Normal Hearing Thresholds Research Articles

Study of auditory brainstem response in tinnitus patients with normal hearing

Introduction: Tinnitus is often associated with hearing loss, but it may occur in patients with normal hearing. However, normal hearing thresholds do not exclude cochlear damage.Tinnitus may be initiated by abnormal activity from the peripheral auditory system, but its progress and maintenance is due to the central nervous system involvement. For that reason, Auditory Brainstem Response (ABR) may contribute to clarify the origin of tinnitus.Aim: The aim of this study is to evaluate the ABR waveform amplitude and latencies in tinnitus patients with normal hearing to explore the origin of tinnitus.Results: Auditory brainstem response, recorded using ipsilateral rarefaction click stimuli at 80 dBnHL in 10 normal hearing tinnitus adult patients and 10 matching controls, showed that Wave I amplitude was significantly reduced in the study group when compared to control group. The V/I amplitude ratio was significantly higher in the study group compared to control group. The absolute latency of wave I was significantly increased in the study group compared to control group. Interpeak I-V latency was significantly decreased in the study group compared to control group.Conclusion: Tinnitus sufferers with normal audiometric thresholds might show ABR amplitude changes indicative of cochlear synaptopathy (reduced wave I amplitude) and compensated central responses (no reduction in wave V amplitude). The increased responsiveness of central regions might lead to tinnitus generation secondry to increased spontaneous activity.

Measurement Properties of the Hearing Environments and Reflection of Quality of Life (HEAR-QL) 28-item Questionnaire in Cholesteatoma

We sought to assess the reliability and construct validity of the Hearing Environments and Reflection on Quality of Life Adolescent (HEAR-QL 28) quality of life measure (QoL) in cholesteatoma. Observational. Tertiary referral center. One hundred seventeen patients with a diagnosis or history of cholesteatoma completed HEAR-QL 28. In addition to patients within the age range recommended for HEAR-QL 28 (13-18 yr), patients under 13 years old who were able to complete HEAR-QL 28 without parental assistance were included. Completion of HEAR-QL 28 QoL measure. HEAR-QL 28 score, four tone average pure tone audiogram hearing threshold and categorical classification of hearing loss as mild, moderate, and severe. HEAR-QL 28 did not demonstrate discriminative ability on the basis of audiometric threshold, but did discriminate between participants hearing normally (four tone average pure tone audiogram <30 dB HL) (HEAR-QL 86/100) after cholesteatoma surgery from those with unilateral hearing loss (HEAR-QL 73/100) (p < 0.001). Those with unilateral loss could in turn be differentiated from those with bilateral loss (HEAR-QL 60/100) (p < 0.006). HEAR-QL 28 is valid measure of QoL in cholesteatoma with no evidence of redundancy and excellent internal consistency. The importance of considering QoL impact of cholesteatoma is highlighted by 17% of participants reporting the normality or abnormality of their hearing differently from their audiometric threshold. The HEAR-QL 28 provides insight into the ability to cope with their hearing environment in a specific environment.

Hidden Hearing Loss: Mixed Effects of Compensatory Plasticity

Hidden hearing loss manifests as speech perception difficulties with normal hearing thresholds. A new study shows that neural compensation induced by this disorder may actually improve speech perception under narrow conditions within an overall profile of degradation.

Audiological and otologic manifestations of glutaric aciduria type I

BackgroundGlutaric aciduria type 1 (GA-1) is a rare disease connected with speech delay and neurological deficits. However, the audiological and otologic profiles of GA-1 have not yet been fully characterized. To our knowledge, this is the largest study of comprehensive audiological and otologic evaluation in patients with GA-1 to date.MethodsThirteen patients diagnosed with GA-1 between January 1994 and December 2019 with audiological, radiological and genetic manifestations were retrospectively analyzed. Hearing tests were performed in all patients. MRI was performed for radiological evaluation.ResultsHearing loss was found in 76.9% (10/13) of GA-1 patients, including slight hearing loss in 46.1% (6/13) of patients, mild hearing loss in 15.4% (2/13) of patients, and moderate hearing loss in 7.7% (1/13) of patients. Normal hearing thresholds were seen in 23% (3/13) of patients. Patients with intensive care unit (ICU) admission history showed significantly worse hearing than those without (29.17 ± 12.47 vs 13.56 ± 3.93 dB HL, 95% CI 2.92–24.70, p = 0.0176). One patient had moderate sensorineural hearing loss and a past history of acute encephalopathic crisis. No usual causative gene mutations associated with hearing loss were found in these patients. MRI showed a normal vestibulocochlear apparatus and cochlear nerve. One patient with extensive injury of the basal ganglia on MRI after acute encephalopathic crisis was found to have moderate sensorineural hearing loss. Two patients with disability scores above 5 were found to have mild to moderate hearing impairment. No obvious correlation between macrocephaly and hearing loss was found.ConclusionA high prevalence of hearing impairment is found in GA-1 patients. Adequate audiological evaluation is essential for these patients, especially for those after encephalopathic crises or with ICU admission history.

Characteristics of Chronic Suppurative Otitis Media (CSOM) patients who underwent tympanoplasty surgery at Sanglah General Hospital for the period 2017 - 2019

Background: One way to deal with deafness from Chronic Suppurative Otitis Media (CSOM) is middle ear reconstruction surgery known as tympanoplasty. The success of surgery is when complete eradication of the disease is possible as well as hearing improvement. This study aims to evaluate the characteristics of chronic suppurative otitis media patients who underwent tympanoplasty surgery at Sanglah General Hospital for the period 2017 – 2019.Methods: A retrospective descriptive study was conducted through secondary data from the medical records of CSOM patients who had undergone tympanoplasty surgery at Sanglah General Hospital in Denpasar during the January 2017 - December 2019 period. Variables assessed in this study were age, sex, address of residence, infected side, perforation surface area, CT-scan, culture, surgical findings, graft type and antibiotic therapy, post tympanoplasty tympanic membrane perforation condition, audiometry results before and after undergoing tympanoplasty. Data were analyzed using SPSS version 20 for Windows.Results: Most of the respondents were male (53.3%), aged 46 - 55 years (26.7%), and living in Denpasar (30.0%). Based on the ear side, the most infected were unilateral (53.3%) and the subtotal perforation surface area (78.3%). No visible abnormalities (40.0%) were the most cases on the CT-Scan, following by the Pseudomonas aeruginosa (21.7%) infection and surgical findings in the form of tympanic membrane perforation only (55.0%). Based on the 3 months post tympanoplasty condition, it was found that the perforation had closed (83.3%), normal audiometric results (38.3%), and a degree of improvement in the hearing threshold after undergoing tympanoplasty was found to be mostly 5-10 dB (48.3%).Conclusion: CSOM patients who underwent tympanoplasty surgery were mostly men, aged 46-55 years, unilateral, subtotal perforation, and no CT scan abnormalities. In comparison, the membrane perforation condition 3 months post tympanoplasty was closed, mild deafness before tympanoplasty, normal degree of deafness after tympanoplasty, and the average mean hearing threshold improvement was 5 - 10 dB.

REPLY TO THE LETTER TO THE EDITOR: EARLY DETECTION OF HIGH-FREQUENCY PRESBYCUSIS AMONG NORMAL HEARING INDIVIDUALS.

In Reply: We thank you for the opportunity to respond to the comments raised on our article entitled “Early Detection of High-frequency Presbycusis Among Normal Hearing Individuals.” From our study, 62.4% of the respondents were female (1). If we were to divide the sex according to the age group, female accounts for 62.0% (93 of 150 participants) and 63.6% (35 of 55 participants) respectively for the young age and older age group. Therefore, with a similar ratio of male to female participants in both age groups, we can conclude that sex does not affect the audiometric thresholds. Regarding the smoking status, there were more than 90% of the participants in our study who were nonsmoker (1). Besides the small percentage of the smoker, they were equally distributed in both groups as well (9.3% in the young and 7.3% in the older age group). However, as a study has established that oxidative stress plays a crucial role in the development of age-related hearing loss (2), further evaluation can be done to confirm its effect at the higher frequency. Our participants were mostly Malay (90.7%). The proportion of other ethnicity was small as less than 8% of the total were shared among Chinese, Indians, and others. The percentage reflects the racial distribution of our local community. Therefore, the ethnicity factor can be negligible. In our study, we had included only those with normal hearing threshold based on conventional pure-tone audiometry. In other words, we had already excluded those who were having noise-induced hearing loss and presbycusis. Notch at the frequencies of 3, 4, or 6 kHz is the sign in the early stage of noise-induced hearing loss (3). The results of higher prevalence of high-frequency presbycusis with increasing in age are not beyond expectation. The more important aspect of the study was to highlight the possibility of using high-frequency DPOAE in detecting presbycusis.

Postoperative controls of ventilation tubes in children by general practitioner or otolaryngologist? Study protocol for a multicenter randomized non-inferiority study (The ConVenTu study)

BackgroundOtitis media with effusion is the major cause of acquired hearing problems in children. Some of the affected children need surgery with ventilation tubes in the tympanic membrane to reduce ear complaints and to improve hearing, middle ear function, and health-related quality of life. This is one of the most common ambulatory surgeries performed on children. Postoperative controls are needed to assess that the tubes are functional, to evaluate whether hearing loss has been improved, and to handle potential complications. The follow-up may continue for years and are usually done by otolaryngologists. Nevertheless, there exist no evidence-based guidelines concerning the level of expertise needed for postoperative controls of the ventilation tubes. The aim of this protocol is to describe the ConVenTu study that evaluates whether postoperative controls performed by general practitioners (GPs) represent a safe and sufficient alternative to controls performed by otolaryngologists.Methods/designMulticenter randomized non-inferiority study conducted in clinical settings in seven hospitals located in Norway. Discharged children with ventilation tubes, aged 3–10 years, are allocated randomly to receive postoperative controls by either an otolaryngologist at the hospital where they had ventilation tube surgery or their regular GP. Study participants are enrolled consecutively until 200 patients are included in each group. Two years after surgery, we will compare the pure tone average of hearing thresholds (primary endpoint) and middle ear function, complication rate, health-related quality of life and the parents’ evaluations of the postoperative care (secondary endpoints).DiscussionThis protocol describes the first randomized non-inferiority study of GPs performing postoperative controls after surgery with ventilation tubes. Results from this study may be utilized for deriving evidence-based clinical practice guidelines of the level of postoperative controls after ventilation tube surgery which is safe and sufficient.Trial registrationClinicalTrials.govNCT02831985. Registered on 13 July 2016

Comparison among Three Different Steroid Therapies for Idiopathic Sudden Sensorineural Hearing Loss

Background and Objectives The optimal dose or type of systemic steroid for treating idiopathic sudden sensorineural hearing loss (ISSNHL) is unclear. Herein, we compare the efficacy of three steroid treatment protocols.Subjects and Method We reviewed the medical records of 140 adult ISSNHL patients from a tertiary medical center. The patients were divided into three groups based on their treatment regimen: Group 1 received intravenous 10 mg/day dexamethasone combined with intratympanic (IT) steroid injection, followed by prednisolone for 5 days after discharge; Group 2 received 10 mg/day dexamethasone for 5 days, followed by 5 mg/day for 5 days over a 10-day hospitalization period; and Group 3 received 10 mg/day dexamethasone combined with IT steroid injection during a 5-day hospital stay, followed by 5 mg/day dexamethasone for 5 days after discharge. The hearing thresholds were measured using an automatic audiometer at 0.5, 1, 2, 3, 4, and 8 kHz. Hearing recovery on Day 90 was categorized according to Siegel’s criteria.Results Univariate and multivariate analyses showed that patients in Group 3 had the lowest hearing thresholds, and the best results for speech reception threshold and speech discrimination scores. The impact of favorable thresholds in Group 3 was better among patients with a baseline average hearing threshold of ＜70 dB. Complete recovery was more likely in Group 3 than in the other groups, based on the odds ratios.Conclusion Administration of dexamethasone-based systemic steroid combined with IT steroid injection and a relatively long hospitalization period produced the most favorable result.

Tinnitus Is Associated With Extended High-frequency Hearing Loss and Hidden High-frequency Damage in Young Patients.

Objectives:To analyze the results of extended high-frequency (EHF) and high-frequency hearing tests in young patients with tinnitus who show normal response in conventional pure-tone audiometry (PTA), and to explore the correlation between tinnitus and hearing loss (HL).Study Design:A case–control study.Setting:A Tertiary Eye Ear Nose & Throat Hospital of China.Participants:Patients with tinnitus, aged 18 to 35 years old, and with normal conventional PTA (125 Hz–8 kHz) were enrolled in the tinnitus group. Volunteers without tinnitus of the same age were enrolled in the control group.Main Outcome Measures:The incidence of EHF-HL and the hearing thresholds at each frequency, as well as the distribution of maximum HL frequency and edge frequency in all participants were compared.Results:In total, 28 cases (43 ears) were enrolled in the tinnitus group and 34 cases (68 ears) in the control group. The incidence of EHF-HL, average hearing threshold of each frequency ranging from 4 to 16 kHz, and the maximum hearing threshold were significantly higher in the tinnitus group. The edge frequency in the tinnitus group was lower than that in the control group (10.4 ± 3.1 kHz versus 12.3 ± 2.5 kHz, p = 0.010). The dominant tinnitus pitch in cases whose EHF was impaired was positively correlated with the hearing-level loudness of tinnitus (r = 0.627, p < 0.001).Conclusion:Patients with tinnitus and normal hearing in conventional PTA showed signs of EHF-HL and hidden damage in the high-frequencies more easily. EHF hearing tests and the follow-up of HF hearing tests are recommended to facilitate early detection of hearing impairment for timely intervention.

Within-Subject Comparisons of the Auditory Brainstem Response and Uncomfortable Loudness Levels in Ears With and Without Tinnitus in Unilateral Tinnitus Subjects With Normal Audiograms.

To evaluate whether cochlear synaptopathy is a common pathophysiologic cause of tinnitus in individuals with normal audiograms. Prospective study. Tertiary referral center. We enrolled 27 subjects with unilateral tinnitus and normal symmetric hearing thresholds, and 27 age- and sex-matched control subjects with normal symmetric hearing thresholds. We measured 1) the amplitudes of waves I and V with 90 dB nHL click stimuli in quiet conditions; 2) the latency shift of wave V with 80 dB nHL click stimuli in background noise, varying from 40 dB HL to 70 dB HL; and 3) uncomfortable loudness levels (UCLs) at 500 Hz and 3000 Hz pure tones. There were no significant differences in the wave V/I amplitude ratio or the latency shift in wave V with increasing noise levels among the tinnitus ears (TEs), nontinnitus ears (NTEs), and control ears. There were no significant differences in UCLs at 500 Hz or 3000 Hz between TEs and NTEs, but the UCLs were lower in TEs (mean 111.3 dB or 104.1 dB) and NTEs (mean 109.4 dB or 100.6 dB) than in control ears (mean 117.9 dB or 114.1 dB, p < 0.017). No subject met our criteria for cochlear synaptopathy or increased central gain in terms of all three parameters. Based on these results for UCL, increased central gain is a major mechanism of tinnitus in humans with normal audiograms. However, this compensatory mechanism for reduced auditory input may originate from other pathophysiologic factors rather than from cochlear synaptopathy.

Otoacoustic emissions and contralateral suppression in tinnitus sufferers with normal hearing

BackgroundThe general consensus on the role of hearing loss in generating tinnitus is not relevant in tinnitus patients with normal hearing thresholds. One source of tinnitus may be related to damage to outer hair cells (OHC) of the cochlea. If the OHC of the human cochlea are to be involved in the generation of tinnitus, testing of Otoacoustic emissions (OAE) could provide a reliable means of recording OHC dysfunction. We investigated the role of OHC and cochlear efferent system in tinnitus development in normal hearing ears through studying of Distortion Product Otoacoustic Emissions (DPOAE) and Transient Evoked Otoacoustic Emissions (TEOAE) amplitudes, contralateral suppression amplitudes and suppression value in 15 normal hearing tinnitus patients and 15 control subjects.ResultsMean f2 DPOAE amplitudes and contralateral suppression were significantly lower in tinnitus group compared to controls for all frequencies from 1001 to 6348 Hz. Suppression values of DPOAEs revealed lower but not significant difference between tinnitus and control groups for all frequencies except 1587 and 6348 Hz. TEOAE amplitudes and contralateral suppression were significantly lower in tinnitus groups for all frequencies from 1000 to 4000 Hz compared to the control group. Suppression value of TEOAEs revealed no significant difference between the two groups for all frequencies except 3000 and 4000 Hz were significantly lower in the tinnitus group compared to the control group.ConclusionsNormal hearing manifested by pure tone audiometry in non-vascular tinnitus sufferers does not exclude OHC and/or cochlear efferent pathology.

Modulation of hearing function following the downgrading or upgrading of endolymphatic hydrops in Meniere's disease patients with endolymphatic duct blockage.

The present study was to investigate the dynamics of endolymphatic hydrops (EH) and hearing function, and explore whether the hearing loss is caused by EH alone and whether the hearing function can be modulated by changes in the EH. The extent of EH visualized by gadolinium (Gd)-enhanced inner ear magnetic resonance imaging, hearing thresholds and the summating potential/action potential ratio (-SP/AP ratio) of electrocochleography (ECochG) were recorded prior to and following surgery in 22 patients with intractable Meniere’s disease (MD) who underwent endolymphatic duct blockage (EDB). The difference value of the hearing threshold and -SP/AP ratio was significantly positively correlated with the difference value of the endolymph to vestibule-volume ratio (EVVR) and grading of cochlear hydrops between prior to and following surgery. Among patients with a decreased EVVR, the average hearing threshold and -SP/AP ratio was significantly decreased following surgery, as compared to that prior to surgery. Six out of seven patients with a hearing improvement (≥10-dB decline) and 4/5 patients with a negative conversion of EcochG showed downgrading of their hydrops in the cochlea and/or vestibule. By contrast, among patients with an increased EVVR, the average hearing threshold and -SP/AP ratio tended to increase following EDB, as compared with that prior to surgery. One out of two patients with a hearing deterioration (≥10-dB elevation) showed upgrading of her hydrops in both cochlea and vestibule. The present results showed the downgrading of cochlear and/or vestibular hydrops accompanied by the downregulation of the hearing threshold and -SP/AP ratio of EcochG, as well as the upgrading of cochlear and/or vestibular hydrops that tended to upregulate the hearing threshold and -SP/AP ratio of EcochG; this suggested that hearing loss is likely to be caused by hydrops and that the impaired hearing function be modulated by changes in the hydrops.

Age-Related Deficits in Electrophysiological and Behavioral Measures of Binaural Temporal Processing.

Binaural processing, particularly the processing of interaural phase differences, is important for sound localization and speech understanding in background noise. Age has been shown to impact the neural encoding and perception of these binaural temporal cues even in individuals with clinically normal hearing sensitivity. This work used a new electrophysiological response, called the interaural phase modulation-following response (IPM-FR), to examine the effects of age on the neural encoding of interaural phase difference cues. Relationships between neural recordings and performance on several behavioral measures of binaural processing were used to determine whether the IPM-FR is predictive of interaural phase difference sensitivity and functional speech understanding deficits. Behavioral binaural frequency modulation detection thresholds were measured to assess sensitivity to interaural phase differences while spatial release-from-masking thresholds were used to assess speech understanding abilities in spatialized noise. Thirty adults between the ages of 35 to 74 years with normal low-frequency hearing thresholds were used in this study. Data showed that older participants had weaker neural responses to the interaural phase difference cue and were less able to take advantage of binaural cues for speech understanding compared to younger participants. Results also showed that the IPM-FR was predictive of performance on the binaural frequency modulation detection task, but not on the spatial release-from-masking task after accounting the effects of age. These results confirm previous work that showed that the IPM-FR reflects age-related declines in binaural temporal processing and provide further evidence that this response may represent a useful objective tool for assessing binaural function. However, further research is needed to understand how the IPM-FR is related to speech understanding abilities.

Serum per- and polyfluoroalkyl substances in relation to hearing loss

Background: Studies have shown that per- and polyfluoroalkyl substances (PFAS) are potential ototoxicants. However, no epidemiologic study has been conducted. We conducted a cross-sectional study to examine the associations of PFAS with hearing impairment. Methods: This study included data from the National Health and Nutrition Examination Survey (NHANES) 1999-2000, 2003-06, and 2009-14 because only these year cycles contained all the information we needed. Perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured in serum samples. Participants were divided into quartiles for each PFAS. Air conduction pure-tone audiometry was administered. Hearing impairment was defined as an average hearing threshold of more than 25dB at each hearing frequency. We assessed the relation of serum PFAS with hearing impairment by the generalized linear mixed model with a logit link and binary distribution. Tests for linear trend across quartiles of serum PFAS were conducted using the median serum PFAS in each quartile as a continuous variable. Results: A total of 2525 participants (women = 53.4%) aged 20 or above were included into the final analysis. After adjusted for age, sex, body mass index, education, ethnicity group, family income, and sampling weights, we found positive correlations between PFOA and hearing impairment at 2000 Hz (p-trend = 0.02) and 3000 Hz (p-trend = 0.01); between PFOS and hearing impairment at 2000 Hz (p-trend &lt; 0.01) and 3000 Hz (p-trend = 0.01); between PFNA and hearing impairment at 3000 Hz (p-trend &lt; 0.01), 4000 Hz (p-trend &lt; 0.01), and 8000 Hz (p-trend = 0.03); between PFHxS and hearing impairment at 500 Hz (p-trend = 0.02), 1000 Hz (p-trend = 0.01), 2000 Hz (p-trend &lt; 0.01), and 3000 Hz (p-trend = 0.03). Conclusion: Background serum PFASs are correlated with hearing impairment in the United States adult population.

Prevalence of extended high-frequency hearing loss among adolescents from two rural areas in Colombia

Objective Worldwide research trends on the prevalence of hearing loss within young rural populations are scarce. Current evidence suggests extended high-frequency audiometry could be a sensitive predictor to detect subclinical hearing loss. This study aimed to determine the prevalence of hearing loss through conventional pure tone (0.25–8 kHz) and extended high-frequency (9–20 kHz) audiometry tests in a group of adolescents aged 13 to 19 years old from two rural areas of Colombia. A sociodemographic and associated factor for hearing loss questionnaire was applied. Design Cross-sectional study. Study Sample Three hundred sixty-six adolescents aged 13 to 19 years old from two rural municipalities in Colombia: Soracá, and Palmas del Socorro. Results Hearing loss prevalence assessed through pure tone audiometry was 3.28% in right ears and 3.83% in left ears while through extended high-frequency audiometry was 14.21% and 13.11%, respectively. Associated factors found by the logistic regression were age (OR: 1.36; CI 95% 1.13-1.64) and obesity (OR: 3.74; CI 95% 1.07-13.11). Conclusions Using 15 dB as the normal hearing threshold parameter for audiometric frequencies, our results suggest that extended high-frequency hearing loss is already widespread among rural adolescents. This highlights the need for research on extended high-frequency audiometry in rural school-aged children.

Descriptive Patterns of Deafness Among Pre-School Saudi Children Aged Two to Five Years Visiting Neurology Clinic From 2012 to 2017.

BackgroundEarly childhood years are very important and crucial periods for developing different developmental milestones. Hearing loss is considered to be one of the most commonly detectable problems, which often goes unnoticed or not given proper attention due to the lack of screening modalities or the inability of parents or guardians to recognize it in early stages. Therefore, it is necessary to determine the pattern of differences pertaining to hearing loss among pre-school children of various age groups to better approach this issue in a systemic and fundamental manner, so that better care and treatment can be provided to children suffering from deafness.MethodsThis study involved a descriptive, retrospective chart review in two hospital settings, and it was conducted at the department of physiology (neurophysiology) of King Abdulaziz and King Khalid University Hospitals at the King Saud University (KSU) in Riyadh during the period of 2012-2017. A total of 324 pre-school Saudi children from the age of two to five years were involved and tested by brainstem auditory evoked potentials (BAEPs) to assess deafness.ResultsA total of 324 patients underwent the BAEP test; of them, 199 (61.4%) were males and 125 (38.6%) were females. Regarding the age groups, the most common age group was that of two-year-olds with 117 (36.1%) participants, followed by three-year-olds with 80 (24.7%) children, four-year-olds with 73 (22.5%) patients, and five-year-olds with 54 (16.7%) participants. Furthermore, there were 220 (67.9%) patients with sensorineural hearing loss (SNHL), 92 (28.4%) with conductive hearing loss (CHL), four (1.2%) with mixed hearing loss (MHL), and eight (2.5%) with normal audiometry. The normal hearing threshold was determined to be 20 dB, and the mean value for the hearing threshold of the SNHL in the right ear was found to be 43.45 ± 25.85, while the left-ear mean value was 44.54 ± 28.78. The mean value of the hearing threshold in CHL of the right ear was 50.96 ± 22.23, while that of the left ear was 47.85 ± 22.74. Lastly, the mean value of the hearing threshold in MHL of the right ear was 80.00 ± 21.21, while that of the left ear was 73.75 ± 18.87.ConclusionSNHL was the most common type (67.9%) of pre-school hearing loss in Saudi Children attending the neurophysiology clinic at KSU hospitals between 2012-2017, while MHL constituted the most severe cases.

Hidden Hearing Loss Impacts the Neural Representation of Speech in Background Noise

SummaryMany individuals with seemingly normal hearing abilities struggle to understand speech in noisy backgrounds. To understand why this might be the case, we investigated the neural representation of speech in the auditory midbrain of gerbils with “hidden hearing loss” through noise exposure that increased hearing thresholds only temporarily. In noise-exposed animals, we observed significantly increased neural responses to speech stimuli, with a more pronounced increase at moderate than at high sound intensities. Noise exposure reduced discriminability of neural responses to speech in background noise at high sound intensities, with impairment most severe for tokens with relatively greater spectral energy in the noise-exposure frequency range (2–4 kHz). At moderate sound intensities, discriminability was surprisingly improved, which was unrelated to spectral content. A model combining damage to high-threshold auditory nerve fibers with increased response gain of central auditory neurons reproduced these effects, demonstrating that a specific combination of peripheral damage and central compensation could explain listening difficulties despite normal hearing thresholds.

The impact of tinnitus on working memory capacity

Objective To determine if tinnitus was related to working memory (WM) in adults and if tinnitus handicap was related to WM in adults with tinnitus. Design Two groups, cross-sectional design. Study samples 76 adults forming a tinnitus group (n = 38) and a control group (n = 38). Each group included 19 adults with normal hearing and 19 adults with hearing loss matched for age, sex and educational backgrounds. All participants completed the visual n-back test; pure tone audiometry (0.125–16 kHz); and the Hospital Anxiety and Depression Scale (HADS). Tinnitus sufferers also completed the Tinnitus Handicap Inventory (THI). Results For all participants, tinnitus was not related to WM scores when corrected for hearing thresholds, anxiety, and depression. The corrections for best ear high-frequency pure-tone average hearing threshold (BEHFPTA: 10, 12.5, 14 and 16 kHz) were significant. For tinnitus sufferers, THI was related to WM scores in the easiest n-back condition, and BEHFPTA was related to WM scores in the easiest and the hardest n-back condition. Conclusion Tinnitus was not related to WM scores. Tinnitus handicap was related to some WM scores in tinnitus sufferers. Further investigation of the possible relationship between high-frequency hearing and WM is warranted.

Development and validation of a digits-in-noise hearing test in Persian

Objective The prevalence of unrecognised and late-diagnosed hearing loss is higher in low- and middle-income than in high-income countries, due in part to lack of access to hearing services. Because hearing screening is important for early identification of hearing loss, development of an accessible, self-screening test that can detect hearing loss reliably and quickly would provide significant benefits, especially for underserved populations. This study aimed to develop and validate a new version of the digits-in-noise (DIN) test for Persian speaking countries. Design Recordings of Persian digits 0–9 were binaurally presented in broadband speech-shaped noise. Using fitted speech intelligibility functions, digits were homogenised to achieve equal perceptual difficulty across stimuli. The evaluation was established by reference to existing English DIN tests. Study sample Thirty Persian speaking young adults with normal hearing thresholds (≤20 dB HL, 0.25–8 kHz). Results Speech intelligibility functions produced a mean speech reception threshold (SRT) of −7.7 dB, corresponding closely to previously developed DIN tests. There was no significant difference between test and retest SRTs, indicating high reliability of the test. Our findings suggest that language-specific factors need to be considered for cross-language comparison of DIN-SRTs. Conclusion This study introduces a convenient tool for future hearing screening in Persian speaking countries with limited access to audiology services.

Effects of SoundBite Bone Conduction Hearing Aids on Speech Recognition and Quality of Life in Patients with Single-Sided Deafness.

Objectives To analyze the clinical application of SoundBite bone conduction hearing aids by assessing the improvement of speech recognition and the scores of the benefit scale questionnaire for patients with single-sided deafness (SSD). Design Nine patients aged 24 to 61 years with SSD for more than 3 months were enrolled in this study. The patients could understand and repeat Mandarin and have good compliance with the study. The measurements were evaluated before and after one month of wearing hearing aids using the pure tone audiometry threshold, speech recognition in quiet and in noise, and the Glasgow Benefit Inventory (GBI) benefit scale score. Results Pure tone audiometry results showed that the average hearing threshold of good ears and bad ears was 11.4 ± 2.6 dB HL and 89.9 ± 6.4 dB HL, respectively. The average hearing threshold of bad ears after wearing hearing aids was 23.5 ± 9.0 dB HL. Statistical analysis showed that the hearing improvement for the bad ears after wearing hearing aids was significant. The speech audiometry results showed that the disyllable word recognition score of the bad ears in quiet increased significantly at 50 dB SPL by 40 ± 12 percentage points and at 65 dB SPL by 71 ± 15 percentage points. As for the speech recognition in noise, when the signal sound came from the bad ear side and the noise from the good ear side (SSSDNAH), the speech recognition score (SRS) significantly increased by 17 ± 6 and 9 ± 4 at a signal-to-noise ratio (SNR) of -2 dB and -5 dB, respectively, after wearing the hearing aids. When the signal sound came from the front of the patient and the noise from the bad ear side (S0NSSD), the SRS scores were reduced by 5 ± 5 and 7 ± 5 percentage points at SNR equal to -2 dB and -5 dB, which was significantly different from that before wearing the hearing aids. When the signal and noise both came from the front of the patients (S0N0), the SRS was not significantly increased by 5 ± 4 percentage points at SNR equal to -2 dB compared to before wearing hearing aids. However, the SRS was significantly increased by 5 ± 2 percentage points at SNR equal to -5 dB compared to before wearing hearing aids. The average total GBI score was 31 ± 12 for the nine patients, with an average score of 32 ± 10, 31 ± 8, and 30 ± 7 for general conditions, social support, and physical health, respectively. The results of the questionnaires showed that patients' quality of life was improved after wearing SoundBite bone conduction hearing aids. Conclusions SoundBite bone conduction hearing aids are a good choice for patients with SSD, as it could improve the speech recognition ability of patients both in a quiet and noisy environment and improves the quality of life after wearing hearing aids.