Bone Vibrator Research Articles

Evaluation of the microbial contamination of the audiological diagnostic equipment and, their current disinfection techniques

BackgroundThe study aims to investigate the microbial contamination of commonly used audiological diagnostic equipment and to evaluate the effectiveness of existing disinfection methods in audiological clinics. MethodsHospitals with fully equipped audiology clinics in Istanbul were included in the study. Various audiological diagnostic devices, such as Pure Tone Audiometer, Tympanometer, and Auditory Brainstem Response (ABR), were examined. The study also investigated the disinfection practices in hospitals. A total of 60 swab samples were collected from the stimulus button on the audiometer, patient response switch, supraaural headphone cushion, bone conduction headphone (bone vibrator), and disinfected probe tips used in the Tympanometer and ABR. ResultsBacterial growth was observed on 40% of the analyzed plates, with 11.66% showing two different types of bacterial growth. Staphylococcaceae family were the most common bacteria identified. Other bacteria included Pseudomonas putida, Panteoa spp, Micrococcus luteus, Corynebacterium spp, and Bacillus spp. The highest bacterial growth occurred on the supraaural headphone cushion and bone vibrator. ConclusionsThe study highlights the presence of various bacteria on audiological diagnostic equipment, emphasizing Staphylococcus species as predominant. Current disinfection practices, particularly for supraural headphones and bone vibrators, were found to be inadequate, potentially posing risks for infections. The study suggests the need for disinfection protocols, particularly for frequently touched devices, to ensure patient safety in clinics.

Directional sensitivity of bone conduction stimulation on the otic capsule in a finite element model of the human temporal bone

Sound transmission to the human inner ear by bone conduction pathway with an implant attached to the otic capsule is a specific case where the cochlear response depends on the direction of the stimulating force. A finite element model of the temporal bone with the inner ear, no middle and outer ear structures, and an immobilized stapes footplate was used to assess the directional sensitivity of the cochlea. A concentrated mass represented the bone conduction implant. The harmonic analysis included seventeen frequencies within the hearing range and a full range of excitation directions. Two assessment criteria included: (1) bone vibrations of the round window edge in the direction perpendicular to its surface and (2) the fluid volume displacement of the round window membrane. The direction of maximum bone vibration at the round window edge was perpendicular to the round window. The maximum fluid volume displacement direction was nearly perpendicular to the modiolus axis, almost tangent to the stapes footplate, and inclined slightly to the round window. The direction perpendicular to the stapes footplate resulted in small cochlear responses for both criteria. A key factor responsible for directional sensitivity was the small distance of the excitation point from the cochlea.

Bone-Anchored Hearing Aid Effects on Vestibular Function: A Preliminary Report.

Cochlear receptors are sensitive to vibratory stimuli. Based on this sensibility, bone-anchored hearing aids have been introduced to correct unilateral or bilateral conductive or mixed hearing loss and unilateral deafness. The vestibular system is also sensitive to the vibratory stimulus and this type of response is used in clinics to test its functionality. Being aware of this double separated sensibility, we wondered whether bone vibration, which activates the acoustic receptors of patients with bone conduction aids, can also influence the functionality of the vestibular system. To this end, we recruited 12 patients with a bone-anchored hearing aid and evaluated their vestibular function with and without an activated vibratory acoustic device. Our results show that the vibratory stimulus delivered by the bone conduction aid also reaches and stimulates the vestibular receptors; this stimulation is evidenced by the appearance or modification of some nystagmus findings during bedside vestibular testing. Despite this, none of these patients complained of dizziness or vertigo during prosthesis use. Nystagmus that appeared or changed during acoustic vibratory stimulation through the prosthesis was almost all predominantly horizontal, unidirectional with respect to gaze or body position, inhibited by fixation, and most often consistent with vestibular function tests indicating peripheral vestibular damage. The findings of sound-evoked nystagmus seem to indicate peripheral rather than central vestibular activation. The occurrence of some predominantly horizontal and high-frequency induced nystagmus seems to attribute the response mainly to the utricle and lateral semicircular canal.

Soft Tissue Conduction Activates the Auditory Pathway in the Brain.

Soft tissue conduction is a mode of hearing which differs from air and bone conduction since the soft tissues of the body convey the audio-frequency vibrations to the ear. It is elicited by inducing soft tissue vibrations with an external vibrator applied to sites on the body or by intrinsic vibrations resulting from vocalization or the heartbeat. However, the same external vibrator applied to the skin sites also excites cutaneous mechanoreceptors, and attempts have been made to assist patients with hearing loss by audio-tactile substitution. The present study was conducted to assess the contribution of the auditory nerve and brainstem pathways to soft tissue conduction hearing. The study involved 20 normal hearing students, equipped with ear plugs to reduce the possibility of their response to air-conducted sounds produced by the external vibrator. Pure tone audiograms and speech reception (recognition) thresholds were determined in response to the delivery of the stimuli by a clinical bone vibrator applied to the cheek, neck and shoulder. Pure tone and speech recognition thresholds were obtained; the participants were able to repeat the words they heard by soft tissue conduction, confirming that the auditory pathways in the brain had been stimulated, with minimal involvement of the somatosensory pathways.

Finite element modelling tibia bone vibration – the influence of shape, twist, and end scale

The percussion response of long bone has the potential to be used as a measure of bone strength for Osteoporosis detection. Modelling the vibration response requires describing the shape of the long bone which can have several features. An overly simplistic model of the shape does not give enough insight into their influence on the vibration response. This paper identifies the key features of the shape of a tibia and femur bone (cross-sectional shape, twist, and scale of the ends) and investigates their individual effects on the eigenfrequencies using finite element modelling. A femur and tibia model are dissected at the thicker ends and length adjusted to isolate the influence of the proximal and distal ends on the eigenfrequencies. Selected cross-sectional shapes are investigated to simplify the modelling and compared to real bone cross-sections and results. The twist is added across the longitudinal axis of the model producing an inline twist to the cross-section and resulting in a 1.5–2.5% decrease in frequencies per 20° of twist. The scale of the cross-sections at the ends of the model are increased along a set length of the bone to emulate the larger proximal and distal end of the long bones. The results show that any model for the vibro-acoustic response of long bones needs to include asymmetry in the cross-section as well as the scaling of the ends.

Clinical profiling of pediatric microtia patients: A cross-sectional analysis at a leading pediatric hospital in Ecuador (2015-2022).

Microtia is a frequent congenital deformity of the pinna, often with hearing loss. This study reviews the clinical profiles of microtia pediatric patients treated at a referral hospital in Quito, Ecuador, from 2015 to 2022. A cross-sectional descriptive study was carried out based on the analysis of medical records of pediatric patients with microtia treated between January 2015 and December 2022 at the Hospital Pediátrico Baca Ortiz in Quito, Ecuador. Descriptive statistics were used, and the Chi-square test assessed associations between categorical variables. Of the 235 patients evaluated, 59.6% were male, 83.4% lived at high altitudes (2500-3500 m), and 19.1% had a family history of microtia. Grade III microtia was diagnosed in 63.8%, predominantly on the right side. Nearly all (99.1%) had hearing loss. Other anatomical alterations were observed in 27.7%, primarily the preauricular appendage. Bone vibrator implantation was a common treatment for 24.3%. Altitude did not show a significant correlation with microtia characteristics. Most patients had grade III microtia with associated hearing loss. Despite the high prevalence at elevated altitudes, no significant altitude-disease correlation was found. The study highlights the need for further research on microtia in regions like Ecuador.

In Vivo Measurement of Ear Ossicle and Bony Wall Vibration by Sound Stimulation of Cartilage Conduction.

The cartilage-conduction pathway was recently proposed as a third auditory pathway; however, middle-ear vibrations have not yet been investigated in vivo. We aimed to measure the ossicles and bone vibration upon cartilage-conduction stimulation with a non-contact laser Doppler vibrometer. We recruited adult patients with normal ear structures who underwent cochlear implant surgery at our hospital between April 2020 and December 2022. For sound input, a cartilage-conduction transducer, custom-made by RION Corporation (Tokyo, Japan), was fixed to the surface of the tragus and connected to an audiometer to regulate the output. A posterior tympanotomy was performed and a laser beam was directed through the cavity to measure the vibration of the ossicles, cochlear promontory, and posterior wall of the external auditory canal. Five participants (three men, mean age: 56.4 years) were included. The mean hearing loss on the operative side was 96.3 dB HL in one patient, and that of the other patients was off-scale. The vibrations were measured at a sound input of 1 kHz and 60 dB. We observed vibrations of all three structures, demonstrating the existence of cartilage-conduction pathways in vivo. These results may help uncover the mechanisms of the cartilage-conduction pathway in the future.

Vibration Thresholds Using Conventional Audiometry are Clinically Useful Indicators of Postural Instability in Older Adults.

Falls are a major health concern with potentially dramatic consequences for people over 65 years of age. One crucial determinant in the risk of falls in older adults is postural control, a complex process that requires the contribution of different sensory modalities, namely visual, vestibular, auditory, and somatosensory. While there are well-established methods to screen for age-related vision, hearing, tactile, and vestibular impairments, there are very few widely available methods to screen for somatosensory function, but studies indicate that ankle audiometry (vibration thresholds) using a common B-71 bone vibrator can serve that purpose. To date, unfortunately, this technique has received little attention as a tool to measure postural instability in older adults. The objective of the present study was to examine postural control in older adults with and without degradation of the somatosensory functions, as determined with ankle audiometry. This was standard group comparison. In total, 36 healthy elderly aged between 65 and 80 years old were divided into two groups (low vibration threshold [n = 18] and high vibration threshold [n = 18]). Standard audiometry, video head impulse test, vibration thresholds (big toe, ankle, and tibia), and static postural control task using a force platform were performed. Greater postural instability in participants with higher (worse) vibration thresholds as compared with participants with lower (better) vibration thresholds was observed even though both groups were comparable on hearing threshold and vestibular function. The results indicate that performing a simple vibration threshold evaluation, using a clinically available B-71 with a cut-off value of 42 dB hearing loss, could be an effective, fast, and easy-to-use procedure for detecting people at risk of falls.

The influence of midsole horizontal and vertical deformation on soft tissue vibrations and bone acceleration during running

ABSTRACT Increased midsole deformation can limit exposure to high impact and vibration magnitudes while running. The aim of this study was to evaluate the effect of shoes eliciting different midsole deformation on ground reaction forces, heel impact, soft tissue vibrations and bone vibrations. Forty-eight runners performed a 5-min running task on an instrumented treadmill at a self-selected pace with four different shoes. Midsole horizontal and vertical deformations were quantified with relative displacement of seven reflective markers placed on the midsole of the shoe and tracked by eight optoelectronic cameras. Heel impacts, soft tissue and bone vibrations of lower leg muscle groups, sacrum and head were quantified with tri-axial accelerometers. Continuous wavelet transform was used to assess magnitude and frequency of the acceleration data. Linear mixed models and non-parametric one-dimensional regressions between the accelerometer data and shoe deformation were performed. Greater horizontal and vertical deformations decreased the magnitude (up to 4.6% per mm) and frequency (up to 0.6 Hz per mm) of soft tissue vibrations and bone accelerations. Accelerations of the heel, tibia, gastrocnemius medialis and vastus lateralis were more influenced than the sacrum and head. Increasing midsole deformation could therefore mitigate the risk of injury, while increasing running comfort and smoothness.

Contralateral bone conducted sound wave propagation on the skull bones in fresh frozen cadaver

The study aimed to investigate the efficient pathway for BC sound transmission by measuring vibrations on the opposite side of the skull bone, referred to as the mastoid position. The realistic contralateral transmission pathway of bone conduction (BC) vibrations is investigated through each osseous structure in the midlines of the fresh-frozen whole head. BC stimulation is applied to the mastoid using a bone vibrator, and acceleration responses are observed on the contralateral mastoid bone and seven midline points of skull bones using triaxial accelerometers. The study finds that the range showing the highest contralateral transmission efficiency of bone vibration is the intermediate frequency range with contralateral direction. Within this range, a significant amplitude of acceleration response is measured at the face-side points and the back and upper parts of the head. The thesis suggests that signal transmission from the specific midline to the mastoid can be more efficient than the conventional configuration of BC from the mastoid to the mastoid.

A Comparison of Ocular Vestibular Evoked Myogenic Potentials via Audiometric and Nonaudiometric Bone Vibrators.

There is limited evidence demonstrating the ability of audiometric bone vibrators to elicit ocular vestibular evoked myogenic potentials (oVEMPs). The RadioEar B71 bone vibrator has insufficient power output to reliably evoke oVEMPs, which has previously left nonaudiometric and nonmedically approved devices such as the Brüel & Kjær Mini-shaker 4810 as the only feasible alternative. The newer RadioEar B81 model has a higher power output than its predecessor, but evidence for its suitability for eliciting oVEMPs has so far been mixed. This variability may be due to factors other than simply the power output, such as whether sufficient static force is applied to hold the transducer in place and transfer vibratory energy into the bone. This study aimed to test the hypothesis that bone-conducted oVEMPs can be obtained with the B81 that are equivalent to those from the Mini-shaker, the de facto gold-standard transducer for this response, when the outputs of the two transducers are matched and they are coupled with sufficient static force. oVEMPs elicited by both transducers were recorded in a counterbalanced within-groups design. Sixteen healthy adults (12 female; 22-47 years) with no history of hearing, balance, or neurological disorders were included in the study. One-cycle alternating tone-burst stimuli at 500 Hz were delivered to the mastoid from each transducer. The vibratory force levels were matched at 127 dB peak-to-peak equivalent force levels, and both were held in place with a static force around 10 N. oVEMP waveforms were gathered from the contralateral eye using the belly-tendon montage and were assessed for statistical equivalence. There was an absence of any statistically significant difference in N10 and N10-P15 amplitudes in oVEMPs from each transducer. Our results indicate that B81 can elicit oVEMPs with no meaningful differences to those from the Mini-shaker, provided effective stimulus levels are matched and static force is sufficient. Although further work is necessary to investigate equivalence at other stimulus frequencies and stimulation sites, the results support the use of the B81 to elicit 500Hz oVEMPs at the mastoid in a clinical setting.

Ankle Audiometry: A Clinical Test for the Enhanced Hearing Sensitivity for Body Sounds in Superior Canal Dehiscence Syndrome

Introduction: The aim of this study was to develop a clinical test for body sounds’ hypersensitivity in superior canal dehiscence syndrome (SCDS). Method: Case-control study, 20 patients affected by SCDS and body sounds’ hypersensitivity and 20 control matched subjects tested with a new test called ankle audiometry (AA). The AA consisted of a psychoacoustic hearing test in which the stimulus was substituted by a controlled bone vibration at 125, 250, 500, and 750 Hz, delivered at the medial malleolus by a steel spring-attached bone transducer prototype B250. For each subject, it was defined an index side (the other being non-index), the one with major symptoms in cases or best threshold for each tested frequency in controls. In 3 patients, the AA was measured before and after SCDS surgery. Results: The AA thresholds for index side were significantly lower in SCDS patients (115.6 ± 10.5 dB force level [FL]) than in control subjects (126.4 ± 8.56 dB FL). In particular, the largest difference was observed at 250 Hz (−16.5 dB). AA thresholds in patients were significantly lower at index side in comparison with non-index side (124.2 ± 11.4 dB FL). The response obtained with 250 Hz stimuli outperformed the other frequencies, in terms of diagnostic accuracy for SCDS. At specific thresholds’ levels (120 dB FL), AA showed relevant sensitivity (90%) and specificity (80%) for SCDS. AA did not significantly correlate to other clinical markers of SCDS such as the bone and air conducted hearing thresholds and the vestibular evoked myogenic potentials. The AA thresholds were significantly modified by surgical intervention, passing from 119.2 ± 9.7 to 130.4 ± 9.4 dB FL in 3 patients, following their relief in body sounds’ hypersensitivity. Conclusion: AA showed interesting diagnostic features in SCDS with significantly lower hearing thresholds in SCDS patients when compared to healthy matched subjects. Moreover, AA could identify the affected or more affected side in SCDS patients, with a significant threshold elevation after SCDS surgery, corresponding in body sounds’ hypersensitivity relief. Clinically, AA may represent a first objective measure of body sounds’ hypersensitivity in SCDS and, accordingly, be an accessible screening test for SCDS in not tertiary audiological centers.

Hearing Through Bone Conduction Headsets.

Bone conduction (BC) stimulation has mainly been used for clinical hearing assessment and hearing aids where stimulation is applied at the mastoid behind the ear. Recently, BC has become popular for communication headsets where the stimulation position often is close to the anterior part of the ear canal opening. The BC sound transmission for this stimulation position is here investigated in 21 participants by ear canal sound pressure measurements and hearing threshold assessment as well as simulations in the LiUHead. The results indicated that a stimulation position close to the ear canal opening improves the sensitivity for BC sound by around 20 dB but by up to 40 dB at some frequencies. The transcranial transmission ranges typically between -40 and -25 dB. This decreased transcranial transmission facilitates saliency of binaural cues and implies that BC headsets are suitable for virtual and augmented reality applications. The findings suggest that with BC stimulation close to the ear canal opening, the sound pressure in the ear canal dominates the perception of BC sound. With this stimulation, the ear canal pathway was estimated to be around 25 dB greater than other contributors, like skull bone vibrations, for hearing BC sound in a healthy ear. This increased contribution from the ear canal sound pressure to BC hearing means that a position close to the ear canal is not appropriate for clinical use since, in such case, a conductive hearing loss affects BC and air conduction thresholds by a similar amount.

Effects of aging on ocular vestibular-evoked myogenic potential using ER-3A insert earphone and B81 bone vibrator

PurposeAging is a process associated with degeneration and dysfunction of peripheral vestibular system or apparatus. This study aimed to investigate the influence of aging on ocular vestibular-evoked myogenic potential (oVEMP) response rates and recording parameters using the B81 bone vibrator and compare them with air conduction stimuli (ACS) oVEMP response characteristics.MethodsIn 60 healthy participants aged 10–71 years (mean age 39.9; 29 male participants), the oVEMP response was elicited using a B81 bone vibrator and an ER-3A insert earphone. The effects of age and stimulus on oVEMP response rates and recording parameters were evaluated.ResultsResponse rates and amplitudes declined with aging using either ACS or bone-conducted vibration (BCV) stimulation, particularly in individuals over 60 years of age, whereas thresholds increased and N1 latencies were prolonged. BCV showed fewer risks of absent oVEMP response than ACS (p = 0.002). BCV acquired higher amplitudes (p < 0.001), lower thresholds, and shorter N1 and P1 latencies (all p < 0.001) than ACS.ConclusionsThe absence of an oVEMP response may be attributed to aging rather than a concurrent vestibular disorder. B81-BCV likely produces higher mechanical drives to the vestibular hair cells at safer and non-traumatic levels compared with ACS and therefore may be more likely to evoke a response in the elderly cohort, whose vestibular function and mechanical sensitivity have declined. Thus, B81-BCV stimulation is more effective and safer to elicit oVEMPs, and it should be recommended when ACS fails in the clinic, particularly in the elderly population.

Cortical Bone Vibrations Induced by Electromagnetic Field Pulse

The purpose of our study was to test the hypothesis that the electromagnetic pulse (EMP) is capable of inducing mechanical vibrations in bone <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ex vivo</i> . A thin segment of human femur diaphysis (from a tissue repository) suspended on a tensioned line (range <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T =$ </tex-math></inline-formula> 2.2–123 N) was exposed to EMP (mean <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$B =0.64$ </tex-math></inline-formula> T, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dB</i> / <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dt</i> = 5877 T/s, and the mean <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$B$ </tex-math></inline-formula> -field gradient of 127 T/m) from a solenoid with axis orthogonal to tensioning line, forming a harmonic oscillator whose mechanical vibrations were measured using laser Doppler vibrometry (LDV, noise floor 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> /s). Calculated mean Maxwell stress and Lorentz forces acting on a weakly conducting, diamagnetic bone slice point away from the solenoid for maximum sensitivity of LDV measurement. The electromechanical origin of the LDV signal was confirmed by the order-of-magnitude agreement between calculated (range from 12 to 50 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> /s) and measured initial bone velocity amplitudes (e.g., <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$35.5~\mu \text{m}$ </tex-math></inline-formula> /s ± <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.5~\mu \text{m}$ </tex-math></inline-formula> /s at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T =22.2$ </tex-math></inline-formula> N and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$17.7~\mu \text{m}$ </tex-math></inline-formula> /s ± <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.5~\mu \text{m}$ </tex-math></inline-formula> /s at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T =58.2$ </tex-math></inline-formula> N) and the increasing frequency (25–180 Hz) of decaying oscillations with the square root of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T$ </tex-math></inline-formula> over the range of line tensions ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$r^{2} =0.978$ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$p &lt; 10^{-4}$ </tex-math></inline-formula> , and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n =17$ </tex-math></inline-formula> ). Theory and experiment show that magnetic field impulses are capable of exerting measurable mechanical forces on bone <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ex vivo</i> . The results raise an interesting question if the electromechanical effect could be sufficiently large to contribute to bone remodeling, reportedly sensitive to vibration amplitudes as small as 1 nm, and considering long duration of orthopedic therapy using repetitive EMP (months).

AMBAND Bone-Conduction Headband.

As bone-conduction thresholds vary with the coupling force between the vibrator and the head, it is important that the coupling force be within the range specified by audiometer standards. The development and validation of AMBAND, an elastic headband for coupling an audiometric bone vibrator to the head, in either the mastoid or forehead position, is described. The headband was constructed from woven, fold-over elastic with Velcro attachment points to produce the proper force on the head for various head sizes. Force measurements were made with a digital force gauge on five artificial heads, representing adult females, adult males, children (age 6 years), infants (age 6 months), and newborns with the bone vibrator in the mastoid and forehead positions. Additional measurements were made with the Radioear P-3333 spring band that is in common use. Force measurements were highly repeatable within a given headband and across headbands. Force measurements for AMBAND were within the range specified by the ANSI S3.6-2018. The Radioear P-3333 spring band produced force levels that exceeded the specified range and had higher variability compared with AMBAND. AMBAND can be used to couple audiometric bone vibrators to the head in the forehead and mastoid positions during bone-conduction testing to provide accurate threshold measurements.

AMBAND Bone-Conduction Headband.

As bone-conduction thresholds vary with the coupling force between the vibrator and the head, it is important that the coupling force be within the range specified by audiometer standards. The development and validation of AMBAND, an elastic headband for coupling an audiometric bone vibrator to the head, in either the mastoid or forehead position, is described. The headband was constructed from woven, fold-over elastic with Velcro attachment points to produce the proper force on the head for various head sizes. Force measurements were made with a digital force gauge on five artificial heads, representing adult females, adult males, children (age 6 years), infants (age 6 months), and newborns with the bone vibrator in the mastoid and forehead positions. Additional measurements were made with the Radioear P-3333 spring band that is in common use. Force measurements were highly repeatable within a given headband and across headbands. Force measurements for AMBAND were within the range specified by the ANSI S3.6-2018. The Radioear P-3333 spring band produced force levels that exceeded the specified range and had higher variability compared with AMBAND. AMBAND can be used to couple audiometric bone vibrators to the head in the forehead and mastoid positions during bone-conduction testing to provide accurate threshold measurements.

A study of the hearing status in the contralateral healthy ear of patients with chronic otitis media following mastoidectomy surgery in a tertiary care hospital, Kerala, India

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Bone drilling and suction during surgeries, exposes cochleae to noise of markedly high levels, temporal bone vibrations to high speeds of drill bits. Variations in burr type and drilling duration can determine extent of noise generated. These may affect cochlea and hearing status of a patient. This study tries to identify hearing loss if any, in the apparently healthy contralateral ear and, the effect of various drill parameters on hearing status in patients with chronic otitis media following mastoidectomy surgery.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Study done using proforma, clinical examination data from operation theatre during surgery and audiology department. Pure Tone Audiometry of apparently healthy contralateral and diseased ears in patients done before surgery, within 24 hrs and 72 hrs after surgery.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Out of 161 patients ,12 patients (7.45%) developed hearing loss post operatively. The mean duration of drilling with cutting burr in the 12 patients with hearing loss was 28 minutes 20 seconds (SD: 1.72) and for diamond burr was 25 minutes and 26 seconds (SD: 2.06). Among the patients with hearing loss, four had multiple frequencies affected (33.3%). There was a statistically significant relation in type of drills used in surgery and hearing loss (p&amp;lt;0.001). In 10 Out of 12 patients, the hearing loss post-surgery, (83.3%) reverted to normal within 72 hrs.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;A positive correlation exists between, transient sensorineural hearing loss that develops post-surgery with the various type of drills used for surgery, which reverted to pre-operative hearing levels within 3 days.&lt;/p&gt;&lt;p class="abstract"&gt; &lt;/p&gt;

Simulation of soft tissue stimulation–Indication of a skull bone vibration mechanism in bone conduction hearing

Soft tissue conduction has been proposed as an alternative to bone conduction (BC) for hearing vibrations applied at soft tissue positions at the human head. Arguments for soft tissue conduction originate primarily from experimental studies with stimulation applied to different positions such as the neck, the eye, and directly to the dura. To investigate the mechanism for hearing when stimulations are at soft tissue positions, experimental studies were replicated using the finite element model for BC research, the LiUHead. The vibrations at the cochlear promontory and the sound pressure in the cerebrospinal fluid (CSF) close to the inner ear were extracted from simulations in the LiUHead. The LiUHead simulations were able to replicate data in the literature of cochlear promontory vibration levels and CSF sound pressures with stimulation applied at the soft tissue positions and at the skin covered mastoid. It was shown that the mechanical point impedance of the soft tissue positions affected the output of the BC transducer at frequencies below 1 kHz. The LiUHead simulated cochlear promontory velocities predicted the soft tissue position's hearing thresholds reported in the literature within the inter-study range. This indicates that the hearing mechanism for stimulation at soft tissue positions equals the hearing mechanism for conventional BC hearing, and that soft tissue conduction is not an alternative hearing mechanism. Moreover, the simulations indicated that the CSF sound pressure is not an important pathway for BC hearing and that the CSF pressure is generated by the local skull bone vibrations.

Comparing the diagnostic accuracy of audiometric Weber test and tuning fork Weber test in patients with conductive hearing loss.

ObjectivesWeber test is typically conducted using tuning forks, but an audiometer can also be used for a similar purpose. Compared to the tuning fork Weber (TFW) test, performing the audiometric Weber (AW) test offers many advantages. Nevertheless, AW and TFW tests' performance compared to pure‐tone audiometry (PTA) has yet to be studied. The present study aimed to determine the accuracy and agreement between the AW and TFW tests compared to PTA.MethodsIn this observational cross‐sectional study, 74 participants (aged 12‐67 years) with unilateral conductive hearing loss (CHL) or bilateral asymmetrical CHL were enrolled. The TFW test was performed according to the established protocol at 256 and 512 Hz. For the AW test, the bone vibrator was placed in the middle of the forehead, where 250 and 500 Hz frequencies were tested. TF and AW test results were then compared with the expected lateralization from the respective PTA results.ResultsAt 256 Hz (or 250 Hz), the overall accuracy values of TFW and AW tests were 81.1% and 86.5%, respectively. At 512 Hz (or 500 Hz), the overall accuracy results of TFW and AW tests were 85.1% and 82.4%, respectively. In addition, the kappa statistics revealed substantial agreements between the two tests and PTA (k = .63‐.72).ConclusionBoth AW and TFW tests are reasonably accurate in assessing patients with CHL. It is recommended for audiologists to perform the simple AW test to verify incomplete or questionable audiograms that are commonly encountered in clinical practice.Level of evidenceLevel 3b.