Differences In Hearing Thresholds Research Articles

Impact of Site, Size and Duration of Tympanic Membrane Perforation on Hearing Loss and Postsurgical Outcome.

This paper aims to assess correlation of site, size and duration of tympanic membrane perforation with hearing loss using pure tone audiogram and surgical outcome in terms of above parameters. The present study was conducted on 100 patients in Department of ENT and HNS, SMGS Hospital, Government Medical College Jammu during a time period of November 2018 to October 2019. All the patients with age 15-60years who presented with tympanic membrane (pars tensa) perforation were included in the study. According to the size of perforation, mean pure tone threshold in group I was 20.87 ± 3.86dB, in group II was 26.45 ± 6.08dB and in group III was 32.6 ± 5.56dB. The difference in hearing threshold between all the three groups was significant statistically. In terms of site, group E had maximum hearing threshold (34.67 ± 4.20dB), followed by group B (32.71 ± 5.88dB). Group A had the lowest hearing threshold of 24.99 ± 6.21dB. The difference between hearing thresholds of group B perforations and group A perforations was statistically significant (p < 0.05). However, the difference between group E and group B was insignificant. This study has shown significant correlation between the size and the site of the perforation to the degree of hearing loss. The bigger the perforation, the greater the hearing loss. The central perforations were associated with more hearing loss than posterior perforations, thus refuting the hypothesis that site and size of a tympanic membrane perforation does not affect the degree of conductive hearing loss. This study did not show any correlation between duration of disease and degree of hearing loss. Surgical and audiometric results obtained in this study can be accepted as satisfactory and as expected by the literature.

A novel approach to initial hearing assessment

Objective: justifying the possibility of using frequency-based hearing research via the web application ‘Automated System for Initial Hearing Assessment’. Materials and methods. The study was carried out at the Department of Otorhinolaryngology of the Samara State Medical University clinics in October 2019. It involved 91 patients 17 to 73 years old (average age 48±14.6 years). All study participants were divided into two age groups: Group I 17-59 years old), and Group II (over 60 years old). Patients were required to undergo two hearing assessment tests: using the Interacoustics AC-40 clinical audiometer and using our web application ‘Automated System for Initial Hearing Assessment’ (patent No. 2019664671). Results. The maximum difference in average hearing thresholds between pure-tone threshold audiometry and the web application in Group I was 3.3 dB at a frequency of 2 kHz on the right and 3.2 dB at frequencies of 2 and 4 kHz on the left; in Group II, it constituted 4.7 and 3.5 dB at 1 and 2 kHz, on the right, correspondingly, and 7.2 dB at 4 kHz on the left. The presented data were evaluated using the Cohen’s kappa coefficient, which confirmed high level of agreement between the results obtained using the clinical audiometer vs. our original web application. Conclusion. Based on the obtained results, a conclusion was made about the possibility of using the original web application for the initial hearing express assessment in general practice in conditions of limited availability of audiological care.

Hearing loss in patients with systemic lupus erythematosus: A systematic review and meta-analysis.

To determine the prevalence of hearing loss (HL) in patients with systemic lupus erythematosus (SLE), describe frequency-specific hearing threshold changes in this patient population as compared to age-matched control, and compare the clinical and serological profiles of patients with SLE with and without HL. A systematic review querying four databases (PubMed, Web of Science, Scopus, and Cochrane) was performed. Meta-analysis of available data was performed to determine the overall prevalence and odds ratio (OR) of HL, and compare mean differences in frequency-specific hearing thresholds between patients with SLE and control. Additionally, meta-analysis of proportions allowed for comparison of disease features present in patients with SLE with and without sensorineural HL. This review included 17 studies reporting on 1326 patients (635 with SLE and 691 control). The pooled prevalence of HL in patients with SLE was 27%. In comparison to control, patients with SLE had a significantly higher odds of HL (OR 14.6, 95% CI: 8.5 to 25.0). Mean air-conduction hearing thresholds in patients with SLE were significantly elevated relative to control at 125 and 250 Hz. Mean bone-conduction hearing thresholds were significantly elevated in patients with SLE across all measured frequencies except at 3000 and 6000 Hz compared to control. Disease features did not significantly differ between patients with SLE with and without HL. Compared to age-matched control, patients with SLE have increased odds of HL, which primarily manifests at low frequencies. Therefore, this patient population requires greater audiologic attention.

Outcome of cochlear implantation in the worse ear of post-lingual asymmetric hearing loss: elucidation of prognostic markers

Background Specific correlations between the outcomes of cochlear implantation (CI) and hearing thresholds of the both ears in post-lingual asymmetric hearing loss (AHL) patients were not clear. Aims/Objectives To identify the variables influencing the outcome of CI in post-lingual AHL patients. Method We included 18 adult subjects who had CI in the worse ear due to post-lingual AHL with average hearing asymmetry of 36 dB. Speech perception scores were evaluated in the sound field with hearing aid on the better ear before CI, and with the cochlear implant in the worse ear at 3, 6, and 12 months after CI switch-on. Results Average increases in phonetically balanced word score, spondee word score, and everyday sentence score at 12 months from CI switch-on compared with those before CI were 38.9%p, 46.2%p, and 52.4%p, respectively. Multiple linear regression analysis showed that speech perception scores were negatively influenced by age at implantation and hearing threshold difference of both ears (HTD-Both) itself, rather than the worse or better ear hearing thresholds. Conclusions and significance Post-lingual AHL subjects with high average hearing asymmetry can benefit from CI in the worse ear, while CI outcomes can be adversely influenced by HTD-Both and age at implantation both in the short- and long-term follow-up.

Extended high-frequency audiometry in healthy adults with different age groups

BackgroundIt was well-documented that extended high-frequency (EHF, above 8 kHz) hearing test could be more sensitive comparing with the conventional measurement on frequency below 8 kHz, regarding the early prediction of auditory damage in certain population. However, hardly any age-specific thresholds of EHF in population with normal hearing ability were observed. This study aims to monitor the age-dependent hearing thresholds at EHF (from 9 to 20 kHz) in healthy hearing population.MethodsA total of 162 healthy participants (from 21 to 70 years) with normal conventional pure tone audiograms were recruited and separated into five groups by age. Conventional pure tone average was performed with frequencies from 0.25 to 8 kHz under air conduction and from 0.25 to 4 kHz under bone conduction. EHF audiometry from 9 to 20 kHz was determined under air conduction.ResultsThe effects of aging on hearing were evident at frequencies above 4 kHz. The hearing thresholds of EHF were less than 26 dB HL before 30 years-olds. Hearing abilities in EHF were deteriorated starting from the 31 ~ 40 group and were most obvious in the 51 ~ 60 group and the 61 ~ 70 group with the maximum thresholds of 75 dB HL. Sensitivity of EHF was inversely proportional to the frequency within each age group, and to age among groups. Subjects under 30 years old were totally responsive up to 16 kHz, and 52.2% could respond to 20 kHz. Meanwhile, no responsiveness was recorded to 20 kHz in the 51 ~ 60 group and even to 18 kHz in the 61 ~ 70 group. No gender differences in hearing threshold was observed within each age group, except an obvious decline at frequencies of 4, 6, 8, and 9 kHz in male participants of the 41 ~ 50 group.ConclusionsHearing thresholds at EHF from 9 to 20 kHz were more sensitive than at frequencies below 8 kHz for hearing measurement, and aging inversely affected hearing ability at EHF in healthy population. Hearing thresholds at EHF deteriorated with age and raising frequency, while the upper frequency limit decreased with aging.Graphical abstract

Investigating the relation between minimum masking levels and hearing thresholds for tinnitus subtyping.

Heterogeneity of tinnitus imposes a challenge for its treatment. Identifying tinnitus subtypes might help to establish individualized diagnosis and therapies. The minimum masking level (MML) is a clinical tool defined as the minimum intensity of a masking sound required to cover tinnitus. Understanding the differences among masking patterns in patients could facilitate the task of subtyping tinnitus. Here, we studied the variability of hearing thresholds and MMLs among patients with tinnitus to identify tinnitus subgroups. A population of 366 consecutive patients from a specialized tinnitus clinic were included in the analysis. Hearing thresholds and MMLs were determined for octave frequencies from 0.25 to 8kHz, as well as for 3 and 6kHz. Subjects were divided into two groups according to whether their tinnitus was maskable (M, 329 subjects) or non-maskable (NM, 37 subjects). Hearing thresholds and tinnitus loudness did not differ significantly between both groups. The dimensionality of the data was reduced by means of principal component analysis (PCA), and the largest resulting components were used for clustering the data. The cluster analysis resulted in five clusters with differences in tinnitus pitch, lateralization, hearing thresholds and MML, as well as on age and gender. Clusters differed in contours of hearing thresholds and MML, describing patterns of low or high thresholds in combination with low or high MML. The clustering solution presented a low silhouette value (0.45), implying that the clustering is weak and could be artificial. The analysis pointed out the diversity across tinnitus patients. Our results suggest that there might be a continuum of patients' characteristics rather than discrete subgroups.

Comparison of sensorineural hearing loss characteristics in different hemodialysis vascular accesses

Background and Aim: Sensorineural hearing loss (SNHL) is one of the complications in hemodialysis patients. Vascular access (VA) represents a lifeline for these patients affecting their life quality and clinical outcomes. Arterio­venous fistula is the gold standard of VAs with minor complications and better hemodialysis adequacy. There is no study investigating hearing differences in hemodialysis VAs. Hence, this study aimed to compare SNHL characteristics amongst hemodialysis VAs. Methods: This cross-sectional study conducted on 64 patients aged 18−60 years received regular hemodialysis in 2019. Demographic data and comorbid conditions were recorded based on patients’ case records and electronic databases. After a physical examination, otoscopy, tympa­nometry, and conventional audiometry, patients were divided into fistula (n = 26), permanent catheter (n = 36), and temporary catheter (n = 2) groups according to vascular access type. Results: Prevalence rate of SNHL was 63.89%, 50% and 50% in the permanent catheter, fistula and temporary catheter groups, respectively. Most patients had mild sloping-SNHL in the per­manent catheter and fistula groups as against moderate degree in the other group. There was no significant difference in hearing thresholds, deg­ree and audiogram shape among VA groups. No significant relation was found between age, sex, hemodialysis duration and disease duration with hearing loss in all groups (p &gt; 0.05). Conclusion: More patients had SNHL in per­manent catheter group. Vascular access types, longer duration of hemodialysis and disease dur­ation do not seem to be associated with SNHL. However, further investigation is needed to cla­rify the relationship. Keywords: Sensorineural hearing loss; vascular access; chronic renal failure; hemodialysis

Evaluation of hearing acuity in patients with chronic renal failure by pure tone audiometry

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Hearing loss is common in patients with chronic renal failure. It is well known that chronic renal failure (CRF) causes different systemic and otorhinolaryngologic manifestations due to the accumulation of nitrogenous waste products. The aim of the study was to evaluate hearing threshold and the severity of hearing loss at different frequencies in patients of chronic renal failure (CRF), and to analyse the role of duration of disease on hearing threshold in patients of CRF.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Fifty two patients of CRF were included in the study. Pure tone audiometry was done in all cases.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Majority of the patients were in 21 to 40 year age group (mean: out of 52 patients, 38 patients (73.07%) had sensorineural hearing loss and 14 patients (26.93%) had normal hearing. Majority of the patients with hearing loss had mild (44.73%) or moderate (42.11%) sensorineural hearing loss. On comparison of the mean hearing threshold Group II (duration of disease more than five years- 17 patients) showed a statistically significant difference (P&amp;lt;0.05) in mean hearing threshold at 250 Hz.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Hearing loss is present in majority of the patients of CRF. Most of the cases have mild to moderate sensorineural hearing loss. High frequency hearing loss in chronic renal failure is related to the duration of the disease, duration of haemodialysis’ and internal homeostasis, namely hyponatremia.&lt;/p&gt;

Hearing Loss in Patients With Ankylosing Spondylitis: A Systematic Review and Metaanalysis

To determine the prevalence of hearing loss (HL) in patients with ankylosing spondylitis (AS) and to describe frequency-specific hearing threshold changes in this patient population compared to patients without AS. A systematic review querying 4 databases (PubMed, OVID Medline, Scopus, Cochrane) was performed to identify studies evaluating HL in patients with AS. Metaanalysis was performed to identify overall prevalence rate and OR of HL, as well as to compare mean differences in frequency-specific hearing thresholds between patients with and without AS. Our metaanalysis included 14 studies and 1083 patients (598 with AS vs 485 without AS). The pooled prevalence of HL in patients with AS was 42.4% (95% CI 29.2-56.2). Patients with AS had a significantly higher OR of HL than patients without AS (OR 4.65, 95% CI 2.73-7.91). Mean differences in pure-tone hearing thresholds ranged from 0-5 decibels (dB) for frequencies of 0.25-4 kHz, and from 5-15 dB for frequencies of 6-16 kHz. Patients with AS have higher odds of having HL than patients without AS. The AS population also presents with significantly impaired hearing thresholds across all conventional and extended pure-tone frequencies. This may manifest as slight to moderate HL. Results of this systematic review might justify increased attention to audiologic manifestations of patients with AS.

The comparison of changes in hearing thresholds and insertion losses due to occlusion induced by ear impression in sound field assessment

Background and Aim: The methods of deter­mining the amount of sound attenuation by ear mold, earplug or any other foreign body that placed in or out of the ear canal, is divided in subjective and objective. Due to the contradic­tory results in the studies in this field, this study aimed to use more audiometric frequencies con­sidering the strengths and weaknesses of previ­ous studies. Methods: This study was conducted on 30 indi­viduals with normal hearing in the age range of 21-26-year-old. First the impression mold was prepared from both ears. The evaluating real ear unaided response and the real ear occluded res­ponse. In the next step, hearing thresholds were assessed by sound field with a precision of 1 dB, once in both open ear and once in both clo­sed ears. Finally, the insertion loss due to mold placement at each frequency was compared with the amount of behavioral threshold changes at the same frequency. Results: By using paired t-test at frequencies of 400, 500, 800, 1000, 1500, 1600, 2000, 2500, 3000, 4000, 5000, 6000, 6300 and 8000 Hz, the difference in behavioral hearing thresholds with and without molding was greater than the amo­unt of the insertion loss (p &lt; 0.001). Conclusion: The insertion loss due to impre­ssion for behavioral assessment at all of the tes­ted frequencies were more than the attenuation in real ear evaluation (p &lt; 0.001). In this regard, consequently the standard deviation of insertion loss due to impression in behavioral threshold condition was more than real ear measurement. Keywords: Sound field assessment; insertion loss; real ear occluded response; ear impression; probe microphone measurement; real ear measurement

Occupational noise exposure and asymmetric hearing loss: Results from the HUNT population study in Norway.

A large population study with adequate data on confounders is required to determine whether asymmetric hearing loss (AHL) is associated with occupational noise exposure. We performed a cross-sectional population study in Norway (the Health Investigation in Nord-Trøndelag: HUNT) with 24 183 participants, using pure-tone audiometry and questionnaires. AHL was defined as a difference in hearing threshold between the right and left ears of greater than or equal to 15 dB for the pure-tone average of 0.5 to 2 or 3 to 6 kHz. The mean age of the participants was 53 years (range, 19-99); 53% were women. The prevalence of AHL in this general Norwegian population was 6% for the 0.5 to 2 kHz range and 15% for 3 to 6 kHz. In unadjusted regression models, subjects reporting prolonged occupational noise exposure to high-level noise sources (N = 1652) had a higher risk of AHL at 3 to 6 kHz than those reporting no prior exposure (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.75-2.25). After adjustment for age and sex, OR was 1.08; (95% CI, 0.95-1.24). After additional adjustment for head trauma, ear infections, blasting or shooting (all associated with AHL), smoking, and diabetes, OR was 1.00 (95% CI, 0.87-1.16). No association between occupational noise and right-ear hearing threshold advantage (left-right ear difference) was observed after adjustment for confounders. Our study suggests that AHL is relatively common in the general population, especially at the high-frequency range in men and elderly subjects. Our study showed no relation between occupational noise exposure and AHL after confounder adjustment.

Exposure to sodium salicylate disrupts VGLUT3 expression in cochlear inner hair cells and contributes to tinnitus.

To examine whether exposure to sodium salicylate disrupts expression of vesicular glutamate transporter 3 (VGLUT3) and whether the alteration in expression corresponds to increased risk for tinnitus. Rats were treated with saline (control) or sodium salicylate (treated) Rats were examined for tinnitus by monitoring gap-pre-pulse inhibition of the acoustic startle reflex (GPIAS). Auditory brainstem response (ABR) was applied to evaluate hearing function after treatment. Rats were sacrificed after injection to obtain the cochlea, cochlear nucleus (CN), and inferior colliculus (IC) for examination of VGLUT3 expression. No significant differences in hearing thresholds between groups were identified (p>0.05). Tinnitus in sodium salicylate-treated rats was confirmed by GPIAS. VGLUT3 encoded by solute carrier family 17 members 8 (SLC17a8) expression was significantly increased in inner hair cells (IHCs) of the cochlea in treated animals, compared with controls (p<0.01). No significant differences in VGLUT3 expression between groups were found for the cochlear nucleus (CN) or IC (p>0.05). Exposure to sodium salicylate may disrupt SLC17a8 expression in IHCs, leading to alterations that correspond to tinnitus in rats. However, the CN and IC are unaffected by exposure to sodium salicylate, suggesting that enhancement of VGLUT3 expression in IHCs may contribute to the pathogenesis of tinnitus.

Hearing in Schoolchildren After Neonatal Exposure to a High-Dose Gentamicin Regimen.

To assess the association between gentamicin exposure in the neonatal period and hearing in school age. This study included children exposed to a high-dose (6 mg/kg) gentamicin regimen as neonates (2004-2012), invited for follow-up at school age, and a healthy age-matched control group. We assessed hearing with pure tone audiometry including the extended high-frequency (EHF) range. Outcomes were average hearing thresholds in the midfrequencies (0.5-4 kHz) and the EHFs (9-16 kHz). The measures of gentamicin exposure were cumulative dose and highest trough plasma concentration. We used linear regression models to assess the impact of gentamicin exposure, and other peri- and postnatal morbidities, on hearing thresholds. A total of 219 gentamicin-exposed and 33 healthy-control children were included in the audiological analysis. In the gentamicin cohort, 39 (17%) had a birth weight <1500 g. Median cumulative doses and trough plasma concentrations were 30 (interquartile range 24-42) mg/kg and 1.0 (interquartile range 0.7-1.2) mg/L, respectively. Median hearing thresholds for the midfrequencies and the EHFs were 2.5 (0 to 6.3) dB hearing level and -1.7 (-5.0 to 5.0) dB hearing level, both of which were within the normal range. In an adjusted analysis, increasing hearing thresholds were associated with lower birth weight and postnatal middle-ear disease but not level of gentamicin exposure. After adjusting for birth weight, there was no difference in hearing threshold between the gentamicin-exposed cohort and healthy controls. Exposure to a high-dose gentamicin regimen in the neonatal period was not associated with an increase in hearing thresholds in schoolchildren being able to complete audiometry.

Association Between Microvascular Retinal Signs and Age-Related Hearing Loss in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

Given that age-related hearing loss is highly prevalent and treatable, understanding its causes may have implications for disease prevention. To investigate whether microvascular retinal signs are associated with age-related hearing loss attributable to a hypothesized underlying shared pathologic entity involving microvascular disease. The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS) is a community-based prospective cohort study of 15 792 men and women aged 45 to 64 years at baseline. The ARIC-NCS participants returned for a fifth clinic visit in 2011-2013 and a sixth clinic visit in 2016-2017. Participants were recruited from 4 US communities (Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and Minneapolis suburbs, Minnesota). Participants included a subset of the ARIC-NCS cohort with complete covariate data who underwent retinal fundus photography at visit 5 (2011-2013) and completed hearing assessment at visit 6 (2016-2017) (N = 1458). Overall, 453 participants had diabetes; of those, 68 had retinopathy. Of 1005 participants without diabetes, 42 had retinopathy. Microvascular retinal signs included retinopathy, arteriovenous (AV) nicking, and generalized arteriolar narrowing measured using the central retinal arteriolar equivalent (CRAE). Hearing was measured using the better-hearing ear pure-tone average (PTA) of air conduction speech thresholds (0.5, 1, 2, and 4 kHz). Multivariable-adjusted linear and ordered logistic regression was used to estimate the association between microvascular retinal signs and age-related hearing loss to describe the precision of the estimates and provide a plausible range for the true association. After full adjustment among 1458 individuals in the analytic cohort (mean [SD] age, 76.1 [5.0] years [age range, 67-90 years]; 825 women [56.6%]; 285 black [19.5%]), the difference in PTA per dB hearing level in persons with and without retinopathy was 2.21 (95% CI, -0.22 to 4.63), suggesting that retinopathy is associated with poorer hearing, although the width of the 95% CI prevents definitive conclusions about the strength of the observed association. Restricting the analysis to participants without diabetes, the difference in PTA associated with retinopathy was even greater (4.14; 95% CI, 0.10-8.17 dB hearing level), but the large width of the 95% CI prevents definitive conclusions about the association. In analyses quantifying the mean differences in hearing thresholds at individual frequencies by retinopathy status, the estimates trended toward retinopathy being associated, contrary to expectation, with better high-frequency hearing. At 8 kHz, the estimated difference in hearing thresholds in persons with retinopathy vs those without was -4.24 (95% CI, -7.39 to -1.09). In this population-based study, an association between the presence of microvascular retinal signs and hearing loss was observed, suggesting that retinopathy may have the potential to identify risk for hearing loss in persons without diabetes. The precision of these estimates is low; therefore, additional epidemiologic studies are needed to better define the degree of microvascular contributions to age-related hearing loss.

Is Asymmetric Hearing Loss a Risk Factor for Vestibular Dysfunction? Lesson From Big Data Analysis Based on the Korean National Health and Nutrition Survey.

The purpose of this study was to investigate whether asymmetric hearing loss affects vestibular function. Retrospective cross-sectional study. Data from the 2010 Korean National Health and Nutrition Survey for adults aged 40 years or more were used. The modified Romberg test and pure-tone audiometry were performed. Data were analyzed using a complex sample χ test of independence and complex sample logistic regression analysis. Vestibular dysfunction and hearing thresholds. The overall prevalence of vestibular dysfunction was 3.3% (95% confidence interval [CI], 2.5-4.3%). In adults more than 40 years of age, multivariate linear regression analyses showed that the odds ratio (OR) of vestibular dysfunction was 3.067 times higher than the reference for a 30-dB difference in hearing thresholds between both ears (CI, 1.481-6.351; p = 0.007) after adjusting for factors associated with vestibular dysfunction. Among these individuals, the risk of equilibrium disturbance was higher in the presence of low-frequency asymmetric hearing loss (OR, 2.148; CI, 1.216-3.793; p = 0.009); on the other hand, high-frequency asymmetry did not lead to a higher risk. As low-frequency asymmetric hearing thresholds tend to coexist with vestibular dysfunction in adults, those with asymmetric hearing loss should be closely monitored.

Assessment of occupational noise-related hearing impairment among dental health personnel.

ObjectivesThe purpose of the study was to examine hearing thresholds among dental personnel. The secondary aim was to evaluate sound levels among dental equipment that dental personnel are exposed to.MethodsTwo hundred forty‐four dentists, dental technicians, dental assistants, and dental students participated. Sixty‐two participated as a control group. Audiological thresholds for the test groups were compared to the control group. All participants were from Jordan University Hospital. Participants completed a questionnaire in addition to their audiometric testing. Otoscopy, tympanometry, and pure tone audiometry were included in their assessment. Three‐factor ANOVA and t tests were utilized to assess the statistical differences of hearing thresholds among the groups and between the two ears. Pearson correlation test was used to assess the effect of age, experience, and duration of exposure on the degree of hearing loss in the test groups for both ears.ResultsThe authors reported statistically significant differences among hearing thresholds between the control group and others. Left hearing thresholds were noted to be significantly poorer in the left versus right ear at 1000, 2000, 4000, and 8000 Hz in dental assistants. The authors also reported a significant relationship between the degree of hearing impairment among dental assistants and the daily duration of exposure to dental occupational noise, followed by age.ConclusionHearing impairment was higher among dental professionals than the control group and especially among dental assistants and technicians. The authors recommended screening guidelines and adapting hearing protection methods for dental professionals and particularly for dental assistants and technicians.

Behavioral Hearing Thresholds and Distortion Product Otoacoustic Emissions in Cannabis Smokers.

Purpose Cannabis is a widely used drug both medically and recreationally. The aim of this study was to determine if cannabis smoking is associated with changes in auditory function, as measured by behavioral hearing thresholds and/or distortion product otoacoustic emissions (DPOAEs). Method We investigated hearing thresholds and 2f1-f2 DPOAEs in 20 cannabis smokers and 20 nonsmokers between 18 and 28 years old. Behavioral thresholds were obtained from 0.25 to 16 kHz. DPOAEs were measured using discrete tones between f2 of 0.5 and 19.03 kHz using an f2/f1 ratio of 1.22 and L1/L2 = 65/55 dB SPL. Thresholds and DPOAE amplitudes were compared between groups using linear mixed-effects models with sex and frequency as predictors. Results Behavioral thresholds in smokers did not differ significantly between smokers and nonsmokers (all ps > .05). Although not significant, long-term smokers exhibited poorer thresholds than short-term smokers and nonsmokers. Smokers generally exhibited lower DPOAE amplitudes than nonsmokers, although the differences were not significant. Male smokers had significantly poorer DPOAE amplitudes than male nonsmokers in the low frequencies (f2 ≤ 2 kHz; p = .0245). Conclusion Results indicate that smoking cannabis may negatively alter the function of outer hair cells in young men. This subtle cochleopathology is evident in the absence of measurable differences in behavioral hearing thresholds between cannabis smokers and nonsmokers.

Hearing loss among children with sickle cell anaemia in Uganda

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; A case control was carried out to study the prevalence, the pattern and associated factors of hearing loss among Ugandan children with sickle cell anaemia.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; One hundred and thirty-two children known sickle cell and one hundred thirty aged matched non-SCA controls were recruited after medical ethics committee approval and informed consent. Two obtain information on socio-demographic characteristics, history, and examination of the participants, a structured questionnaire was administered. Pure tone audiometry (PTA) was used to assess the hearing in a sound-treated room. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Twenty-two of the children had hearing impairment compared to 6 controls. Prevalence of hearing loss found among children with SCA was 17% but in the control group the prevalence found was 5%. Sensorineural hearing loss (SNHL) affected 39%, conductive (CHL) 25% and mixed (MHL) 14% among cases compared to CHL 7%, SNHL 7% and MHL 7% among the controls. The hearing loss varied from mild to moderate (95%). All sickle cell children had high-frequency hearing loss. There was a statistically significant association of hearing loss and neurologic motor deficit.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Sickle patients are at risk of developing hearing loss as the study demonstrated a difference in hearing threshold in children living with sickle cell anaemia and the controls. High frequencies were more affected. The neurologic motor deficit was highly associated with hearing loss among patients with SCA compared to controls.&lt;/p&gt;

Working Memory and Extended High-Frequency Hearing in Adults: Diagnostic Predictors of Speech-in-Noise Perception.

The purpose of this study was to identify the main factors that differentiate listeners with clinically normal or "near-normal" hearing with regard to their speech-in-noise perception and to develop a regression model to predict speech-in-noise difficulties in this population. We also aimed to assess the potential effectiveness of the formula produced by the regression model as a "diagnostic criterion" for clinical use. Data from a large-scale behavioral study investigating the relationship between noise exposure and auditory processing in 122 adults (30 to 57 years) was re-examined. For each participant, a composite speech-in-noise score (CSS) was calculated based on scores from three speech-in-noise measures, (a) the Speech, Spatial and Qualities of Hearing scale (average of speech items); (b) the Listening in Spatialized Noise Sentences test (high-cue condition); and (c) the National Acoustic Laboratories Dynamic Conversations Test. Two subgroups were created based on the CSS, each comprising 30 participants: those with the lowest scores and those with the highest scores. These two groups were compared for differences in hearing thresholds, temporal perception, noise exposure, attention, and working memory. They differed significantly on age, low-, high-, and extended high-frequency (EHF) hearing level, sensitivity to temporal fine structure and amplitude modulation, linguistic closure skills, attention, and working memory. A multiple linear regression model was fit with these nine variables as predictors to determine their relative effect on the CSS. The two significant predictors, EHF hearing and working memory, from this regression were then used to fit a second smaller regression model. The resulting regression formula was assessed for its usefulness as a "diagnostic criterion" for predicting speech-in-noise difficulties using Monte Carlo cross-validation (root mean square error and area under the receiver operating characteristics curve methods) in the complete data set. EHF hearing thresholds (p = 0.01) and working memory scores (p < 0.001) were significant predictors of the CSS and the regression model accounted for 41% of the total variance [R = 0.41, F(9,112) = 7.57, p < 0.001]. The overall accuracy of the diagnostic criterion for predicting the CSS and for identifying "low" CSS performance, using these two factors, was reasonable (area under the receiver operating characteristics curve = 0.76; root mean square error = 0.60). These findings suggest that both peripheral (auditory) and central (cognitive) factors contribute to the speech-in-noise difficulties reported by normal hearing adults in their mid-adult years. The demonstrated utility of the diagnostic criterion proposed here suggests that audiologists should include assessment of EHF hearing and working memory as part of routine clinical practice with this population. The "diagnostic criterion" we developed based on these two factors could form the basis of future clinical tests and rehabilitation tools and be used in evidence-based counseling for normal hearers who present with unexplained communication difficulties in noise.

Prevalence of Noise-Induced Hearing Loss Among Tanzanian Iron and Steel Workers: A Cross-Sectional Study.

Iron and steel factory workers in Tanzania are likely to develop noise-induced hearing loss (NIHL) due to exposure to high sound levels. Studies on hearing status in this population are lacking. The aims of this study were to determine prevalence of NIHL among iron and steel workers and compare hearing thresholds at different frequencies with a control group. We conducted a cross-sectional study among 221 iron and steel workers exposed to average noise level of 92 dB(A), compared with 107 primary school teachers recruited as controls and exposed to average noise level of 79.7 dB(A). We used a questionnaire-based interview to collect information on socio demographic characteristics and other confounding variables. Hearing loss was defined as hearing threshold levels ≥25 dB hearing loss in either ear at 3000, 4000 or 6000 Hz. The prevalence of hearing loss was significantly higher among the exposed group than among the controls, i.e. 48% and 31%, respectively. There were significant differences in hearing thresholds between the exposed and control groups at 3000, 4000, 6000, and 8000 Hz. Hearing loss was more frequent among workers exposed to higher noise levels than among the controls suggesting that iron and steel workers run a higher risk of developing hearing loss.