Hearing Threshold Measurements Research Articles

Electroacoustic evaluation of the bone conduction transducer B250 for vestibular and hearing diagnostics in comparison with Radioear B71 and B81

Objective The objective is to evaluate the electroacoustic performance of the B250 transducer and to compare it with the two most widely used audiometric transducers B71 and B81. Design The electroacoustic performance was evaluated in terms of sensitivity level, distortion, maximum hearing level and electrical impedance. Study sample Six B250 prototype transducers were evaluated and compared with published data of B71 and B81 together with complementary measurements of maximum hearing level at 125 Hz and phase of electrical impedance. Differences in reference equivalent threshold vibratory force levels were estimated by comparing hearing threshold measurements of 60 healthy ears using B81 and B250. Results B250 has approximately 27 dB higher sensitivity levels than both B71 and B81 at 250 Hz and can generate higher maximum hearing level at low frequencies: 11.8 to 35.8 dB (125–1000 Hz) higher than B71, and 1.4 to 18.6 dB (125–750 Hz) higher than B81. The maximum average difference in reference threshold force levels was 13.5 ± 8.7 dB higher for B250 at 250 Hz compared to B81. Conclusions B250 can produce higher output force with less distortion than B71 and B81, especially at 125 and 250 Hz, which could possibly improve low frequency investigations of the audio-vestibular system.

Hypothesis Tests for Continuous Audiometric Threshold Data.

Hypothesis tests for hearing threshold data may be challenging due to the special structure of the response variable, which consists of the measurements from the participant's two ears at multiple frequencies. The commonly-used methods may have inflated type I error rates for the global test that examines whether exposure-hearing threshold associations exist in at least one of the frequencies. We propose using both-ear methods, including all frequencies in the same model for hypothesis testing. We compared the both-ear method to commonly used single-ear methods, such as the worse-ear, better-ear, left/right-ear, average-ear methods, and both-ear methods that evaluate individual audiometric frequencies in separate models, through both theoretical consideration and a simulation study. Differences between the methods were illustrated using hypothesis tests for the associations between the Dietary Approaches to Stop Hypertension adherence score and 3-year change in hearing thresholds among participants in the Conservation of Hearing Study. We found that (1) in the absence of ear-level confounders, the better-ear, worse-ear and left/right-ear methods have less power for frequency-specific tests and for the global test; (2) in the presence of ear-level confounders, the better-ear and worse-ear methods are invalid, and the left/right-ear and average-ear methods have less power, with the power loss in the left/right-ear much greater than the average-ear method, for frequency-specific tests and for the global test; and (3) the both-ear method with separate analyses for individual frequencies is invalid for the global test. For hypothesis testing to evaluate whether there are significant associations between an exposure of interest and audiometric hearing threshold measurements, the both-ear method that includes all frequencies in the same model is the recommended analytic approach.

Biosafety and potency of high-molecular-weight hyaluronic acid with intratympanic dexamethasone delivery for acute hearing loss.

Objective: This study evaluated the potential of high-molecular-weight hyaluronic acid (HHA) as an intratympanic (IT) drug delivery vehicle for dexamethasone (D) in treating acute hearing loss. We compared the efficacy, safety, and residence time of HHA to the standard-of-care IT drug delivery method. Methods: Endoscopic examinations were used to track tympanic membrane (TM) healing post-IT injection. Micro-computed tomography (CT) was used to gauge drug/vehicle persistence in the bulla air space. Histological analyses covered the middle ear, TM, and hair cell counts. Auditory brainstem responses (ABR) were used to measure hearing thresholds, while high-performance liquid chromatography (HPLC) was employed to quantify cochlear perilymph dexamethasone concentrations. Results: The HHA + D group had a notably prolonged drug/vehicle residence time in the bulla (41 ± 27days) compared to the saline + D group (1.1 ± 0.3days). Complete TM healing occurred without adverse effects. Histology revealed no significant intergroup differences or adverse outcomes. Hearing recovery trends favored the HHA + D group, with 85.0% of ears showing clinically meaningful improvement. D concentrations in cochlear perilymph were roughly double in the HHA group. Conclusion: HHA is a promising vehicle for IT drug delivery in treating acute hearing loss. It ensures extended residence time, augmented drug concentrations in targeted tissues, and safety. These results highlight the potential for HHA + D to excel beyond existing standard-of-care treatments for acute hearing loss.

Effects of noise on the hearing of intensive care unit nurses

This study aims to investigate the hearing problems experienced by nurses working in the intensive care units (ICUs) and gastroenterology departments of a hospital in China. A total of 93 participants who are currently employed in these settings were recruited for the study. The research methodology involved several components. Firstly, the pure tone audiometry (PTA) hearing threshold measurements were conducted in a closed audiometry room. The air conduction hearing and bone conduction hearing thresholds were recorded using calibrated equipment. Secondly, the participants underwent the Digits In Noise (DIN) test to assess their speech reception threshold in a noisy environment. They were instructed to wear headphones and adjust the volume to be a comfortable level while Chinese digit triplets were presented with a background masking noise. Thirdly, a questionnaire with previously validated and subjective components was also administered after the PTA and DIN tests. The survey aimed to assess self-reported auditory dysesthesia, including symptoms such as tinnitus, aural fullness, and otalgia. It was observed that ICU nurses exhibited more hearing loss at high frequencies above 4 kHz compared to non-ICU nurses. Additionally, nurses who worked more hours per week demonstrated worse hearing thresholds. Furthermore, ICU nurses reported more severe self-reported hearing problems compared with non-ICU nurses.

Association between occupational noise-induced hearing loss and genotoxicity among textile factory workers

Background/aimHearing loss caused by exposure to noise is still among the most prevalent health risks for industrial workers. This study aims to evaluate the relationship between Shebien El-kom textile factory workers’ occupational noise exposure, genotoxicity, and noise-induced hearing loss.MethodsThis cross-sectional case–control study was performed in a textile industry in Shebin Elkom, Egypt. The participants of this work were 36 exposed male workers from the spinning section of the textile factory and 36 subjects as the control male group from administrative staff in the same factory, in the age range of 25–45 years. A pure-tone audiometer and portable sound level meter were utilized for the measurement of hearing threshold and noise level, respectively. Genotoxicity was assessed using the Comet assay technique.ResultsThere was no significant difference between both groups regarding age and the mean duration of work was 18.94 ± 4.88 for exposed workers. The average level of noise was 95–105 dB (A). The exposed workers’ mean hearing thresholds for the left and right ears at frequencies between 2000 and 8000 Hz were substantially greater than those of the control group (P < 0.05). In the exposed workers, there was not a marked variation between the hearing thresholds of the left and right ears (p > 0.05). The exposed workers’ percentage of DNA damage was substantially greater than that of the control group (p < 0.001). Among exposed workers, a positive correlation between DNA damage, the degree of hearing loss, and the duration of time exposed to noise was demonstrated.ConclusionThe majority of exposed workers suffered from occupational noise-induced hearing loss. A positive correlation was found between the percentage of DNA damage, duration of exposure to noise, and hearing threshold in exposed workers.

Hyperacusis Assessment Questionnaire-A New Tool Assessing Hyperacusis in Subjects with Tinnitus.

Hyperacusis, a kind of decreased sound tolerance, is difficult to measure objectively. It often co-occurs with tinnitus. There is a need for valid and reliable patient-reported outcome measures to capture this subjective phenomenon. The aim of the study was to create a questionnaire capturing hyperacusis in terms of loudness, fear, and pain and to evaluate its psychometric properties. The study sample consisted of 106 adult patients with hyperacusis and tinnitus with a mean age of 45.2 years. A medical interview, an audiological examination, and several questionnaires (the Tinnitus Handicap Inventory, the Hyperacusis Questionnaire, the State-Trait Anxiety Inventory, and Visual Analog Scales) were applied. The final 14-item Hyperacusis Assessment Questionnaire showed an appropriate three-factor structure with 70.5% of the variance explained. Convergent and divergent validity were confirmed by correlations with other measures of hyperacusis, anxiety, tinnitus severity, misophonia, and hearing thresholds. The internal consistency assessed with Cronbach's alpha was excellent (α = 0.91), as was reproducibility (intraclass correlation, ICC = 0.96). The new Hyperacusis Assessment Questionnaire is a psychometrically sound and brief tool assessing the severity of hyperacusis in terms of loudness, fear, and pain. It can be used in clinical practice and scientific research for patients with hyperacusis and tinnitus.

Mobile audiometry for hearing threshold assessment: A systematic review and meta-analysis.

Technological advancements in mobile audiometry (MA) have enabled hearing assessment using tablets and smartphones. This systematic review (PROSPERO ID: CRD42021274761) aimed to identify MA options available to health providers, assess their accuracy in measuring hearing thresholds, and explore factors that might influence their accuracy. A systematic search of online databases including PubMed, Embase, Cochrane, Evidence Search and Dynamed was conducted on 13th December 2021, and repeated on 30th October 2022, using appropriate Medical Subject Headings (MeSH) terms. Eligible studies reported the use of MA to determine hearing thresholds and compared results to conventional pure-tone audiometry (CA). Studies investigating MA for hearing screening (i.e. reporting just pass/fail) were ineligible for inclusion. Two authors independently reviewed studies, extracted data, and assessed methodological quality and risk of bias using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Adults and children, with and without diagnosis of hearing impairment. A meta-analysis was performed to obtain the mean difference between thresholds measured using MA and CA in dB HL. Searches returned 858 articles. After systematic review, 17 articles including 1032 participants were analysed. The most used software application was ShoeboxTM (6/17) followed by Hearing TestTM (3/17), then HearTestTM (2/17). Tablet computers were used in ten studies, smartphones in six, and a computer in one. The mean difference between MA and CA thresholds was 1.36 dB (95% CI, 0.07-2.66, p = 0.04). Significant differences between mobile audiometry (MA) and conventional audiometry (CA) thresholds were observed in thresholds measured at 500Hz, in children, when MA was conducted in a sound booth, and when MA was self-administered. However, these differences did not exceed the clinically significant threshold of 10 decibels (dB). Included studies exhibited high levels of heterogeneity, high risk of bias and low concerns about applicability. MA compares favourably to CA in measuring hearing thresholds and has role in providing access to hearing assessment in situations where CA is not available or feasible. Future studies should prioritize the integration of pure-tone threshold assessment with additional tests, such as Speech Recognition and Digits-in-Noise, for a more rounded evaluation of hearing ability, assesses acceptability and feasibility, and the cost-effectiveness of MA in non-specialist settings.

Vestibular function in children with vestibulocochlear nerve aplasia/hypoplasia

Background Infants and young children with vestibulocochlear nerve (VCN) hypoplasia/aplasia present with severe hearing loss and are candidates for cochlear implantation (CI). It is unknown whether vestibular function is related to CI outcome and if vestibular tests can guide the operation decision. Aims/Objectives Our aim was to describe the vestibular function in patients with VCN hypoplasia/aplasia before a possible CI. Materials and Methods Forty-two ears in 23 patients were tested between 2019 and 2022 with bone-conducted cervical vestibular evoked myogenic potentials (BCcVEMP), video head impulse test (vHIT) and miniice-water caloric test (mIWC). Results All ears could be tested with at least one vestibular test and 83% could be tested with more than one method. Twenty-nine ears (61%) showed normal function with at least one method. The presence of a normal response to any test doubled the likelihood of a measured hearing threshold after CI, the best predictors being the BCcVEMP and vHIT (p < 0.05). Conclusion Canal function may represent a predictor of auditive pathway integrity with a possible favourable audiological outcome after CI operation Significance Our results demonstrate high vestibular response rates suggesting a functioning pathway despite the radiological diagnosis.

Unilateral crosstalk cancellation via bone conduction: Methods and evaluation

Bone conduction hearing aids (BCHAs) offer an alternative solution for individuals with outer or middle ear issues who cannot benefit from traditional air conduction hearing aids. However, the phenomenon of “crosstalk,” where sound intended for one ear is mistakenly transmitted to the other ear through bone conduction, presents a challenge. This unintended transmission may limit the benefits of binaural hearing that can be achieved using two BCHAs, such as accurately detecting a sound source's direction. In this article, we present a method to suppress “crosstalk” within the human head using an adaptive algorithm to control two audiometric bone transducers.•Our method involves positioning an error sensor at a location considered close to the cochlea, such as the ear canal or the mastoid, and utilizing an adaptive algorithm to estimate the crosstalk compensation filter. This filter generates an anti-signal, which is then transmitted to one of the two transducers, effectively cancelling the crosstalk.•To verify whether the crosstalk cancellation reaches the cochlea in the inner ear, we provide a procedure for measuring hearing thresholds with and without crosstalk cancellation. This acts as a subjective measure of the efficacy of our crosstalk cancellation method.By leveraging an adaptive algorithm, this approach provides personalized cancellation and has the potential to enhance the performance of binaural BCHAs.

Testing the reliability and validity of the modified Amsterdam Inventory for Auditory Disability and Handicap in career firefighters in the United States.

Firefighters are routinely exposed to loud noise that put them at risk for hearing loss. A reliable and valid measure to assess firefighters' hearing function is important. This study aims to test the reliability and validity of the modified Amsterdam Inventory for Auditory Disability and Handicap ((m)AIADH) in firefighters. A cross-sectional study was conducted using a convenience sample of 239 career firefighters from six partnered fire departments in Central Texas and Northern California. The internal consistency, convergent and criterion validity, and the ability to discriminate groups by measured hearing, perceived hearing, and a combination of measured and perceived hearing, were examined using the total score and score for each of the five subscales of the (m)AIADH. The study participants were primarily men (93%). Satisfactory internal consistency was revealed for the (m)AIADH with Cronbach's alpha above 0.80 for all five subscales. Criterion analysis presented a moderate correlation between the (m)AIADH and the average of hearing threshold at high frequencies (4, 6, and 8 kHz). For convergent validity, the (m)AIADH was moderately to highly related with perceived hearing. There were statistically significant differences in the total (m)AIADH score and the five subscales for measured hearing thresholds except for "intelligibility in quiet." The (m)AIADH also showed a discriminative ability to distinguish between the group with good perceived hearing and the group with bad perceived hearing. The (m)AIADH is a reliable and valid measure to assess various dimensions of hearing function among firefighters.

Audiological Tests Used in the Evaluation of the Effects of Solvents on the Human Auditory System: A Mixed Methods Review.

This study aimed to scope the literature, identify knowledge gaps, appraise results, and synthesize the evidence on the audiological evaluation of workers exposed to solvents. We searched Medline, PubMed, Embase, CINAHL, and NIOSHTIC-2 up to March 22, 2021. Using Covidence, two authors independently assessed study eligibility, risk of bias, and extracted data. National Institute of Health Quality Assessment Tools was used in the quality evaluation of included studies; the Downs and Black checklist was used to assess the risk of bias. Of 454 located references, 37 were included. Twenty-five tests were studied: two tests to measure hearing thresholds, one test to measure word recognition in quiet, six electroacoustic procedures, four electrophysiological tests, and twelve behavioral tests to assess auditory processing skills. Two studies used the Amsterdam Inventory for Auditory Disability and Handicap. The quality of individual studies was mostly considered moderate, but the overall quality of evidence was considered low. The discrepancies between studies and differences in the methodologies/outcomes prevent recommending a specific test battery to assess the auditory effects of occupational solvents. Decisions on audiological tests for patients with a history of solvent exposures require the integration of the most current research evidence with clinical expertise and stakeholder perspectives.

Occlusion effects by bone-conducted sound to the facial parts assessed by hearing threshold and ear canal sound pressure

Bone conduction (BC) is used in devices such as hearing aids and earphones. Audio devices using BC on the face have been developed; however, limited research has addressed the perception of BC sounds on the face. BC also entails an occlusion effect (OE), wherein the loudness of low-frequency sounds is enhanced when the ear canal is occluded. We evaluated the characteristics of OE by measuring hearing thresholds and ear canal sound pressure (ECSP) during BC stimulation of several facial parts. We compared them with those of conventionally used parts. OE, the difference in hearing thresholds between the open and occluded ears, was equal to or larger than that of conventionally used parts. The difference in ECSP was smaller than that in OE, indicating that BC components transmitted to the middle and inner ears affected OE in these facial parts. The complicated structure of the face may have affected the results.

Forty-plus years of Navy research by the dolphin BLU

The dolphin “BLU” has had an amazing career spanning over 40 years of Navy fleet support and scientific research. Her research career began in the late 1970s with Sam Ridgway, studying lung-collapse and intramuscular nitrogen levels in diving dolphins. For the next several decades, she served with the Navy’s Fleet mine-hunting systems and was deployed to locations all over the world. In 2003, at age 37, BLU returned to research, where her intelligence and unflappable demeaner quickly made her a star. Over the next few years she participated in a number of studies using behavioral and auditory evoked potential techniques to measure hearing thresholds and temporary threshold shift (TTS). TTS data from BLU were instrumental in developing marine mammal noise exposure regulatory guidelines. After having a calf in 2007, she became a working mom by beaching and transporting to the test pool each day, then returning to her calf at the conclusion of the session. BLU would go on to participate in a number of studies involving directional hearing, tactile sensitivity, and biosonar beam patterns. This talk will review BLU’s career with the Navy and highlight her research contributions that have resulted in over 35 peer-reviewed journal articles.

Basic perception and propagation characteristics of bone-conducted sounds presented to facial parts

In conventional bone conduction (BC) devices, a vibrator is typically applied to the mastoid or condyle processes. Recently, however, BC-sound presentations to facial parts such as the nose have also been investigated. As the face is among the most complex structures in the human body, BC sounds presented to facial parts are likely to show different perception and propagation characteristics from those presented to conventional parts. We measured hearing thresholds, ear canal sound pressures in both ears, and head vibrations at both mastoid processes when BC sounds were presented to the facial (nasal, infraorbital region, zygomatic, jaw angle, and chin) and conventional (mastoid and condyle processes and forehead) parts of normal-hearing subjects. The results indicated that the facial parts and mastoid process had similar threshold characteristics. By changing the stimulus parts on the face, the hearing thresholds did not change, whereas the amplitudes of each propagation component changed significantly.

Measure of Hearing Threshold in Borma / Bakery Workers

Measure of Hearing Threshold in Borma / Bakery Workers

An investigation on source identification of very high frequency sounds radiated from home appliances around us.

We investigated the azimuth angle characteristics of head related transfer function (HRTF) at very high frequency region using two kinds of head and torso simulators (HATS). In the measurement of hearing thresholds, there are two ways using a headphone or a loudspeaker. In general, it will be carried out using a loudspeaker because sound pressure calibration and measurement are simple. However, the hearing threshold which measured using a loudspeaker at very high frequency region may contain some errors because sound pressure level (SPL) reaching the ear are seriously affected by a small movement of the head. Also, the SPL near the pinna seriously depends on both shapes of a pinna and a head because excess attenuation by diffraction of VHF sound is very large. To provide assurance for the accuracy measurement of hearing threshold, it is important to make clear the relationship between the SPL and shape of head and/or ear. In this paper, we reported the HRTFs calculated from the SPLs measured at three different positions of left ear - a tragus, an auricle and an eardrum and discussed the influence of head and/or ear of HATS from the azimuth angle characteristics of these HRTFs.

Boothless audiometry: Ambient noise considerations

Ambient noise in the test environment will impact signal detection during hearing threshold measurements due to psychoacoustic masking effects. Technical standards specify the maximum permissible ambient noise levels (MPANLs) for use during audiometric testing. MPANLs are dependent on several factors, including transducer characteristics (supra-aural, circumaural, type of ear cushions or earphone enclosures, and insert earphones), the nature of the hearing test being performed (air conduction vs bone conduction and threshold test vs screen at a suprathreshold level), and measurement instrumentation. The nature of the ambient noise (spectrum and constant vs variable) at the test site must be determined and continually accounted for during the boothless hearing test procedure. Ambient noise monitoring procedures are reviewed and examples of ambient noise characteristics in real-world settings, where hearing testing might be performed outside of a sound-treated environment, are provided. Practical considerations are presented, including examples of available tools for ambient noise monitoring, selection of test locations, and transducer attenuation. These are discussed in the context of calculating MPANLs and how best to ensure that ambient noise levels are not negatively impacting the validity of hearing thresholds.

Evaluation omn three-forced choice audiometry for hearing threshold measurement

Common audiometry used in hospitals uses the 2AFC (Two Force Choice) method, which has a large and predictable bias. In this research, the three-force choice (3AFC) method is proposed for a smaller bias to measure hearing threshold. A hearing test was conducted on 50 participants. Three kinds of audiometric tests are used, including conventional, Pychoacoustic, and portable audiometry. A validation test was carried out by comparing the results of Pychoacoustic and portable audiometric tests using the 3AFC method with the golden standard (conventional audiometry). Pychoacoustic audiometry is unable to display the hearing threshold value in accordance with that shown by golden standard audiometry (conventional audiometry), where the mean value is 18.0–43.0, and standard deviation is 7–12 . However, the portable audiometry test is able to display a threshold value that is close to the golden standard audiometric results, with a mean value of 11—28, and standard deviation value of 3—6 . Based on the statistical calculation of the Wilcoxon test and Bonferroni's correction, it can be concluded that data collection using Pychoacoustic outdoors and Portable in the relevant room has performance that is parallel to the golden standard test (sig value &amp;gt;0.05).

Perception and Propagation Characteristics of Bone-Conducted Stimuli Presented to the Human Facial Cranium.

Since bone conduction (BC) has the advantage that it does not cover the ear canal and can be easily heard even when earplugs are worn, it has been applied to various communication devices. Conventional BC is mainly applied to the mastoid process of the temporal bone (the osseous bulge behind the ear), however, some of recent BC devices, such as smart glasses, present stimuli to faces. The face has very complex structures in the human body; therefore, it is highly likely that the hearing and propagation characteristics of sound will change depending on the part to which sound is presented. However, the characteristics of BC presented to the face has not yet been studied in detail. In this study, we measured hearing threshold and ear canal sound pressure (ECSP) when BC stimuli were presented to various parts of the facial cranium (nasal, infraorbital region, zygomatic, jaw angle, and chin), and compared them with conventional placements of BC stimulus (the mastoid process, condyle process, and forehead). The facial parts such as the infraorbital region, zygomatic, and jaw angle had similar hearing thresholds and ECSPs to those of the mastoid process. The results suggested that these facial parts can be used as stimulus placements of BC devices.

Comparison of Auditory Steady-State Responses With Conventional Audiometry in Older Adults.

Behavioral measures, such as pure-tone audiometry (PTA), are commonly used to determine hearing thresholds, however, PTA does not always provide reliable hearing information in difficult to test individuals. Therefore, objective measures of hearing sensitivity that require little-to-no active participation from an individual are needed to facilitate the detection and treatment of hearing loss in difficult to test people. Investigation of the reliability of the auditory steady-state response (ASSR) for measuring hearing thresholds in older adults is limited. This study aimed to investigate if ASSR can be a reliable, objective measure of frequency specific hearing thresholds in older adults. Hearing thresholds were tested at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz in 50 participants aged between 60 and 85 years old, using automated PTA and ASSR. Hearing thresholds obtained from PTA and ASSR were found to be significantly correlated (p < .001) in a cohort consisting of participants with normal hearing or mild hearing loss. ASSR thresholds were significantly higher as compared to PTA thresholds, but for the majority of cases the difference remained within the clinically acceptable range (15 dB). This study provides some evidence to suggest that ASSR can be a valuable tool for estimating objective frequency-specific hearing thresholds in older adults and indicate that ASSR could be useful in creating hearing treatment plans for older adults who are unable to complete behavioral PTA. Further research on older adults is required to improve the methodological features of ASSR to increase consistency and reliability, as well as minimize some of the limitations associated with this technique.