the reference image. For each eye, the RGC count was the average of six evenly spaced sections along the transverse axis. Counts were statistically compared between groups using one-way ANOVAs.Striatal cells were counted in 420 μm × 420 μm sections. Counts were performed in an automated fashion using spot detection in Imaris. Automatic thresholds at which spots were inserted in the field of view were manually adjusted on a representative image separately for NeuN and DAPI channels, the parameters saved, then batch applied across all striatal sections for objective counts relative to the reference image for each channel. For each hemisphere, the striatal cell count was the average of eight equally spaced, atlas matched (Allen Mouse Brain Atlas) sections across the antero-posterior axis. Counts were statistically compared between groups using one-way ANOVAs.56. All procedures were performed during the light cycle.Animals were housed in standard tub cages in groups of 3–4 littermates of identical sex, genotype, and DT injection status prior to experiments. All cages were enriched with corn cob bedding, paper nesting material, and paper tubes equal in number to the animals in each cage. Animals were allowed access to regular feed and water ad libitum and maintained on a 12:12 light cycle (6 am to 6 pm light). Animals were transitioned to individual housing and feed consisted of pellets of identical size and weight  approximately one week prior to experiments. During this time, animals were reduced to 85%-90% of their free-feeding weight through feed restriction and acclimated to transport in their home cages and to experimenter handling via a non-aversive tunnel handling techniqueSpatial learning/memory was assayed using an automated 8 arm radial maze Fig. b, which At the beginning of each trial, mice were placed in a RAM and restricted to the central hub to promote spatial orientation. Once all 8 octants of the central hub were explored and 30 s had elapsed, all doors opened to allow free exploration of the maze. During habituation, single feed pellets served as bait were placed in goal zones located at the terminal ends of each arm  and testing (10 days) phases Fig. c. DuringScoring was performed in an automated fashion using video tracking software. An entry was defined as the first nose poke into a goal zone for a given arm entry Fig. b. Workin27. Results for nparLD analyses were reported as modified ANOVA-type statistics accounting for whole-plot factors.Statistical analyses were performed using R software . Measures of auditory damage were compared between groups using two-way ANOVAs or t-tests. Since behavioral data was nonparametric due to scoring ceilings and floors, group performance on specific days were compared using Kruskal–Wallis tests and while longitudinal performance between groups were compared using compared using the nparLD  packageSupplementary Video 1.Supplementary Information 1.


Significance: Selective retina therapy (SRT) selectively targets the retinal pigment epithelium (RPE) and reduces negative side effects by avoiding thermal damages of the adjacent photoreceptors, the neural retina, and the choroid. However, the selection of proper laser energy for the SRT is challenging because of ophthalmoscopically invisible lesions in the RPE and different melanin concentrations among patients or even regions within an eye.Aim: We propose and demonstrate SRT monitoring based on speckle variance optical coherence tomography (svOCT) for dosimetry control.Approach: M-scans, time-resolved sequence of A-scans, of ex vivo bovine retina irradiated by Results: SvOCT images show abrupt speckle variance changes when the retina is irradiated by laser pulses. The svOCT intensities averaged in RPE and photoreceptor layers along the axial direction show sharp peaks corresponding to each laser pulse, and the peak values were proportional to the laser pulse energy. The calculated temperatures in the neural retina layer and RPE were linearly fitted to the svOCT peak values, and the temperature of each lesion was estimated based on the fitting. The estimated temperatures matched well with previously reported results.Conclusion: We found a reliable correlation between the svOCT peak values and the degree of retinal lesion formation, which can be used for selecting proper laser energy during SRT. SvOCT images corresponding to various laser pulse energies and the various number of frames were obtained. The svOCT values of RPE and photoreceptor layers were averaged along the axial direction, and peak values of the svOCT at each pulse laser irradiation were analyzed. The microscopic images of the treated spots were taken before and after removing the upper neural retinal layers to assess the degree of retina and RPE damage. Spatial and temporal thermal effects in retina induced by pulse laser irradiation were simulated and correlated to the peak values of svOCT.Speckle variance OCT (svOCT) quantifies the speckle pattern variation caused by moving particles or structural changes in biological tissues. It calculates the interframe intensity variance of a sequence of structural OCT images. The svOCT has been extensively developed in recent years for OCT angiography, which is used to visualize retinal microvasculatures;2ex vivo bovine eyes were acquired from a local butcher and immersed in a cooled saline solution. Bovine eyes have tapetum fibrosum, which has the retinal epithelial layer completely unpigmented, over the central and mid-region of the retina.An in-house built swept-source OCT imaging system was integrated with a frequency-doubled Nd:YLF laser-based SRT system . The schematic of the system is shown in SvOCT images were calculated by ,Spatial and temporal temperature distributions in the retina were numerically calculated by COMSOL Multiphysics software. Spatial distribution was calculated in 2-D, and the geometry of the bovine retina model used for the simulation is shown in The temperature of the neural retina was calculated by averaging the temperature in a rectangular region (3To find appropriate Average peak values of svOCT depend on the laser pulse energy; the result is summarized in In addition, the average peak value of svOCT intensities was correlated to the simulated temperature of the neural retina and melanosome surface in RPE. The linear regression of average peak values of svOCT on laser energy was calculated for photocoagulated lesions and selectively damaged lesions. Then, each of them was correlated to the simulated temperature of neural retina and RPE because the tissue damage process was different from each other. Since the simulated temperature of melanosome surface in the RPE was also linear to pulse laser energy, it was correlated to the average peak values of selectively damaged lesions as We also simulated temperatures of the neural retina and the melanosome surface in RPE as a function of laser energy level for three pulse durations—2, 5, and 4ex vivo bovine eyes; the svOCT showed distinctive signal variation corresponding to each laser pulse irradiation. The signal variations were proportional to pulse energy levels, and it had a reliable correlation with the creation of lesion within the retina. The temperature at the neural retina and RPE was estimated by svOCT peak values using temperature simulation results, which was consistent with the observed lesion creation. However, we could have missed some minor tissue damages when assessing the photocoagulation and RPE cell damage from the microscopic images. Therefore, more studies that incorporate further analysis supported by histology or fluorescence microscopy would be needed to obtain a more accurate correlation between the svOCT signal and retinal damage range. In addition, we plan to perform in vivo studies using a live animal model to fully validate the utility of this method as an automatic dosimetry control in clinical SRT systems.It was shown that the SRT could be successfully monitored by the svOCT imaging system when integrated with the SRT system. We tested our system performance using


I2 was also used to check for heterogeneity. To test for publication bias, funnel plots were drawn using Egger’s regression. Based on the inclusion criteria, 16 studies were divided into two groups to identify short-term hearing changes (n = 7) and long-term hearing changes (n = 9). In the short term, there was no significant immediate change in the thresholds or amplitudes after the music exposure, although pure-tone thresholds (PTAs) and distortion product otoacoustic emissions (DPOAEs) did show the highest effect size  and  at 4 kHz. On the other hand, for long-term hearing changes, the PTA provided the highest effect size at 6 kHz  and 8 kHz , while also implying that habitual and repeated personal listening device (PLD) usage can act on some significant hearing changes in audiological tests. We conclude that the use of a PLD produces a few temporary hearing changes at 4 kHz after its use but that the changes are then reversed. However, it is important to note heavy PLD users’ experience regarding permanent changes in their hearing thresholds at high frequencies, and the public should be educated on this issue.The present study explores the scientific evidence on whether music exposure temporarily or permanently affects hearing sensitivity in young adults. Six electronic databases were searched using related keywords for the four categories of personal listening devices, listening habits, hearing outcomes, and age. The Hedges’ g and its 95% confidence intervals (CIs) were estimated. A Higgins  Excessive noise exposure, which usually causes damage to the ear’s hair cells, is considered a major cause of hearing disorders worldwide . AccordiPLDs have become increasingly popular over the last two decades, and their form has changed from a portable CD player, MP3 player, or iPod  to a mobNotably, potentially substantial evidence in the literature shows an increasing potential risk from excessive music exposure to young adults’ listening to their music using PLDs ,5. In adIn summary, it is worth exploring the existing evidence to compare between temporary (short-term) and permanent (long-term) hearing changes; by doing so, we can better understand the different aspects of young adults’ hearing changes resulting from excessive music exposure to achieve better public health. Moreover, it is important to characterize the early identification of excessive music exposure on hearing, if any, using a combination of tools that can detect hearing damage at the initial subclinical stage. In this light, the purpose of the present review and meta-analysis is to review new and timely literature for a comparison of the short-term and long-term hearing changes in young PLD users who use these devices often and heavily.To provide transparency in the systematic search and selection, the present study followed the methodology and protocols of the preferred reporting items for the Systematic reviews and meta-analyses (PRISMA) statement  and InteTo identify articles for inclusion, six electronic databases ) were searched in October 2019 using the key terms listed in All inclusion criteria were consistent in terms of the participants, intervention, control, outcomes, and study design (PICOS) strategy . The PICBased on combinations of the key terms in different databases see , the artTo assess the quality of the selected studies, the Newcastle–Ottawa scale (NOS) for cohort study  was usedp < 0.05 significance set. The heterogeneity between the studies was calculated as the 2I. The degree of heterogeneity was set at low (2I <40%), medium (40% < 2I <60%), and high (60% < 2I) levels. A randomized model was applied to estimate the combined effect. To determine the source of any heterogeneity, a meta-regression analysis was also performed. For additional insight, subgroup analyses were performed based on the PLLs and exposure times. Any small study effects were explored using funnel plots and Egger’s regression.In the present study, a statistical software program for meta-analysis, Comprehensive meta-analysis,  was used. After the selected studies were divided according to the designated study design, a meta-analysis was carried out to compare changes in the effect size for both hearing thresholds of pure-tone audiometry (PTA) and amplitude of otoacoustic emissions (OAEs) for the experimental and control groups, for both short-term and long-term hearing changes. For each meta-analysis, the effect size was calculated as Hedges’ g, along with the 95% confidence interval (CI) with a Using the search strategy, 2505 records were identified in the six electronic databases. After removing 477 duplicates, 1859 articles were removed based on the exclusion criteria, such as not being peer-reviewed, not an academic article, or irrelevant topic. A total of 169 remaining articles that were potentially relevant were screened by carefully reading their titles and abstracts. Using this process, 152 articles were excluded due to noncompliance with PICOS criteria and 17 articles were included. In Sixteen studies were included in the systematic review and meta-analysis. These studies were cohort studies or cross-sectional studies and investigated the hearing thresholds in young adults. More specifically, the 16 studies were divided into two groups: temporary  hearing changes and permanent (or long-term) hearing changes.n = 7) assessed the change in thresholds of PTA or amplitude of distortion product otoacoustic emissions (DPOAEs) of pre- and post-music exposure. The studies related to long-term hearing changes (n = 9) compared the PTA and DPOAE test outcomes of the PLD user group and nonuser group, as divided by questionnaires or interviews. Additionally, both exposure intensity and time (or duration) of PLD use were checked. Each study is summarized in The studies with short-term hearing changes (n = 7) [n = 9) [Sixteen high-quality studies that reported hearing thresholds of PTA  and amplitudes of the DPOAEs  were pooled for analysis. As mentioned earlier, the studies were divided into two groups to see short-term hearing changes  ,28,29,32 [n = 9) ,31,33,34p 0.078), while the distribution of the 4 kHz thresholds showed the highest heterogeneity (2I 74.90%). Interestingly, the thresholds at 6 and 8 kHz showed different aspects of effect size. The effect sizes of 6 and 8 kHz thresholds appeared relatively smaller; 6 kHz, −0.059, CI −0.438 to 0.320; p 0.760 and 8 kHz, −0.066, CI −0.436 to 0.303; p 0.725. Moreover, the 6 and 8 kHz thresholds showed low heterogeneity (less than 5% of 2I). Regardless of the test frequencies, however, the overall effect size of the PTA thresholds showed –0.154  with medium heterogeneity (2I 42.92%). These results did not indicate any significant deterioration of the hearing thresholds after music exposure.For short-term hearing changes within 24 h after music exposure ,28,29,32p 0.155) , the amplitude at 2 kHz was relatively less affected . The overall effect size of the DPOAEs was 0.089 , indicating no significant amplitude change within 24 h after music exposure. In sum, the short-term result after music exposure did not show any meaningful changes for PTA thresholds or DPOAE amplitudes.Similar to PTA outputs, the amplitude of DPOAEs showed the largest effect size also at 4 kHz  see . The hetTo identify the long-term hearing changes after music exposure ,31,33,34p 0.006), although the data for 6 kHz showed the highest heterogeneity (2I 80.09%). The 8 kHz also had a –0.486 significant effect size  with medium heterogeneity (2I 57.62%). Unlike the short-term hearing changes, however, the thresholds for 4 kHz showed the lowest effect sizes  and heterogeneity (2I 38.63%). Overall, the long-term hearing changes determined by PTA measurement showed a −0.419 effect size (CI −0.632 to −0.207) with significance (p 0.000), indicating that consistent PLD usage significantly and negatively affects the user’s hearing thresholds in the long term.In the PTA testing, the highest effect size was at 6 kHz  and significant (p 0.311) and 4 kHz  with medium (2I 58.77%), and high (2I 76.65%) heterogeneity, respectively. However, the long-term effects of music exposure on DPOAEs showed an overall 0.115 effect size (CI 0.037 to 0.266) with no significance (p 0.138). In short, analysis of the long-term changes showed a significant negative effect for the user’s hearing thresholds, especially at 6 and 8 kHz of PTA, but no remarkable effect to the amplitude of DPOAEs.With the DPOAEs, the highest effect size was at 2 kHz .In addition, the four funnel plots that related to the results of PTA thresholds and DPOAEs amplitude showed no publication bias see  with no The present review focused on: (1) exploring the existing evidence for a comparison between the short-term and long-term hearing change that occurs from the music exposure, and (2) characterizing these aspects of changed hearing status for early identification and intervention. Thus, the present study examined PLD users’ hearing status via the most sensitive clinical tests, such as PTA and DPOAE, and elucidated a possible association with the exposure to music. Similar to the present study, the World Health Organization (WHO) reported guidelines for leisure noise with regulation of the exposure intensity and time, health outcomes, and interventions . In its Seven articles indicating pre- and post-experimental study were categorized as short-term hearing changes ,28,29,32In terms of PTA thresholds, three of the five studies reported no statistically significant change in hearing thresholds after the music exposure ,25,29, wLAeq,1h, Keppler, and Bockstael reported 92.41 dB LAeq,1h at 1 h [LAeq,1h at 1 h [LAeq, 1 h) [When focusing on exposure intensity and time, in four studies ,23,25,32h at 1 h . Consideeq, 1 h) ,10, thesIn the analysis of long-term hearing changes, nine studies using either a case-control study or a cross-sectional study were grouped ,31,33,34Based on the PTA thresholds ,31,33,34LAeq,8h, but they showed no significant differences. The other study that reported no significant difference showed relatively low intensity (73.0 dBA LAeq) with a short use period (1 h/day) [LAeq [LAeq, Kumar and Deepashree reported 87.97 dB LAeq at 2 h/day [LAeq at 1.99 h/day [LAeq, 2 h/day). These results exceed the regulation and are consistent with the significant poor PTA results. Furthermore, Torre and Reed reported 73.0 dBA LAeq at 1 h/day, which did not exceed the regulation, with no significant DPOAE amplitude [Regardless, the current results of the DPOAE meta-analysis did not clearly support the studies mentioned above; two of the four studies reported no significant differences at DPOAE amplitude ,24, whil1 h/day) . The stuy) [LAeq , and 95.y) [LAeq ) with a y) [LAeq ). We havy) [LAeq . In term 2 h/day , and Hus99 h/day . This ismplitude .LAeq) could not be easily integrated due to the different weights and temporal averaging according to frequency when first measured. However, it might be interesting to integrate the different measured intensity units for each study to use meta-analysis, so further investigation should be considered.The present study had limitations in terms of inconsistency in units. The intensity data of the pooled studies which we selected in this systematic review could not be synthesized because of the heterogeneity of outcome measurement , and the measurement methods varied depending on the study. More specifically, the intensity results in various studies (e.g., dB SPL, dBA, dBC, This review and analysis showed that PLD users experience a few temporary hearing changes at 4 kHz, but their hearing is restored. However, if these musical exposures are repetitive and cumulative, then these users will experience permanent hearing changes or loss, especially if exposure is at high frequencies; of further concern is that young users and/or the general public do not yet recognize the specific standards that can prevent nonoccupational noise-induced hearing loss. Therefore, it is desirable to campaign on and communicate to the public the hazards of music exposure and its negative effects on hearing in terms of public health when using PLDs, as the analysis in our study supports. In addition, health professionals have a clear opportunity to influence the public’s hearing behavior by providing appropriate education on hearing loss prevention regarding the ongoing recreational noise exposure to music via PLDs at all levels of society.


Treatment of children with CNS tumors (CNSTs) demands a complex, interdisciplinary approach that is rarely available in low- and middle-income countries. We established the Cross-Border Neuro-Oncology Program (CBNP) between Rady Children’s Hospital, San Diego (RCHSD), and Hospital General, Tijuana (HGT), Mexico, to provide access to neuro-oncology care, including neurosurgic services, for children with CNSTs diagnosed at HGT. Our purpose was to assess the feasibility of the CBNP across the United States-Mexico border and improve survival for children with CNSTs at HGT by implementing the CBNP.We prospectively assessed clinicopathologic profiles, the extent of resection, progression-free survival, and overall survival (OS) in children with CNSTs at HGT from 2010 to 2017.P < .001) and was a predictor of 5-year OS . Five-year OS improved from 0% before 2010 to 52% in 2017.Sixty patients with CNSTs participated in the CBNP during the study period. The most common diagnoses were low-grade glioma (24.5%) and medulloblastoma (22.4%). Of patients who were eligible for surgery, 49 underwent resection at RCHSD and returned to HGT for collaborative management. Gross total resection was achieved in 78% of cases at RCHSD compared with 0% at HGT (The CBNP facilitated access to complex neuro-oncology care for underserved children in Mexico through binational exchanges of resources and expertise. Survival for patients in the CBNP dramatically improved. Gross total resection at RCHSD was associated with higher OS, highlighting the critical role of experienced neurosurgeons in the treatment of CNSTs. The CBNP model offers an attractive alternative for children with CNSTs in low- and middle-income countries who require complex neuro-oncology care, particularly those in close proximity to institutions in high-income countries with extensive neuro-oncology expertise. However, after recent improvements in surgical interventions, imaging studies, and histopathologic classification systems, 5-year progression-free survival (PFS) for children with CNSTs in high-income countries (HICs) is as high as 70%-80%.7 Unfortunately, in LMICs, where 80% of the world’s children reside, 5-year overall survival (OS) for children with CNSTs is 0%-40%.9 Delivery of effective therapy for children with CNSTs demands a multimodal management of surgery, chemotherapy, and/or radiotherapy depending on the diagnosis,6 and poses a particular challenge in LMICs, such as Mexico, given the need for a comprehensive, interdisciplinary approach. This includes timely access to sophisticated neurosurgical and intensive care with experienced neuro-oncologists, pediatric neurosurgeons, neuro-radiologists, radiation oncologists, neuro-pathologists, and intensivists, which is frequently absent in LMICs.11 To deliver effective therapy for children with CNSTs in Mexico, we established the Cross-Border Neuro-Oncology Program (CBNP) in 2010 between the Hospital General, Tijuana (HGT), and Rady Children’s Hospital, San Diego (RCHSD), located 20 miles from HGT.Pediatric CNS tumors (CNSTs) remain one of the most challenging tumors to treat in low- and middle-income countries (LMICs)Key ObjectiveThe Cross-Border Neuro-Oncology Program was established across the United States-Mexico border to facilitate access to neuro-oncology care for children with CNS tumors (CNSTs) in Tijuana, Mexico, through binational exchanges of resources and expertise.Knowledge GeneratedSurvival for patients in the Cross-Border Neuro-Oncology Program dramatically improved. Gross total resection through the partnership was associated with higher overall survival.RelevanceThe cross-border model provides complex neuro-oncology care to underserved children and serves as a feasible model for other border regions. Mentored neuro-oncology care of children with CNSTs vastly improved survival at Hospital General, Tijuana. Our model offers a suitable option for children with CNSTs in low- and middle-income countries who require surgical resection, particularly those in close proximity to high-income institutions capable of offering these complex services.13 and we provided comprehensive neuro-oncology care, including access to high-quality neurosurgical services at RCHSD, and targeted training and infrastructure enhancement at HGT. In this manuscript, we describe the implementation of the CBNP and clinical outcomes of patients who participated in the CBNP.Our purpose was to assess the feasibility of the CBNP across the United States-Mexico border and improve survival for children with CNSTs at HGT. We leveraged the already established twinning program between RCHSD and HGT,14 and profound socioeconomic disparities, including a Gini index of 45.4 .15 Mexico is one of the most populous countries in the world, with high poverty rates (41.9% in 2018)17 .18 Sixty-eight million people cross this border annually, making it the world’s most transited border.19 There are vast cross-border health disparities18  diagnosed before CBNP implementation (2002-2009) died .Similar to barriers reported in other LMICs, we also found inadequate pediatric neuro-oncology training for health care providers, delays in diagnosis and radiotherapy, deficiencies in referral and diagnostic pathways, and limited access to accurate diagnosis and chemotherapy protocols.By leveraging the unique characteristics of HGT and its close proximity to RCHSD, we developed an action plan that included (1) a patient evaluation and transfer workflow at HGT and RCHSD, and (2) targeted training and infrastructure enhancement at HGT, such that patients with CNSTs that required surgical resection could be transferred from RCHSD back to HGT for additional neuro-oncology management.We used the HGT registry database to prospectively identify eligible patients. Patients age 0-21 years were eligible to participate in the CBNP if they were diagnosed with a CNST amenable for neuro-surgical intervention between January 1, 2010 and December 31, 2017, and had not yet undergone surgical resection , near-total resection, subtotal resection, and partial resection.33Data were collected from each patient’s medical record every 3 months. The following baseline variables were collected at presentation: age, sex, race/ethnicity, duration of symptoms, diagnosis date, tumor location, and neuro-imaging characteristics. After surgical resection, we collected the following variables: resection date, extent of surgical resection, histopathologic diagnosis per the 2007 WHO classification of brain tumors,Clinical outcomes included death, tumor progression, and lost to follow-up. Progression was defined as radiographic  on imaging) and/or histopathologic evidence of disease recurrence, or progression after previously documented complete remission and/or stable disease. PFS was defined as the time that elapsed between treatment initiation and tumor progression. OS was calculated from the date of diagnosis to the date of last follow up, death by any cause, or lost to follow up if no vital status was known after the event. Data were analyzed in two eras—Era 1 (2010-2013) and Era 2 (2014-2017)—to compare outcomes before and after the CBNP was fully established (December 2013).We performed descriptive statistics, used Mann-Whitney U and Fisher exact tests to determine the statistical significance of differences in continuous and categorical variables between subgroups, and performed a Cox proportional hazards regression model for continuous predictors (age at diagnosis and duration of symptoms). Variables included death, progression, and PFS and OS at 3 and 5 years, whereas age, sex, race/ethnicity, tumor type, duration of symptoms, presence of metastasis, and extent of surgical resection were covariates.34 We considered a P value < .05 to indicate statistical significance.Kaplan-Meier survival curves were generated for PFS and OS, and we calculated hazard ratios and 95% CIs. Log-rank tests were used to determine the statistical significance of differences in PFS and OS. Statistical analyses were conducted using R software (3.5.0).Children with a new diagnosis of CNST at HGT were discussed and images were shared via secure Web-platform with the RCHSD neuro-oncology team. Upon arrival at RCHSD, patients were assessed by the neuro-oncology team and admitted for surgery after obtaining relevant neuro-imaging. Postoperative care included a pediatric intensive care unit stay at RCHSD. Upon stabilization, the patient returned to HGT for additional management, which included chemotherapy, supportive care, radiotherapy, rehabilitation, surveillance, and neuro-imaging follow up. After histopathology reports were completed at RCHSD, postoperative treatment plans were discussed and designed between the teams at RCHSD and HGT. Cross-border communication between teams, including review of postoperative and follow-up images, and additional treatment recommendations, was conducted via teleconference and secure e-mail exchange. Additional information is provided in To ensure high-level care before and after surgical resection, targeted neuro-oncology training  was provided to the medical team at HGT, including pediatric oncologists (n = 4), pediatricians (n = 8), nurses (n = 32), and ancillary staff (n = 12). One initial challenge was the scarce number of pediatric oncologists who were trained to care for children with CNSTs. An advanced practice provider model was used as a solution for this shortage in which eight pediatricians received specialized training in neuro-oncology and pediatric intensive care. They now provide specialized care to critically ill patients in a dedicated pediatric intensive care oncology unit when patients with CNSTs are transferred back to HGT from RCHSD after their neurosurgical resection.37 Surgery services at RCHSD were provided as in kind. HGT leadership and the local foundation, Patronato HGT, committed to fund personnel, equipment, medications, supplies, and operational costs.A structured plan to enhance infrastructure and provide access to medications, supplies, chemotherapy, radiology, and radiotherapy services was implemented, ensuring high-quality care for patients returning to HGT for postoperative care. Chemotherapy protocols were collaboratively developed by RCHSD and HGT teams on the basis of published recommendations for LMICs and were tailored to the local resources and availability of chemotherapy agents.A total of 60 Mexican patients at HGT were diagnosed with CNSTs during the study period, and 49 underwent surgery at RCHSD. Patient characteristics are listed in The most common diagnoses were low-grade glioma , medulloblastoma , ependymoma , craniopharyngioma , and other . The most common clinical features at presentation were emesis (53%), headache (51%), balance disturbances (25%), visual impairment (22%), papilledema (8%), seizures (8%), and vertigo (7%). The majority of patients had symptoms for more than 6 months , did not have metastasis at presentation , and did not have presurgical complications, such as respiratory or metabolic aberrations . Seventeen patients (28.4%) had a ventriculostomy placement at HGT before transfer to RCHSD. Of note, none of the patients’ parents requested to continue care at RCHSD after surgery, and expressed that they were very satisfied with the follow-up care at HGT when surveyed upon their return to HGT.P < .001). None of the patients who underwent surgery at HGT (n = 11) achieved GTR  of patients who achieved GTR had surgery performed at RCHSD. Having surgery done at RCHSD, compared with HGT, was a significant determinant of GTR (eved GTR .P = .026), and symptom duration of ≥ 6 months at initial presentation was a significant predictor of decreased PFS . Age and race were not predictors of PFS or OS. Five-year OS improved from 0% before 2010 to 52% in 2017  are the third most common pediatric cancer after leukemias (49.8%) and lymphomas (9.9%), and the most common cause of death in children age 5 to 14 years.38 These statistics are consistent with those reported at HGT in our study, where 12% of pediatric oncology patients between 2010-2017 were diagnosed with CNSTs. The diagnosis make-up in our cohort is consistent with the findings of other publications in HICs and LMICs.30Whereas published data on childhood cancer epidemiology in Mexico are relatively nascent, a recent report suggests that the estimated incidence of childhood cancer is 156.9 cases per 1 million per year and seems to be continuing to increase annually.24Five-year OS for all CNSTs at HGT improved from 0%  before 2010 to 52% in 2017 after the implementation of the CBNP. There was a significant incremental improvement of 16% in 3-year OS from Era 1 (2010-2013) to Era 2 (2014-2017), highlighting the escalating positive impact of the CBNP. This increase is consistent with reports from other LMICs when long-standing twinning programs are implemented.42 Only children who underwent resection at RCHSD achieved GTR compared with patients who underwent surgery exclusively at HGT. This highlights the critical role of surgical expertise and adequate infrastructure and equipment to effectively cure CNSTs.43 Lower rates of GTR may reflect gaps in neurosurgery expertise and infrastructure in Tijuana and in similar settings in Mexico. Moreover, GTR was associated with better OS, which is consistent with the literature across many CNST subtypes,45 and supports the importance of GTR whenever possible.47 LMICs have not benefited from global advancements in neurosurgery, with most having minimal or no neurosurgical capacity.26 Moreover, there is a dramatic disparity in access to trained pediatric neurosurgeons in LMICs. There are an estimated 2,297 pediatric neurosurgeons in practice globally, with 85% operating in HICs, leaving only 350 pediatric neurosurgeons to care for a total population of 1.2 billion in LMICs with a ratio of one pediatric neurosurgeon per 3.6 million children.48GTR has an important role in improving the prognosis of patients with certain CNSTs, particularly medulloblastoma and low-grade glioma.6—patients with longer symptom duration at initial presentation had overall poorer outcomes. This suggests that timely diagnosis and swift cross-border transfer of pediatric patients with CNSTs to a site capable of providing vital, high-quality surgical resection afforded these patients the best chances of survival.As reported in prior studies, in most CNSTs—other than certain medulloblastoma subgroups and certain low-grade gliomasThis collaboration was not unilateral as RCHSD benefited significantly from this partnership. Culturally appropriate strategies to ensure treatment compliance at RCHSD were adopted from HGT, specifically in Hispanic patients. In addition, pediatric oncologists at RCHSD are now more cognizant of resource conservation, as medications and personnel are often perceived as unlimited in the United States and these resources can be scarce in LMICs.Our study must be considered in light of certain limitations. Our smaller-than-expected number of patients (based on the population size of Tijuana), related underdiagnosis of cases regionally, possible referral bias, and the evolving nature of the CBNP preclude an in-depth and consistent statistical analysis of patient outcomes over the study period. Moreover, assessing the outcome of patients who were transported to RCHSD is difficult without comparison with a control; however, denying children access to life-saving surgery for control purposes would be unethical. Instead, we may only compare outcomes with the small pool of patients who presented before the program was established. Furthermore, as a result of the lack of a well-established hospital-based registry (before the initiation of our program), specific data on imaging, diagnosis, neurosurgery, and radiotherapy delays were not systematically collected. Lastly, although the CBNP is an effective solution for a problem that was leading to the deaths of many children, we recognize that it is only a short-term step toward an established neuro-oncology infrastructure in Mexico, that it may impede the development of local neurosurgery services, and that the training of local pediatric neurosurgeons would be a long-term solution.49Many factors may hamper the structured growth of the CBNP in Baja California, including political and socioeconomic instability and a rapidly growing population. Ideally, a single regional center in an LMIC that is fully equipped and staffed could act as a referral center for pediatric neuro-oncology to improve the level of care.Future goals involve (1) growing philanthropic support for the CBNP (2) expanding access for the increasing number of patients and transitioning all facets of neuro-oncology care to HGT, (3) expanding cross-border collaboration among anesthesiologists and rehabilitation physicians, and (4) training local pathologists in neuropathology and a local neurosurgeon by instituting a neurosurgery residency program in Tijuana. Long-term sustainability requires cross-border commitment from many stakeholders and consideration of the local sociocultural perspectives. Global neuro-oncology programs should balance local challenges and opportunities and engage in capacity building through the development of training programs and formalized neuro-oncology and neurosurgery skills transfer to health care professionals in LMICs. This approach will advance their ability to effectively care for underserved children with CNSTs. Long-lasting improvements in disparate outcomes in LMICs will require cohesive health system planning with multiple stakeholders and establishing partnerships between institutions at HICs and LIMCs aimed at developing large-scale collaborative projects and research that have the potential to change national and international policy.In conclusion, through bidirectional collaboration between cross-border communities and stakeholders, the creation of programs like the CBNP is feasible and may lead to significantly improved survival in underserved children with CNSTs. There are few twinning initiatives in pediatric neuro-oncology, and the CBNP has engendered an open and bilateral exchange of resources, expertise, and cross-border access. A health systems–strengthening approach facilitated interdisciplinary collaboration, enhanced infrastructure, and allowed for local capacity building. The CBNP offers opportunities for replication in HIC institutions in close proximity to LMICs across the United States-Mexico border and throughout the world.


Coccinella undecimpunctata and Hippodamia variegata are effective predators of various insect pests and widely distributed in different regions of Saudi Arabia. The present study aimed to estimate the pathogenicity of an indigenous Beauveria bassiana isolate on all developmental stages of the abovementioned predators. The obtained results generally showed there were no significant effects on both predator’s mortality and most biological parameters as indirect assay also were not affected as survival, duration, adult longevity, and fecundity.Integrated pest management should use integrated or compatible control agents. Most of chemical pesticides have a negative effect on the natural enemies and beneficial microorganisms. Compatible bioagents as entomopathogenic fungi with the natural enemies could achieve higher control impact. Therefore, it is important to test the safety of entomopathogenic microorganisms on the entomophagous insects. The predatory coccinellids are the most effective predatory insect species where attack various insect pests and play very important role in biological pest control in different ecosystems. From these, Beauveria bassiana on all developmental stages of two indigenous coccinellids; Coccinella undecimpunctata and Hippodamia variegata through three application methods; direct spray, contact method, and feeding on aphids treated with the fungus (ingestion). Also, indirect effect on all developmental stages resulted from 1st larval instar treated with these application methods. All treatments were done with a concentration of 1 × 105 which was recommended in previous studies for different aphid species with a control of 0.02% Tween 80 (v/v). The mortality of 1st larval instar of both H. variegata and C. undecimpunctata and pupal stage of C. undecimpunctata were significantly increased with spray method only. Also, contact method achieved significantly higher mortality on 1st larval instar of C. undecimpunctata only. Regard to indirect effect, except of mortality of 1st larval instar of both predators and 2nd larval instar of H. variegata, other developmental instars/stages of both predators were not affected by B. bassiana through the three tested application methods in the mortality, duration, survival, cumulative survival male and female longevity, and fecundity. Therefore, both tested predatory coccinellids could be compatible with this indigenous isolate of B. bassiana where, in general, there are no negative effects of the fungus on both predators.This study aimed to estimate the virulence of an indigenous  The chemical pesticides are still a priority in pest control, allowing growers to produce crops of sufficient quality at low costs . In contCoccinella undecimpunctata L., and Hippodamia variegata Goeze (Coleoptera: Coccinellidae) are effective predators of various insect pests such as aphids either in greenhouses or fields due to their high feeding capacity [C. undecimpunctata and H. variegata are widely distributed in different regions of Saudi Arabia [The predatory insects belonging to family Coccinellidae (Order: Coleoptera) include important natural enemies of several phytophagous pests. They attack various insect pests as aphids, whiteflies, thrips, jassids, mealybugs, lepidopterous eggs, and larvae as well as other small insect pests. They play an important role in biological control of insect pests attacking various plant species ,4. The pcapacity ,6. Both i Arabia ,8,9.Beauveria bassiana  Vuillemin  are generalist EPF infecting phytophagous insects and predatory coccinellids [B. bassiana has many positive attributes such as potential infection of up to 80% of pest populations, high genetic variation among various isolates, great diversity, potential mortality of all stages of the targeted pest, high capacity for vertical and horizontal dispersal, and without significant environmental implications [Entomopathogenic fungi (EPF) often contribute the natural enemies such as predatory coccinellids to reduce the population of herbivorous insects in different ecosystems . On the inellids . B. bassications ,13. C. undecimpunctata indicated that B. bassiana failed to differentiate between these predators and pests that present in the same environment [B. bassiana with high inoculum densities cause mortality to adults of Coccinella septempunctata, while mortality could be achieved after field application with extended contact with spores during the mobility on leaves surface [B. bassiana had different pathogenicity rates on the same species such as C. maculata [Beauveria spp. did not regulate the populations [B. bassiana to control of targeted pest depends on high effect against pests and also low pathogenicity against non-target insects, especially natural enemies.The field monitoring of some insect predators included ironment . Studiesironment . Use of ironment ,16. The ironment ,17. B. b surface . Also, dmaculata . The preulations . The intulations ,21. ThusB. bassiana on plants targeted insect pests as aphids would likely expose these pests and other beneficial insects such as predators to this fungus through different ways as direct spray, contact or predation the infected prey. Due to the high importance of predatory coccinellids in biological aphid control, it is important to determine the influence of other biological agents on them, such as insect pathogens and parasitoids. In this study, we examined the effect of indigenous B. bassiana on all instars/stages of C. undecimpunctata and H. variegata through three different application methods; direct spray, contact and feeding on treated prey (ingestion). Moreover, the treated coccinellids at 1st larval instars were investigated till the adult death to determine the side effect on all biological parameters of all the remaining instars/stages. These results could give indications about the compatibility of the using of these bioagents for aphid control in the field.Spray applications of EPF as B. bassiana from Saudi Arabia, which was isolated from Taif region  and identified by morphological and molecular tools (Accession numbers: LC338054) [3 conidia/mL on PDA media in a Petri dish and incubated for 24 h at 25 °C. Then, germinated conidia were estimated by a phase contrast microscope  with 400× of magnification [5 was considered as a final concentration of 1 × 105 conidia/mL.The fungus isolate used in this study was an indigenous isolate of C338054) . Conidiafication . AccordiH. variegata and C. undecimpunctata were obtained from a rose field in Taif region, Saudi Arabia. Each couple was reared in a cylindrical plastic vessel (10 cm diameter and 8 cm high) with a hole in the lid (4 cm in diameter) and covered by gauze for proper ventilation. They were maintained with Ephestia kuehniella Zeller  eggs from Predators Mass Production Laboratory, Faculty of Agriculture, Cairo University, Egypt, and water on a cube of sponge, and their eggs collected daily. Eggs were transferred to plastic Petri dishes, and also larvae were reared in the same dishes till pupation. The rearing was continued for 3 generations where instars/stages of 4th generation were used in the experiments. Individuals of males and females of coccinellid predators i.e., Macrosiphum rosae L. (Hemiptera: Aphididae) were used for ingestion experiment as prey. Infested leaves of rose plants with this aphid were collected and transferred to the laboratory on the same day of the experiment [Adult individuals of rose aphid, periment .B. bassiana for eggs, larvae, pupae and adults of both coccinellid predators was estimated by three different application methods; i.e., spray, contact and ingestion of prey. A concentration of 1 × 105 conidia/mL (with 0.02% of Tween 80) was used for all bioassay methods. This concentration was recommended for control of M. rosae [v/v). Spraying of fungus suspension or Tween 80 (0.02%) was done by Bürkle spray bottle w/hand pump, 250 mL purchased from Thomas Scientific .The virulence of M. rosae  and grapM. rosae . The con5 conidia/mL. Each instar/stage treatment or control consisted of 3 replicates except eggs where 100 eggs were treated as only one replicate. After treatment, all instar/stages (except eggs) were kept individually in a Petri dish with sufficient number of E. kuehniella eggs. The mortality was recorded daily till 5th day after treatment. In order to confirm fungal infection, dead individuals were kept in an environmental chamber  with controlled conditions of 26 ± 1 °C, 14 Light: 10 dark (L:D) and 80 ± 5% relative humidity (RH), and observed till whether appearance of mycosis signs or for 10 days after treatment.Eggs, all four larval instars, pupa, and adult males and females of both coccinellid species were treated with spray application. Each 20 individuals  as one replicate except eggs were placed in a Petri dish and sprayed with 1.2 mL suspension of 1 × 10E. kuehniella eggs and investigated for five days for mortality. Three replicates, each one consisting of 20 individuals, were used for each treatment and control. Dead individuals were kept as previously mentioned.All four larval instars and adult males and females of both coccinellid species were treated with contact method. A filter paper was placed in each Petri dish and 1.2 mL of fungus suspension was sprayed on the filter paper. The Petri dishes with filter papers were left to dry for 1 h. Then, each individual was placed in a Petri dish with sufficient number of M. rosae those were treated by spray method on the same day. Twenty aphid nymphs on 2–3 leaves of rose plant were placed in a Petri dish and then sprayed with the fungus suspension. After 1 h, the aphid nymphs were transferred to another Petri dish with an individual of predator for 24 h. After this period, the predator was transferred to new petri dish with sufficient number of E. kuehniella eggs for five days and investigated for mortality. In the control, aphids were treated with 1.2 mL of 0.02% of Tween 80 (v/v). Three replicates  were used for each treatment and control. Dead individuals were kept as previously mentioned.For the contact method, all four larval instars and adult males and females of both coccinellid species were maintained with aphid nymphs of B. bassiana on both predators, the previous techniques of spray, contact, and ingestion methods was carried out with 30 individuals of newly 1st larval instar of both predators. Also, 30 individuals of non-treated newly 1st larval instar of both predators were used as control. After these treatments, all treated and non-treated individuals were kept individually in a Petri dish with E. kuehniella eggs as prey. All individuals were investigated daily till adult emergence to estimate durations and mortality. After adult emergence, each couple was provided with E. kuehniella eggs as prey and kept in a cylindrical plastic vessel with a hole in the lid (4 cm in diameter) and covered by gauze for proper ventilation. Adults were investigated daily till death for estimation of longevity and fecundity.To study the side effect of All experiments were done under laboratory conditions of 26 ± 2 °C, 65 ± 8% RH and 14:10 h (L:D). This low humidity was used because it is relatively compatible with the environmental conditions at Taif, Saudi Arabia where the humidity in Taif is ranged from 30% to 68% at day and from 41% to 78% at night, according to The General Authority of Meteorology and Environmental Protection of Saudi Arabia.X2-test) was used to compare both hatchability and cumulative survival rates for those that had one value for each treatment or control. Meanwhile, t-test was used for each predator species to compare between two groups only; i.e., controls and spray treatments on pupa.Prior to data analysis, the homogeneity of the variances was subsequently tested by Levene’s test by Statistical Package for Social Sciences (SPSS) program . One-way analysis of variance (ANOVA) was conducted for experiments contained three treatment groups beside the control; i.e., larval mortality, larval duration, pupal duration, and all adult parameters. Means were compared by the Duncan test (α = 5%). Chi-square test . On the other hand, the mortality of 1st larval instar was significantly different  where the mortality from the spray method (15%) only was significantly different from that of the control (3.33%) and both of them were not significantly different from those of contact (10%) and ingestion (8.33%) methods  on hatching rate between treated (90%) and non-treated (86%) eggs.In all developmental stages/instars, except of the 1st larval instar, the mortality rates were not significantly affected by application methods of  methods . Regard B. bassiana  where the larval mortality from both spray (18.33%) and contact (10%) methods was significantly different from that of the control (3.33%) . In contrast, the mortality rates of other developmental stages/instars were not significantly affected by application methods of B. bassiana . Hatchability of egg stage treated with the spray method (85%) did not differ significantly from the control (87%) .The mortality rates of 1st larval instar were significantly affected by application methods of  (3.33%) . Meanwhi (3.33%) . Also, fH. variegata were significantly increased with both spray and ingestion methods  compared to those with both contact method and the control   . MeanwhiThe survival for each individual instar/stage and accumulated survival  were not significantly different among all treatments and the control  being acB. bassiana on adult stage treated at their 1st larval instar with three different application methods of the fungus  and ingestion (3.19 days) methods than those by both contact method (2.71 days) and the control (2.79 days) . In the same context of H. variegata, the durations of other developmental larval instars and pupa, their survival, male and female longevity, and fecundity (Exactly as in 79 days) . In contecundity  were notecundity .H. variegata and C. undecimpunctata and pupal stage of C. undecimpunctata were significantly increased with spray method only. Also, contact method achieved significantly higher mortality on 1st larval instar of C. undecimpunctata only. Other developmental stages of H. variegata and C. undecimpunctata were not affected by the tested isolate of B. bassiana through the three tested application methods. In this context, B. bassiana achieved the highest mortality rate on larval stage of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) than other developmental stages [B. bassiana is compatible with beneficial insects. For examples, B. bassinna was not pathogenic to different natural enemies such as C. septempunctata [Chrysoperla exotera (Navás) (Neuroptera: Chrysopidae) were not affected when treated with high concentration of B. bassiana [Information that shows the susceptibility of indigenous species of coccinellids to indigenous EPF is very important for using them in a combination in pest control programs . Selectil stages . Similarpunctata . The prebassiana .Coleomegilla maculata fed on Colorado potato beetle Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) infected with B. bassiana and contaminated pollen with B. bassiana resulting in no mortality of C. maculata [H. variegata was less susceptible than C. undecimpunctata in their 1st larval instar and pupa. In other way, H. variegata in alternative option indicated a significant attraction towards aphids non-infected than aphids infected by B. bassiana from 1 to 3 days after treatments with a concentration of 1 × 105 conidia/mL. This suggested that H. variegata could avoid B. bassiana under laboratory conditions. Therefore, this fungus was a negligible threat to this predator [B. bassiana, Metarhizium rileyi and Metarhizium anisopliae on Chrysoperla externa (Hagen) indicated that there were no differences among the application method or concentration of conidia. Also, no larval mortality of C. externa above 3% at 4 days after treatments. Meanwhile, after 5 days, B. bassiana only achieved significant mortality in all larval instars  [Our results indicated that both tested coccinellids were not affected in their mortality with feeding on aphid treated with the fungus weather for the same coccinellid instar/stage or for instar/stage resulted from treated 1st larval instar. In this context, maculata . This inpredator . Our res% in L3) .B. bassiana, which was isolated from tarnished plant bug, Lygus lineolaris, can infect various insect predators including H. axyridis, but with LC50 values of 3- to 90-fold those of L. lineolaris [Chrysoperla rufilabris [H. axiridis, Orius insidiosus, H. convergens and C. maculata [Harmonia axyridis and Olla v-nigrum (Coleoptera: Coccinellidae) were collected from the same habitats indicated that O. v-nigrum had low mortality and none of H. axyridis were infected with B. bassiana [O. v-nigrum and the introduced H. axyridis. Moreover, B. bassiana that isolated from naturally infected O. v-nigrum was not pathogenic with a concentration of 2.5 × 105 conidia/mL to the introduced H. axyridis and the indigenous Coleomegilla maculata but pathogenic to the indigenous species O. v-nigrum, Hippodamia convergens and Cycloneda munda.Generally, the same fungus isolate could have diverse effects on different hosts, even if they are from the same family. The American authorized strain NI8 neolaris . In contfilabris  and low maculata . Moreovebassiana . This inH. variegata. Similarly, the 4th larval instar of C. undecimpunctata when fed on aphid treated with B. bassiana (Biosect) did not affected in its duration but duration of its pupae was significantly decreased than that of the control [Regard to the side effect on treated 1st larval instar and their other larval instars, pupa, and adults. Both spray and ingestion treatments had a significant increase in 1st larval duration of both coccinellids but only ingestion treatment had a significant increase in 2nd larval duration of  control .B. bassiana was not affected in the male and female longevity but fecundity was significantly lower than that of the control [C. septempunctata were influenced similarly by B. bassiana [All treatments in this study did not significantly affect the male and female longevity and fecundity of both coccinellid species. In other study, adults fed on aphid treated with a low concentration (0.5 g/L) of  control . Also, bbassiana .B. bassiana through the three tested application methods in the mortality, duration, survival, cumulative survival, adult longevity, and fecundity. Therefore, both tested predatory coccinellids could be used in association with this isolate of B. bassiana for sustainable pest management.Both tested coccinellid predators, in general, were not affected by


Hearing impairment is a common chronic condition which can be closely related to people’s health. However, current studies on this topic are quite limited in developing countries, and few with standardized audiometric measurement and multiple health outcomes. Therefore, we aimed to explore the association between hearing impairment and its severity with physical and mental health among Chinese middle-aged and older adults.We obtained data from two sources: (1) China Health and Retirement Longitudinal Study (CHARLS) 2011, 2013, and 2015, in which hearing impairment was measured by asking whether participants aged 45 years old had hearing problems; and (2) Hearing Survey 2019, the baseline survey of a randomized controlled trial conducted in Shandong Province of China, including 376 middle-aged and older participants. The severity of hearing impairment was identified by pure tone average of hearing thresholds at 0.5, 1, 2, and 4 kHz.In CHARLS, 1248 (8.36%) participants suffered from hearing impairment at baseline, and hearing-impaired individuals were more likely to have chronic diseases, impaired activities of daily living (ADLs), impaired instrumental activities of daily living (IADLs) and depressive symptoms. For the 376 hearing-impaired participants in Hearing Survey 2019, 30.32, 38.30 and 31.38% of them had moderate, severe and profound hearing impairment, respectively. As the severity of hearing impairment increased, individuals were likely to have impaired ADLs, impaired IADLs and depressive symptoms.Hearing impairment and its severity were closely related to multiple physical and mental health outcomes among Chinese middle-aged and older adults. Actions should be taken to prevent and treat hearing impairment, so as to improve people’s health and well-being. Hearing impairment is one of the most common sensory dysfunctions, which adds to the burden of physical and mental health extensively . AccordiIn addition, the risk of hearing impairment rises rapidly with age, so it is becoming an increasingly serious public health concern . More thHowever, current studies on this topic are very limited and most of them are conducted in developed countries. It has been shown that hearing impairment brings about poor quality of life in community-dwelling older adults , presentBased on the nationally representative data from China Health and Retirement Longitudinal Study (CHARLS) 2011, 2013, 2015 and the latest Hearing Survey 2019, our study incorporates both self-reported hearing data and standardized audiometric measurement, aiming to gain a comprehensive understanding of the association between hearing impairment and its severity with multiple health outcomes in Chinese middle-aged and older adults. This study will draw wide public attention to the association of hearing impairment and multiple health outcomes, as well as turning to early prevention and treatment.Currently there is no single database available that could provide information on the variables of hearing impairment and its severity in China. Therefore, we combined two data sets: (1) the CHARLS 2011, 2013, 2015 pooled data; (2) the Hearing Survey 2019 data. The data of CHARLS 2011, 2013, 2015 are based on the national level without the severity of hearing impairment, and the Hearing Survey 2019 is only from a city but with the severity of hearing impairment, which is evaluated by objective audiometric measurement.The first dataset CHARLS is a long-term tracking project, with its baseline survey conducted in 2011 and follow-up surveys in 2013 and 2015, eying on the community-dwelling Chinese adults aged 45 years old or above . CHARLS The second data set Hearing Survey 2019 is the baseline survey of a randomized controlled trial in Linyi City, Shandong Province of China to investigate the association between the severity of hearing impairment and health outcomes. We included middle-aged and older adults with moderate hearing impairment and above  > 40 dB), and with no hearing aids use at baseline. Those in the treatment group were prescribed with hearing aids, while those in the control group received no intervention. The primary outcome is changes in their health conditions over a 12-month period. According to the list provided by the hearing center of Linyi Disabled Persons’ Federation, 500 people were randomly selected, of which 36 patients were approached and were unwilling to give informed consent. In addition, 12 patients were excluded from the study because they were unable to understand the questionnaire, and 22 patients did not meet the inclusion criteria for the Hearing Survey 2019. We finally got the sample size of 430, of which 376 people were 45 years old and above.In CHARLS 2011, 2013 and 2015, hearing status was derived by asking whether respondents have hearing problems or not. The result is a subjective answer “yes” or “no”. Prior studies have proved that a single-item question about an individual’s hearing ability is moderately useful and valid to assess hearing and can be used for a population-based study , 28.Hearing Survey 2019 measures hearing status by pure-tone average (PTA) at the thresholds of 0.5, 1, 2, and 4 k Hz. According to the classification by World Health Organization, those are defined as moderate hearing impairment if PTA > 40 dB and PTA ≤ 60 dB, severe hearing impairment if PTA > 60 dB and PTA ≤ 80 dB, and profound hearing impairment if PTA > 80 dB .Chronic diseases: Individuals were asked whether they had been diagnosed with chronic diseases, including hypertension, dyslipidemia, diabetes, cancer, chronic lung disease, liver disease, heart attack, stroke, kidney disease, digestive disease, arthritis or asthma. If individuals reported having at least one of these chronic diseases, we defined them as having chronic diseases.ADLs: Individuals were asked whether they had any difficulty with activities of daily living, including dressing, bathing or showering, eating, getting into or out of bed, using the toilet, or controlling urination and defecation. Impaired ADLs was defined as difficulty or inability with any of the activity .IADLs: Individuals were asked whether they had any difficulty with instrumental activities of daily living, including doing household chores, preparing hot meals, shopping for groceries, making phone calls, taking medications, or managing money. Impaired IADLs was defined as difficulty or inability with any of the activity .Depressive symptoms: Both surveys applied the screening tool Center for Epidemiologic Studies Depression Scale-10 items (CES-D-10) Chinese version to detect depressive symptoms . The CESIn both CHARLS and Hearing Survey, we incorporated several variables to measure health status. Physical health was measured by whether they had chronic diseases , impairePrior research has identified several confounders that are associated with hearing impairment and health, and should be included in the analysis as covariates , 7, 18. P-value less than 0.05 considered statistically significant.Descriptive analyses were used to present sample characteristics and hearing status. We used analysis of Variance (ANOVA) and the Chi-square test to compare characteristics between different hearing impairment categories. Logistic regression models and marginal effects were employed to predict the probabilities of having chronic diseases, impaired ADLs, impaired IADLs, and depressive symptoms with changes in hearing status while potential confounders were controlled . Before The characteristics of CHARLS Baseline 2011 are shown in Table The characteristics of Hearing Survey 2019 for 376 participants aged 45 years old and above are shown in Table Table Results from CHARLS pooled data indicated that, hearing impairment was significantly related to the greater risk in physical and mental health. Compared with those having no hearing impairment, the prevalence of having chronic diseases , impaired ADLs , impaired IADLs  and depressive symptoms  increased if individuals had self-reported hearing impairment.Results from Hearing Survey 2019 showed that, different levels of hearing impairment severity were linked to different risks of having impaired ADLs, IADLs, and depressive symptoms.To be exact, for those with severe and profound hearing impairment, the prevalence of impaired ADLs was significantly higher than the reference group (people with moderate hearing impairment) . For those with profound hearing impairment, the prevalence of impaired IADLs  and depressive symptoms  was significantly higher than the group of moderate hearing impairment.Among people with moderate to profound hearing impairment, the prevalence of chronic diseases did not show large differences compared with moderately hearing-impaired people . And groups with moderate and severe hearing impairments show no significant differences in the prevalence of having impaired IADLs  and depressive symptoms .With the population aging, an increasing number of people are living with hearing impairment, especially during their later-life years, which can be associated with multiple health problems. Based on two data sets from nationally representative CHARLS pooled data and the latest Hearing Survey 2019 data, this study is the first to present the association of hearing and its severity with multiple health outcomes in China. Overall, hearing-impaired individuals in CHARLS were more likely to have chronic diseases, impaired ADLs, impaired IADLs and depressive symptoms. For the hearing-impaired participants in Hearing Survey 2019, as the severity of hearing impairment increases, individuals were also more likely to have impaired ADLs, impaired IADLs and depressive symptoms.What we have found among hearing-impaired adults in China is generally consistent with previous studies about the effects of hearing impairment on people’s physical and mental health. People with more severe hearing impairment tend to be older , male 4, and lesOur results further demonstrated the association of different severity of hearing impairment with physical and mental health outcomes. The prevalence of impaired ADLs showed an elevated increase for those with severe to profound hearing impairment, compared with moderate hearing impairment. For those with profound hearing impairment, the prevalence of impaired IADLs and depressive symptoms were much higher than those with moderate hearing impairment. The underlying mechanism may be that, since ADLs measures basic functions in daily activities and IADLs measures functions in more subtle activities, hearing impairment may be more related to the decline in certain brain structures that control these functions . And heaSince hearing impairment can be difficult to detect and cure, and is closely related to health, it is imperative to raise awareness and take effective measures. For newborns, the screening and prevention of hearing impairment should be taken as early as possible. For those with hearing impairment, especially with moderate and above hearing impairment, it is necessary to provide rehabilitative devices to compensate for the loss of functions, such as wearing hearing aids , as peopLimitations of our study are that, first, the heterogeneity between two different data sets should be noted, and extrapolation from the Hearing Survey 2019 should be cautious because the sample is from only one city, which may not be representative of the hearing-impaired adults in China. Second, some of the hearing and health variables are determined by participants’ self-reported data, which may bring some bias. Third, although some confounders have been controlled, other undetectable confounders may also affect the results .Despite of above limitations, the main strength lies in that, our study focuses on the association between hearing impairment and health outcomes in China, which is a relatively unexplored and prospective topic in developing countries. To be exact, we not only used 3 waves of national representative CHARLS data, but took a step further to investigate different severity of hearing impairment by the latest Hearing Survey 2019 to elucidate the complex interplay between hearing impairment and health. We applied multiple physical and mental health outcomes to demonstrate the association from different perspectives and we combined both self-reported hearing status and objective audiometric measurement, all of which can act as more profound and compelling evidence to the extant literature.The high prevalence and increasing severity of hearing impairment have been a tendency in the aging society. Hearing impairment and its severity were found to be closely correlated with physical and mental health in Chinese middle-aged and older adults. Immediate actions should be taken to prevent and treat hearing impairment, so as to improve their health and well-being of hearing-impaired people.