Frequency Of Hearing Impairment Research Articles

Frequency of Hearing Impairment in School-Going Children of District Hyderabad, Sindh, Pakistan

Frequency of Hearing Impairment in School-Going Children of District Hyderabad, Sindh, Pakistan

Frequency of Hearing Impairment among Medical College Students in Peshawar, Pakistan: Insights from a Smartphone Used Survey

Background: Hearing loss is a major public health concern affecting millions globally. According to the World Health Organization (WHO), more than 1 billion young adults are at risk of developing hearing loss due to unsafe listening practices. This study utilizes smartphone-based technology to assess the hearing health of medical students in Peshawar.Objectives: The primary goal of this study was to determine the prevalence of hearing impairment among medical students and to pinpoint any probable causes of hearing loss in this student population.Materials and Methods: A cross-sectional study involving 109 undergraduate medical students, assessed their hearing health using the HearWHO application, which assigns scores ranging from 0 to 100, categorized as i) above 75, ii) 50-75, iii) below 50.Results: A total of 109 students (54 males, 55 females; mean age: 21.89) were surveyed. On testing the hearing health of the participants with the HearWHO application, 12.8% (n=14) were in the category of scores above 75, 73.4% (n=80) were in the category of the score 50-75, and 13.8% (n=15) were in the category of the score below 50. 32.1% (n=35) were observed to be utilizing their personal audio devices (PADs) at a high volume.Conclusion: The survey highlighted varied PADs usage among participants, notably with many using PADs for long durations and at high volumes. These findings emphasize the need for monitoring and promoting safe PADs usage among young adults, potentially influencing hearing health promotion and prevention strategies.Keywords: Hearing impairment, Medical Students, Smartphone

Adverse Effects of Extended high frequency Hearing Impairment on Digit in Noise Perception

Purpose: The present study aims at comparing the adverse effects of EHF hearing loss with Digit In Noise perception, between two age groups-Young adults and Early adulthood.Methods: A total of 30 participants aged between 18 to 25 years as Young adults group and 26 to 35 years as early adulthood group were included in the study. All the participants were having EHF hearing loss with normal conventional audiogram. Digit in Noise test was carried out for these subjects. Digit in Noise recognition threshold was considered here.Results: When compared to young adults group, the early adulthood population exhibited poorer thresholds at EHFs as well as 95% of the participants in this group showed poor scores in DIN test. Among the young adults group, 46.6% showed poor DIN scores.Conclusions: Poor DIN recognition thresholds along with EHF loss despite normal conventional audiogram results necessitate the inclusion of EHF audiometry and Speech in noise test as part of the routine audiological evaluations. This helps in early detection, monitoring and prevention of hearing loss even during the third decade of human life.

Location of the AICA influences the severity but not occurrence of ISSNHL: A reappraisal using high-resolution 3 T MRI

ObjectiveTo investigate the potential influence of anatomical variation in the anterior inferior cerebellar artery (AICA) on the occurrence and severity of idiopathic sudden sensorineural hearing loss (ISSNHL). MethodsNinety ISSNHL patients were enrolled. The anatomical location of the AICA was exhibited using high-resolution magnetic resonance imaging (MRI), and the various AICA types classified by previously reported Chavda and Gorrie methods were analyzed. The severity of hearing loss in the ipsilateral ear among different AICA types was compared. ResultsApproximately 85.6% of subjects had unilateral ISSNHL (uISSNHL), and the others had bilateral ISSNHL (bISSNHL). In the uISSNHL group, the ratios of different AICA types were similar between the ipsilateral and contralateral ears. The ratios of the different AICA types in the bISSNHL group were similar to those in the uISSNHL group. In the uISSNHL group, pure tone audiometry (PTA) thresholds at 2 kHz, 4 kHz and 8 kHz of patients with Chavda type II AICA were higher than those of patients with Chavda type I and type III, with a significant difference at 4 kHz between type I and type II. There was a tendency of the PTA threshold in patients with Chavda type II or Gorrie type C to gradually increase from low to high frequency zones. ConclusionWhen the AICA enters the IAC (Chavda type II) or crosses between the 7th and 8th cranial nerves (Gorrie type C), the severity and frequency of hearing impairment in ISSNHL but not the occurrence of ISSNHL will be affected.

Workforce Diversity and Occupational Hearing Health

Hearing loss is one of the more common occupation health hazards across the globe yet is preventable. Extensive research has been done across a number of industries measuring the magnitude and frequency of hearing impairment. This study uses the National Health and Nutrition Examination Survey data to analyze hearing impairment in the United States. Regression and structural equation models were developed utilizing this publicly available data. A statistically significant correlation exists between general hearing condition and ethnicity, χ2 (30, N = 8897) = 264.817, p < 0.001. A statistically significant correlation exists in this database between general hearing condition and gender, χ2 (6, N = 8897) = 40.729, p < 0.001. An ordinal logistic regression was significant between the general health and ethnicity, χ2 (30, N = 5968) = 212.123, p < 0.001. A structural equation model presents the first of its type for this area of research. Focusing on addressing diversity issues may be the foundation for hearing health improvement. Tools such as smartphone apps may be useful for tracking hearing loss within the workforce.

Состояние слуховой функции у детей-воспитанников детских домов, эвакуированных из зоны военных действий

In this study, the structure and frequency of hearing impairment in children who lived at various times in the territories of military operations were studied. The high prevalence of otorhinolaryngological diseases, combined with low detectability, entails formidable complications, leads to a decrease in the quality of life of the child and the family as a whole, and negatively affects the general level of public health. In total, during the study, 398 children aged 5 to 16 years old were examined, who were in the temporary accommodation center of the Romashka children’s resting camp. The children are students of orphanages in the Donetsk People’s Republic (DPR) and the Luhansk People’s Republic (LPR) evacuated from the war zone in the first days of the Special Operation. There were 216 girls (54.3%) and 182 boys (45.7%) among them. The average age of children was 8.5 years. Hearing loss was detected in 33 children (8.3%). Two children (0.5%) had a severe form of sensorineural hearing loss of 3–4 degrees. Two children (0.5%) had a mild form of sensorineural hearing loss of 1–2 degrees. Four children (1%) had unilateral chronic sensorineural hearing loss. The diagnosis of otitis media with effusion was established in 20 children (5%), tubo-otitis, in three patients (0.8%). Suspicion of an anomaly in the development of the middle ear, in 2 children (0.5%). Examination of children in orphanages evacuated from the DPR and LPR did not reveal a high prevalence of hearing impairment. Sensoneural hearing loss: 2%, conductive hearing loss: 6.3%. The results of the work demonstrate a wide potential for improving hearing health in the examined children. Active diagnostics of hearing pathology is shown to all children in orphanages. After treatment of conductive hearing pathology, mandatory audiological monitoring is indicated, despite the subjective improvement in hearing.

Functional consequences of extended high frequency hearing impairment: Evidence from the speech, spatial, and qualities of hearing scale.

Hearing loss in the extended high frequencies, despite a normal audiogram, could affect speech-in-noise recognition. However, it is not known if extended high frequency (EHF) hearing loss is associated with everyday listening and communication deficits. The present study aimed to determine the functional effects of impaired EHF hearing among adults using the Speech, Spatial, and Qualities of Hearing Scale (SSQ). A secondary objective was to evaluate the relationship between objective (speech-in-noise recognition) and subjective (SSQ) measures of hearing function. Listeners with EHF hearing loss provided lower SSQ ratings compared with their EHF-normal counterparts. The lower ratings could not be attributed to the age or standard audiogram of the listeners. Ratings from more than 50% of EHF-impaired listeners were below the 2 SD cutoff point obtained from EHF-normal listeners. The mean speech recognition threshold was poorer for EHF-impaired listeners, and a poorer speech recognition threshold was associated with lower SSQ ratings, i.e., poorer self-reported hearing ability. For some listeners, EHF hearing loss could be the missing link between self-reported hearing difficulty in the presence of a normal audiogram. These findings provide evidence for the functional deficits associated with EHF hearing loss and invoke the need for future investigations into the management of EHF loss.

Frequency of Hearing Impairment in Siblings of Hearing Impaired Children

Background: It has been reported that hearing impairment is significantly associated with multiple negative outcomes including depression, loneliness, altered self-esteem, and diminished functional status. The deaf and hard of hearing community is very diverse as for as cause, age of onset and degree of hearing loss. Aim: To determine the frequency of hearing impairment in siblings of hearing impaired children. Methods: This is descriptive observational study was conducted between September 2015 to February 201 at FMH College of Medicine and Dentistry. A total of 100 hearing impaired children aged between 4 to 20 years were included in this study. A self-designed questionnaire was used to assess the parental point of views. The questionnaire was designed as a data collection tool in order to collect the frequency from the HIC regarding their siblings hearing impairment. Results: Results indicated that out of 100 subject 63(63%) were male and 37(37%) were female and the mean age of patients was 12.28±4.13 years. On asking the HIC about total number of siblings 15(15%) responded that they had only 1 sibling, 28(28 %) responded that they had only 2 siblings, 17(17%) responded that they had only 3 siblings, 17(17%) responded that they had only 4 siblings, 14(14%) responded that they had only 5 siblings, 1(1%) responded that they had only 6 siblings and 8(8%) responded that they had only 7 siblings. Conclusion: It was concluded from the above study that frequency of hearing impairment in siblings of hearing impaired children is in high proportion and this high proportion of hearing impairment is because of cousin marriages, pressure due to family structure, genetic change. Keywords: Hearing impairment, hearing loss, frequency, Siblings.

Literature analysis of hot topics on occupational noise-induced hearing loss

Objective: To analyze the literature of related research reports on occupational hearing loss (ONIHL) , study the characteristics of the subject and determine the research hotspots. Methods: In December 2020, PubMed database was searched by bibliometrics for ONIHL published in PubMed database from January 1971 to December 2020. Bicomb 2.03 software was used to extract the subject. The publication year, publication country, source magazine and subject words were summarized and analyzed. Results: A total of 1 473 papers were included in this study, and the number of papers was 66 from 1971 to 1980, and 628 from 2011 to 2020, an increase of nearly 10 times. The top three countries were the United States, China and Germany, with 31.5% (464/1473) , 11.5% (171/1473) and 6.2% (91/1473) ; The cross-sectional study was the most applied type; The top five words for 2011-2020: Mental Illness, polymorphism, cardiovascular disease, high frequency hearing impairment and standards and regulations. Conclusion: Susceptibility Genes, Psychological Disorders, Cardiovascular Diseases and Risk Assessment are hot areas in ONIHL at present. Researchers should focus on major fields and grasp future trends as a whole.

Asymptomatic hearing loss-a missed symptom of COVID-19

<p class="BodyA"><strong>Background: </strong>COVID-19 pandemic is caused by SARS CoV2. The last reference of pandemic was Spanish flu in 1918 which caused hearing loss in many patients. The effect of COVID-19 is an interesting issue in audiology. Not much studies have been done; therefore, this kindled our interest to have a study on audiological profile of asymptomatic COVID-19 patients.<strong></strong></p><p class="BodyA"><strong>Methods:</strong> The 20 cases in the age group of 20 and 50 years who were confirmed positive for COVID-19 formed the study group. 20 subjects who had normal hearing (Audiometric threshold at or better than 15 db HL) were used as control group. Pure-tone audiometry (PTA) was done for both the group on day 7 and 30. Air conduction and Bone conduction were measured. The audiometric thresholds were measured using the modified Hughson-Westlake method.</p><p class="BodyA"><strong>Results:</strong> High frequency hearing impairment was found in 9 out of 20 patients in the study group on day 7. Out of the 9 affected patients 7 patients showed improvement upon further testing done on day 30.</p><p class="BodyA"><strong>Conclusions: </strong>Like anosmia and ageusia, hearing loss can be considered as one of the clinical features in COVID-19 patients. This study was recorded to find a significant hearing loss in asymptomatic COVID-19 patients and thus sheds light on the auditory problem that people are experiencing during these difficult times and for future reference on pandemic research.</p>

High frequency hearing impairment and cardiovascular disease in Canada: Results from the Canadian Health Measures Survey.

Noise-induced stress may precipitate cardiovascular diseases. This research assessed the association between sensorineural bilateral high frequency hearing loss (HFHL), as an indication of excessive noise exposure, and cardiovascular outcomes. Participants (n = 6318, ∼50% male) 20-79 years were recruited through the cross-sectional Canadian Health Measures Survey. Questionnaires included several demographic and health-related variables. Audiometry and blood/urine collection took place in a mobile examination centre. Average thresholds ≥25 dB averaged across 3, 4, and 6 kHz defined HFHL. Logistic or linear regression models explored associations between HFHL and cardiovascular-related risk factors/outcomes. Adjusted models indicated elevated diastolic blood pressure in respondents with normal hearing, X¯ = 72.52 (95% confidence interval: 71.85-73.18) compared to the group with bilateral HFHL, X¯ = 70.28 (95%CI: 69.13-71.43), p < 0.05. Average total cholesterol, high-density lipoprotein, low-density lipoprotein and apolipoprotein A1 were elevated in the normal hearing group (p < 0.05). Insulin, high-sensitivity C-reactive protein, and average resting heart rate were elevated in the group with bilateral HFHL, p < 0.05. A stratified analysis by sex- and age, or history of loud occupational noise exposure, did not change the overall results. Although some findings warrant further exploration, the overall analysis did not provide compelling evidence for an association between HFHL and cardiovascular-related biomarkers, or cardiovascular diseases among Canadians aged 20-79 years.

Genetic Susceptibility Study of Chinese Sudden Sensorineural Hearing Loss Patients with Vertigo.

To investigate the genetic causes of sudden sensorineural hearing loss (SSNHL) patients in China. This study focused on analyzing variations of coding sequence of common genes related to deafness, revealing the molecular pathogenesis of sudden deafness from a genomics perspective, discovering molecular markers associated with the onset of deafness, and then supplying prevention to high-risk populations, classifying disease according to accurate etiology, and choosing a much more precision therapy. We retrospectively analyzed the clinical characteristics of 51 patients diagnosed as SSNHL with vertigo treated in the Chinese PLA General Hospital. In this study, mutation screening of 307 nuclear genes and mitochondrial genome responsible for human or mouse deafness was performed on the 51 cases of unilateral sudden deafness patients with vertigo. We identified 51 cases of unilateral sudden deafness, including 2 cases of low-mid frequency hearing impairment, 18 cases of mid-high frequency hearing loss, 11 cases of flat-type hearing loss, and 20 cases of all frequency hearing loss. Among the 51 cases, 8 (15.69%) cases of GJB2 heterozygous variations, 1 (1.96%) case of GJB3 heterozygous variations, 5 (9.8%) cases of SLC26A4 heterozygous variations, 2 (3.92%) cases of COCH heterozygous variations, 14 (27.45%) cases of CDH23 heterozygous variations, 14 (27.45%) cases of OTOF heterozygous variations, 1 (1.96%) case of SLC17A8 heterozygous variations and 2 (3.92%) cases of KCNE1 heterozygous variations. No mtDNA gene variations were identified. SSNHL has some relationship with hereditary in Chinese population, but its complex genetic pathogenic mechanisms need further study.

English

BACKGROUND Hearing loss is a chronic condition, and many cases can be detected in the neonatal period. Recognizing it early is of crucial importance as early auditory rehabilitation would help in child’s comprehensive development. We wanted to assess the prevalence of hearing impairment among high risk newborns admitted to inborn unit of tertiary care centre in Central Kerala and screen for the associated risk factors in these newborns. METHODS Thousand consecutive inborn neonates from Neonatal ICU, Department of Paediatrics, tertiary care centre in Thrissur, Kerala, detected as high risk by Joint Committee on Infant Hearing (JCIH) criteria were enrolled for the study from December 2011 to November 2012 after the approval by Institute’s Ethics Review Board. Risk factor assessment was done before enrolment. A qualified audiologist conducted the test on babies in soundproof chamber. DPOAEs (Distortion Product Otoacoustic Emissions) were used for initial testing after checking ears for debris. Those who failed in the first test were asked to come for a retest after 2 weeks. Those who failed in the retest were asked to report for Brainstem Evoked Response Audiometry (BERA). Those who were diagnosed as having hearing impairment were advised auditory rehabilitation as well as auditory verbal therapy. RESULTS Of the 1000 eligible neonates born in our hospital during the study period (December 2011 to November 2012) 69 were lost to follow up. Among the remaining 931 babies the frequency of hearing impairment was 0.8 %. Among the 931 neonates, 130 had absent response with the first OAE test contributing to 13.9 %. Twenty-one neonates had absent response to second OAE test out of 130 contributing to 16.1 %. The failure rate for second test is 2.2 % of the total population of 931 newborns. Eight of the 21 neonates who were subjected to BERA had severe hearing loss. The prevalence of hearing impairment was 8 per 1000. CONCLUSIONS The prevalence (percentage) of hearing impairment by two staged screening protocol is 0.8 %. Risk factors which were present in these babies were prematurity, low birth weight, low Apgar score, history of exanthematous fever in mother, neonatal jaundice, ototoxic medication history, craniofacial anomalies, and family history of deafness, meningitis and mechanical ventilation. KEYWORDS Otoacoustic Emissions, Brain Stem Evoked Response Audiometry, Risk Factors, Hearing Impairment, Neonates

A real-time wavelet-based algorithm for improving speech intelligibility

A wavelet-based algorithm to improve speech intelligibility is reported. The speech signal is split into frequency sub-bands via a multi-level discrete wavelet transform. Various gains are applied to the sub-band signals before they are recombined to form a modified version of the speech. Dynamic range compression then follows to control the peak amplitude. The sub-band gains are adjusted while keeping the overall signal energy unchanged, and the speech intelligibility under simulated hearing loss conditions and various background interference is enhanced and evaluated objectively and quantitatively using Google Speech-to-Text transcription. For English and Chinese noise-free speech, overall intelligibility is improved, and the transcription accuracy can increase by over 80 percentage points by reallocating the spectral energy toward the mid-frequency sub-bands, effectively increasing the consonant-vowel intensity ratio. This is reasonable since the consonants are relatively weak and of short duration, and are therefore the most likely to become indistinguishable in the presence of background noise or high frequency hearing impairment. For speech already corrupted by noise, improving intelligibility is challenging but still realizable. The proposed algorithm is implementable in real-time and comparatively simpler than previous algorithms. Potential applications include speech transmission, hearing aids, machine listening, and a better understanding of speech intelligibility.

Seven versus Ten Days Antibiotics Course for Acute Pyogenic Meningitis in Children: A Randomized Controlled Trial.

To compare the efficacy and safety of 7 d vs. 10 d empirical antibiotic therapy in cases of acute pyogenic meningitis in children aged 3 mo to 14 y with rapid initial recovery. A total of 96 children aged 3 mo to 14 y with acute pyogenic meningitis were randomized to either 7 d or 10 d therapy on Day 5 of the therapy, if they were in clinical remission and had improving cerebrospinal fluid (CSF) abnormalities. The primary outcome was treatment failure in each group within 10 d of enrolment or relapse of meningitis defined as recurrence of signs and symptoms of meningitis within 2 wk of discharge. Secondary outcome was the presence of sequelae in patient at 30 d and 90 d follow-up post discharge. Out of 111 screened children, 96 patients completed the trial, 48 in each group. There were 7 treatment failures and relapses each in the group receiving 7 d antibiotics while 6 failures and relapses each were seen in 10 d antibiotics group. There was no statistically significant difference in treatment failure in both the groups [2.1 (-0.12-0.16); p = 0.76]. No deaths or significant adverse effects of the drugs occurred during this study. Four cases of nosocomial sepsis were reported with 2 cases in each group. On subsequent 30 d and 90 d follow-up, no statistically significant difference was found between the two groups regarding frequency of hearing impairment, frequency of hydrocephalus [-2.1 (-0.09-0.13); p = 0.65] and various neurological sequelae [6.2 (-0.06-0.19); p > 0.05]. Short course antibiotic therapy may be adequately effective for treatment of acute pyogenic meningitis beyond neonatal age in children with initial rapid recovery.

Asymptomatic Hearing Impairment Frequently Occurs in Early-Onset Parkinson's Disease.

ObjectiveRecent reports of hearing impairment in Parkinson’s disease (PD) have suggested that auditory dysfunction could be a non-motor manifestation of PD. These reports were based on observations of elderly patients for whom presbycusis may, to some extent, have contributed to hearing dysfunction. Therefore, we aimed to explore the auditory functions in younger patients with PD.MethodsWe conducted a case-control study in a relatively younger (< 55 years of age at study time) population of PD patients and healthy volunteers to test whether auditory dysfunction is a significant non-motor dysfunction in PD. Pure tone audiometry (PTA) and brainstem evoked response audiometry (BERA) were performed in all participants.ResultsNone of the patients or controls reported hearing deficits. Fifty-one patients with PD and 50 healthy volunteers who were age- and gender-matched to the patients participated. PTA-detected hearing impairment was found in 64.7% of patients and 28% of controls (p < 0.001) for both low-mid and/or high frequencies. Hearing impairment was more frequent in the younger subgroups of patients than age-matched controls, while the frequency of hearing impairment was similar in older groups of subjects. BERA was not different between patients and controls.ConclusionAsymptomatic auditory dysfunction is a common non-motor manifestation of early-onset PD and more frequent in younger patients, indicating that it may be independent of aging. The mechanism underlying this dysfunction appears to be peripheral, although a central dysfunction cannot be ruled out based on the findings of this study.

Environmental exposure of heavy metal (lead and cadmium) and hearing loss: data from the Korea National Health and Nutrition Examination Survey (KNHANES 2010\u20132013)

BackgroundLead and cadmium have been identified as risk factors for hearing loss in animal studies, but large-scale studies targeting the general human population are rare. This study was conducted to investigate the link between heavy metal concentrations in blood and hearing impairment, using a national population-based survey.MethodsThe study participants comprised 6409 Koreans aged 20 or older, who were included in the Fifth and Sixth Korea National Health and Nutrition Examination Surveys (KNHANES 2010–2013). Hearing impairment was categorized into two types, low- and high-frequency hearing impairment, using pure tone audiometry. Low-frequency hearing impairment was defined as having a binaural average of hearing thresholds for 0.5, 1, and 2 kHz exceeding 25 dB, and high-frequency hearing impairment was defined as having a binaural average of hearing thresholds for 3, 4, and 6 kHz exceeding 25 dB. The blood levels of heavy metals (lead and cadmium) were classified into quartiles. Cross-sectional association between hearing impairment and the level of heavy metals (lead and cadmium) was examined in both sexes. Multivariate logistic regression was used to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs).ResultsAmong men, the prevalence of low- and high- frequency hearing impairment was 13.9% and 46.7%, respectively, which was higher than the prevalence among women (11.8% and 27.0%, respectively). Regarding lead, the adjusted OR of high-frequency hearing impairment for the highest blood level group versus the lowest group was significant in both men (OR = 1.629, 95% CI = 1.161–2.287) and women (OR = 1.502, 95% CI = 1.027–2.196), after adjusting for age, body mass index, education, smoking, alcohol consumption, exercise, diagnosis of diabetes mellitus, hypertension, and noise exposure (occupational, loud, firearm noises). No links were found between blood lead levels and low-frequency hearing impairment, or between blood cadmium levels and low- or high-frequency hearing impairment in either sex.ConclusionsThe present study findings suggest that even exposure to low-level lead is a risk factor for high-frequency hearing loss. A prospective epidemiologic study should be conducted to identify the causal relationship between human health and exposure to heavy metals, and efforts to reduce heavy metal exposure in the general population should continue.

Time course and clinical characterization of cisplatin-induced ototoxicity after treatment for nasopharyngeal carcinoma in a South East Asian population.

The purpose of this study was to characterize the clinical course of hearing loss in patients with nasopharyngeal carcinoma (NPC) and the clinical factors affecting its severity. The time course of hearing loss in patients with NPC was assessed using threshold shift from baseline and Common Terminology Criteria for Adverse Events (CTCAE) grade. In the chemoradiotherapy (CRT) groups, the threshold shift was significantly higher from 3 months at 4 kHz (P = 2.30 × 10-9 , concurrent CRT only) but not within 2 years posttreatment in the radiotherapy (RT) group. The CRT groups had worse CTCAE grades than the RT group (percentage of latest CTCAE grade ≥1: 64.9% vs 29.0%, respectively). Cumulative cisplatin dose and cochlear RT dose significantly affects threshold shifts, especially at high frequencies. Although cisplatin led to high frequency hearing impairment from about 3 months posttreatment, RT conferred no significant hearing impairment in the first 2 years.

Impairment of extra-high frequency auditory thresholds in subjects with elevated levels of fasting blood glucose

This study was performed to assess whether there is an association between elevated Fasting Blood Glucose (FBG) and hearing impairment in Bangladeshi population. A total of 142 subjects (72 with elevated FBG; 70 control) were included in the study. The mean auditory thresholds of the control subjects at 1, 4, 8 and 12 kHz frequencies were 6.35 ± 0.35, 10.07 ± 0.91, 27.57 ± 1.82, 51.28 ± 3.01 dB SPL (decibel sound pressure level), respectively and that of the subjects with elevated FBG were 8.33 ± 0.66, 14.37 ± 1.14, 38.96 ± 2.23, and 71.11 ± 2.96 dB, respectively. The auditory thresholds of the subjects with elevated FBG were significantly (p < 0.05) higher than the control subjects at all the above frequencies, although hearing impairment was most evidently observed at an extra-high (12 kHz) frequency. Subjects with a long duration of diabetes (>10 years) showed significantly (p < 0.05) higher level of auditory thresholds at 8 and 12 kHz, but not at 1 and 4 kHz frequencies, compared to subjects with shorter duration of diabetes (≤10 years). In addition, based on the data of odds ratio, more acute impairment of hearing at the extra-high frequency was observed in diabetic subjects of both older (>40 years) and younger (≤40 years) age groups compared to the respective controls. The binary logistic regression analysis showed a 5.79-fold increase in the odds of extra-high frequency hearing impairment in diabetic subjects after adjustment for age, gender and BMI. This study provides conclusive evidence that auditory threshold at an extra-high frequency could be a sensitive marker for hearing impairment in diabetic subjects.

Headphone-based immersive audio for virtual reality headsets

In this paper, we propose a binaural system for virtual auditory space synthesis and reproduction. We introduce a subjective listening test for head-related transfer function (HRTF) customization and real-time implementation of ambisonic surround sound over headphones. In this test, a listener first selects the closest-matching HRTF dataset from an existing database. The selected HRTF dataset must fulfill the criteria of front-back discrimination and up-down discrimination. Secondly, the selected HRTF dataset is utilized to build a binaural ambisonic system composed of an encoder for synthesizing multiple sound sources, an image-source model for listening-room simulation, an ambisonic rotator responding to head motion in three axes, and a binaural ambisonic decoder. Additionally, we propose a system optimization technique that minimizes computational cost and enhances audio quality. Finally, we present both subjective and objective measurements of the perceived audio quality that were conducted to validate this approach. The audio quality assessment examined the frequency hearing impairment, localization error, and localization blur. The proposed system is especially suitable for mixing and rendering immersive sound in virtual reality.