Mid Frequency Research Articles

Comparison of passive versus active transcutaneous bone anchored hearing devices in the pediatric population

ObjectiveTranscutaneous bone anchored hearing devices (BAHDs) were introduced in an effort to avoid potential complications associated with the abutment of percutaneous BAHDs. Transcutaneous BAHDs can be active or passive. While studies have demonstrated good outcomes with both, a direct comparison of audiological and clinical outcomes of these devices in the pediatric population has not yet been studied.Study designRetrospective, multicenter study.SettingTwo tertiary academic centers.MethodsBetween 2015 and 2019, all patients who received an active transcutaneous BAHD (Bonebridge, BB) at one center, and patients that received a passive transcutaneous BAHD (Attract, AT) at another center, were included in this study. Exclusion criteria included age > 18 years, and mixed hearing loss or single-sided deafness. Study outcomes included patient demographics, indications, complications and preoperative and one-year postoperative audiometric data.ResultsEighteen BB and eight AT patients met the inclusion criteria. The age range was 5–16 years. There were no significant differences in complication outcomes. Both devices demonstrated similar mean improvements in hearing thresholds at frequencies of 250 Hz (38 dB Active vs. 38 dB Passive), 500 Hz (34 dB vs. 42 dB), 1000 Hz (34 dB vs. 40 dB) and 2000 Hz (31 dB vs. 22 dB). The BB was significantly more effective at frequencies of 4000 Hz (28 dB vs. 7 dB) and 8000 Hz (29 dB vs. 6 dB) (p < 0.05).ConclusionThis is the first study comparing audiological outcomes between an active and a passive transcutaneous BAHD in the pediatric population. While both devices improved audiometric outcomes in the low and mid frequencies, the active BAHD demonstrated significantly better outcomes in the higher frequencies.Graphical

Study on Sound Radiation Characteristics and Sound Insulation of Extruded Aluminium Plate

The use of extruded aluminium plates in the subway car body can reduce the weight of the car body, but it will bring about the negative result of increased noise in the car. The extruded aluminium panels belong to rib-stiffened plate structure in which both local short wave deformation and whole long wave deformation coexist. Studying the vibro-acoustic characteristics of this structure helps to effectively control the noise in the car. In this paper, Acoustic model of extruded aluminium plate and equivalent plate were both built up based on the hybrid method of finite element and statistical energy analysis(FE-SEA) and the statistical energy method (SEA) respectively. According to the theory of statistical energy analysis(SEA), the equivalent modelling method of the aluminium extrusion was presented using a single plate This paper focuses on the sound radiation characteristics and sound insulation of extrude and equivalent structures. Results show that no matter what method is used, the calculation of the sound power and sound insulation of the two structures has the same trend. However, the results of the FE-SEA method can capture the natural frequency of the board and be more accurate reflect vibro-acoustic characteristics of extruded aluminium panels in the middle and low frequency. Equivalent plate can well predict the sound radiation characteristics and sound insulation in the mid and high frequency by using the SEA parameters of the aluminium extrusion.

Design of broadband Helmholtz resonator arrays using the radiation impedance method.

This paper describes the design process of a low-frequency sound absorptive panel composed of differently tuned Helmholtz resonators (HRs), considering size and fabrication constraints relevant for applications in the building sector. The paper focuses on cylindrical and spiral resonators with embedded necks that are thin and can achieve high absorption. the mutual interaction between the resonators was modeled based on the radiation impedance method and it plays a key component in enhancing the absorption performance of the array. The differential evolution search algorithm was used to design the resonators and modify their mutual interaction to derive the absorption performance of multiple HR arrays for comparison. Optimizations to the resonator configuration and the neck resistance were implemented to produce a unit panel that has a broadband absorption performance with emphasis on the low to mid frequencies and is thin and light in weight. Unit panels with dimensions of 20 cm×20 cm, consisting of 29 cylindrical HRs designed to absorb in the 25-900 Hz frequency range, were constructed and tested in a custom-built impedance tube. The measured absorption performance of these panels is consistent with the theoretical predictions.

Binaural-cue Weighting and Training-Induced Reweighting Across Frequencies.

During sound lateralization, the information provided by interaural differences in time (ITD) and level (ILD) is weighted, with ITDs and ILDs dominating for low and high frequencies, respectively. For mid frequencies, the weighting between these binaural cues can be changed via training. The present study investigated whether binaural-cue weights change gradually with increasing frequency region, whether they can be changed in various frequency regions, and whether such binaural-cue reweighting generalizes to untrained frequencies. In two experiments, a total of 39 participants lateralized 500-ms, 1/3-octave-wide noise bursts containing various ITD/ILD combinations in a virtual audio-visual environment. Binaural-cue weights were measured before and after a 2-session training in which, depending on the group, either ITDs or ILDs were visually reinforced. In experiment 1, four frequency bands (centered at 1000, 1587, 2520, and 4000 Hz) and a multiband stimulus comprising all four bands were presented during weight measurements. During training, only the 1000-, 2520-, and 4000-Hz bands were presented. In experiment 2, the weight measurements only included the two mid-frequency bands, while the training only included the 1587-Hz band. ILD weights increased gradually from low- to high-frequency bands. When ILDs were reinforced during training, they increased for the 4000- (experiment 1) and 2520-Hz band (experiment 2). When ITDs were reinforced, ITD weights increased only for the 1587-Hz band (at specific azimuths). This suggests that ILD reweighting requires high, and ITD reweighting requires low frequencies without including frequency regions providing fine-structure ITD cues. The changes in binaural-cue weights were independent of the trained bands, suggesting some generalization of binaural-cue reweighting.

Spatial reconstruction of sound fields using local and data-driven functions.

Sound field analysis methods make it possible to characterize and reconstruct a sound field from a limited set of observations. Classical approaches rely on the use of analytical basis functions to model the sound field throughout the observed domain. When the complexity of the sound field is high, for example, in a room at mid and high frequencies, propagating wave representations can be suboptimal due to model discrepancy. We examine the use of local representations to alleviate this model discrepancy and explore data-driven approaches to obtain suitable models. Specifically, local representations are used to reconstruct the sound field over a large spatial aperture in a room. The performance of local models is compared against conventional plane wave reconstructions and the use of data-driven local functions is examined. Dictionary learning and principal component analysis are used to obtain functions from extensive spatial measurements in an empty room. The results indicate that local partitioning models conform to fields of high spatial complexity. Dictionary learning generalizes across different rooms and frequencies-conferring potential for modelling complex sound fields based on their local and statistical properties.

Regularity criteria for 3D Navier–Stokes equations in terms of a mid frequency part of velocity in B˙-1 ∞,∞

Abstract We prove that a Leray–Hopf weak solution u to 3D Navier–Stokes equations is regular in ( 0 , T ] {(0,T]} if the L 1 ⁢ ( 0 , T ; B ˙ ∞ , ∞ - 1 ) {L^{1}(0,T;\dot{B}^{-1}_{\infty,\infty})} - or L 2 ⁢ ( 0 , T ; B ˙ ∞ , ∞ - 1 ) {L^{2}(0,T;\dot{B}^{-1}_{\infty,\infty})} -norm of u k / 2 , k {u_{k/2,k}} , the mid frequency part of Fourier modes k 2 ≤ | ξ | &lt; k {\frac{k}{2}\leq|\xi|&lt;k} , is small depending on the kinematic viscosity ν, initial value u 0 {u_{0}} and the maximum of an averaged energy dissipation rate A ≡ sup t ∈ ( 0 , T ) ⁡ ( ν ⁢ t - 1 ⁢ ∫ 0 t ∥ ∇ ⁡ u ∥ 2 ⁢ 𝑑 τ ) A\equiv\sup_{t\in(0,T)}\biggl{(}\nu t^{-1}\int_{0}^{t}\lVert\nabla u\rVert^{2}% \,d\tau\biggr{)} for some k ≥ k 0 ⁢ ( ν , u 0 , A ) {k\geq k_{0}(\nu,u_{0},A)} . In particular, when a sufficiently high frequency part of u 0 {u_{0}} decays fast at an exponential rate, then we obtain regularity conditions in terms of smallness of the L 1 ⁢ ( 0 , T ; B ˙ ∞ , ∞ - 1 ) {L^{1}(0,T;\dot{B}^{-1}_{\infty,\infty})} - or L 2 ⁢ ( 0 , T ; B ˙ ∞ , ∞ - 1 ) {L^{2}(0,T;\dot{B}^{-1}_{\infty,\infty})} -norm of u k / 2 , k {u_{k/2,k}} , which involve only the known data ν and u 0 {u_{0}} .

Laminated wood composite design with improved acoustic properties

Next-generation laminated wood composites were produced using waste poplar (Populus deltoides) veneer and polyvinyl acetate adhesive. Four experimental groups and one control group were created. Ten-layer laminated wood veneer samples were reinforced with natural rubber (Group A), linoleum (Group B), felt (Group C), and elastomeric sponge (Group D); these materials were used in the fifth adhesive layer (middle layer). The sound absorption coefficients of the control and experimental groups were tested via the impedance tube method, according to ASTM standard E1050 (2006). Attention was paid to the acoustic behavior at low frequencies (63 Hz to 250 Hz), mid frequencies (250 Hz to 2000 Hz), and high frequencies (2000 Hz to 6300 Hz). It was determined that the sound absorption coefficient of the experimental groups considerably increased. It can be suggested that the experimental groups be used as sound absorbing acoustic panels and the control group as sound reflective acoustic panels.

Opto‐Electromagnetics and Resonance Activities of Oxalic Acid Embedded Manganese and Cadmium‐Mixed Crystals

AbstractManganese‐mixed barium oxalate (MMBO) and cadmium‐mixed zinc oxalate (CMZO) crystals are fabricated using a gel technique. The foregrounded crystals are characterized by spectroscopic and analytical techniques. Chemical constituents, cationic distribution, functional groups, thermal stability, and degradation behavior of MMBO and CMZO crystals are explored in succession with the aid of energy‐dispersive X‐ray analysis, Fourier transform infrared spectroscopy and thermogravimetric analysis respectively. MMBO crystal embeds a molecular weight of 223.419 (chemical formula Mn0.4607Ba0.5394C2O42H2O), whereas CMZO ingrains by a molecular weight of 212.656 (chemical formula Zn0.6976Cd0.3024C2O42.5H2O). Both the crystals possess band gap energies (Eg ≈ 6 eV), large dielectric constant, leakage resistance in GΩ, capacitance in pF, excellent thermal stability (890 °C), opaqueness to electrical current and paramagnetic (MMBO)/diamagnetic behaviors (CMZO). Surprisingly, in response to alternating emf, crystal capacitors of MMBO and CMZO exhibit very sharp resonance throws at mid radio frequency range showcasing quartz‐like extremely high quality factor. Distinct optoelectric behavior, outstanding thermal stability and special resonance dynamics signal unique applications in communication–micro‐high‐temperature electronics.

Development of an intelligent laser biospeckle system for early detection and classification of soybean seeds infected with seed-borne fungal pathogen (Colletotrichum truncatum)

There is a need for developing rapid and non-destructive techniques for the early detection of seed-borne fungal pathogen because they can be an essential step towards adopting effective disease control measures. Existing techniques for detecting seed-borne diseases have poor sensitivity towards early stages of pathogen development (i.e., when seeds are asymptomatic) and they are also expensive, time-consuming, complex, require mycological skills and destructive testing operations. Aiming at overcoming the above limitations of the existing techniques, a novel laser biospeckle based method is proposed for early detection of seed-borne fungal infection in conjunction with machine learning. Soybean seeds infected by low concentrations (102-106 spores ml−1) of Colletotrichum truncatum were analysed by using full field biospeckle analysis to establish the possible relationship between biological activity in early stages of pathogen infection, with and without the use of frequency filtering. The results demonstrate that the biospeckle activity (BA), for both, raw and frequency filtered data was significantly high (p < 0.05) for the diseased seeds even for low inoculum concentrations. Moreover, the amplitude values of mid frequency spectral components for diseased seeds were higher than those of lower and higher spectral components which correspond to the BA of fungal infected seeds. Several classical machine learning algorithms were trained to model the response of healthy and diseased samples after parameter optimisation. Obtained results showed that k-nearest neighbour (k-NN), decision tree (DT), and artificial neural network (ANN) based predictive models presented strong robustness and high performance with overall accuracy reaching up to 96.94% for classifying diseased seeds.

Potential noise annoyance from ambient air quality measurement using high volume air sampler (HVAS)

One of the benchmarks in air pollution is the quality of ambient air consisting of gas and particulate matter. Measurement of particulates in ambient air can be done using a High-Volume Air Sampler (HVAS). However, in the measurement process it sometimes causes noise annoyance to the community where the measuring instrument is operated, considering that the operating time of the instrument is 24 consecutive hours. This research identifies the value of the sound power level emitted from the several types of HVAS to the surrounding environment. There are two types of HVAS measured in this study consisting of one unit of HVAS with analogue flow control made by Indonesian manufacturer and two units of HVAS with digital flow control made by Japan and United States of America manufacturers. Sound power level is determined using ISO 9614 method with a sound intensity analyzer as the main instrument. The sound power level data for each HVAS were than compared and frequency spectrum distributions are evaluated. Based on the research results, it was found that some sample units emitted sound power levels of more than 90 dBA with dominant noise being at high frequencies starting from 4000 Hz. The results of the research can be used as an early information in the development of the HVAS regarding noise mitigation, because there is different approach for controlling noise specifics in low, mid and high frequencies noise source.

20.5 Preliminary Evidence for Associations of the Infant Gut Colonization With Parent-Infant Relationship, Maternal Depression, Stress, and Parenting Styles

The objectives of this presentation are to: 1) examine associations among infant gut colonization based on microbiome measurements in the infant population and maternal depressive symptoms and distress; 2) examine associations among infant microbiome and parent-infant interactions during a vaccination procedure; and 3) examine how infant cries correlate with their microbiome at 4 months of age. For this pilot study, we recruited a prospective cohort of infants (n = 31) and parents (n = 31). We examined the association between the infant gut microbiome at 4 months during well-child visits (WCVs), maternal depression (by Patient Health Questionnaire-9 [PHQ-9]), parent and child characteristics and life stress (by Parenting Stress Index [PSI-IV]), and parent-infant interactions (by Measure of Adult and Infant Soothing and Distress [MAISD]). For each of the variables, we looked at 3 types of associations to identify the component of the microbiome revealed by whole-genome shotgun sequencing: β-diversity (via Bray-Curtis [BC] and Jaccard distances), α-diversity (via Shannon and Inverse-Simpson indexes), and differential abundance (via linear models for differential abundance [LinDA]). Infant cries in response to vaccination were assessed for spectral characteristics, with higher frequencies being associated with greater stress response (mid frequency: 1000-5000 Hz, high frequency: 5000 Hz+). Taxonomic classification identified 19 phyla, 417 genera, and 1246 species. The PHQ-9 scores obtained at 2 months were associated with 4 bacterial species (Ruminococcus flavefaciens, Actinomyces johnsonii, [Clostridium] dakarense, and Bilophila wadsworthia; false discovery rate [FDR] < 0.1) and β-diversity (p = 0.006-BC; p = 0.005-Jaccard). Infant cries with greater high-frequency band power (p < 0.03) and a greater high-to-mid frequency ratio metrics (p < 0.05) associated with higher infant stress were related to lower α-diversity. There were no correlations between PHQ-9 at 4 months, PSI-IV, and microbiome diversity. Data from our study point to a connection between higher perception of stress in infants reflected in their cries and lower microbiome diversity (higher diversity more desirable). We found that parental depressive symptoms influenced their infants’ microbiome. More studies are needed to explore ways in which the quality of the infant-caregiver relationship influences intestinal microbiota.

Measurement verification of reverberation time in seating areas close to the lateral wall in the auditorium

This study started with building a database for existed Jockey Club Auditorium. Using impulse response method to measure numerous seats which cover the whole auditorium. Reverberation time distributed in four range parameters simply look up the hall acoustic performance visualizing by chromatogram. With the hall geometric data and the first lateral reflection path difference calculated from the point of source and receiver in seating areas close to lateral wall, The measurement shows in bass and middle frequency, Early delay time and T20 and T30 exists large fluctuation which reveals seat-dip effect in the front seat area. While in mid and high frequency, T30 presents stable values indicating the direct sound and lateral reflection are predominant in early sound attenuation. Computer simulation is using Pachyderm Acoustical Simulation plug-in based on parametric architectural design software Rhino. Sound attenuation can be calculated with surface shapes defined surface transform efficiency by diffracting energy. However, Reverberation time differences still exist by comparing actual measurement and computer simulation results.

The sensitivity and specificity of wideband absorbance measure in identifying pathologic middle ears in adults living with HIV.

BackgroundLimited research exists on the sensitivity and specificity of wideband acoustic immittance (WAI) in adults living with human immunodeficiency virus (HIV). This study forms part of the bigger study titled ‘wideband acoustic immittance in adults living with HIV’.ObjectivesTo determine the sensitivity and specificity of the wideband absorbance measure at tympanic peak pressure (TPP), as a screening tool for detecting middle ear pathologies in adults living with HIV.MethodA prospective nonexperimental study comprising 99 adults living with HIV was performed. All participants underwent a basic audiological test battery which included case history, video otoscopy, tympanometry, wideband absorbance at TPP and pure tone audiometry. Middle ear pathologies were established by two otorhinolaryngologists using asynchronous video otoscopic images analysis. The outcomes of the otorhinolaryngologists served as the gold standard against which the wideband absorbance at TPP and tympanometry were measured. The receiver operating characteristics (ROC) curve was calculated.ResultsROC revealed the sensitivity of wideband absorbance at TPP to be higher in low to mid frequencies, but significantly lower in frequencies above 971.53 Hz. The sensitivity of tympanometry was lower. However, there was no difference between the specificity of wideband absorbance at TPP and tympanometry, indicating that when there are no pathologies, tympanometry is equally accurate.ConclusionThe current findings reveal that wideband absorbance at TPP can distinguish middle ear pathologies better than the tympanometry. Incorporating wideband absorbance at TPP in clinical practice may improve early identification and intervention of middle ear pathologies.

A Vehicle Pass-by Noise Prediction Method Using Ray Tracing with Diffraction to Extend Simulation Capabilities to High Frequencies

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Predicting Vehicle Pass-by noise using simulation enables efficient development of adequate countermeasures to meet legislative targets while reducing development time and the number of physical trial-and-error prototypes and tests. It has already been shown that deterministic simulation methods such as the Boundary Element Method (BEM), which may also include directivity of sources, can support the trim package optimization process for Pass-by noise, especially for low to mid frequencies. At higher frequencies, the Ray Tracing technique, can represent an efficient alternate providing options to trade off speed versus accuracy compared to wave-based technique such as FE/BEM. This paper presents a Ray Tracing approach with high order diffraction effect. Moreover, source directivity and sound package effect are accounted for. Validation examples for predicting Pass-by noise which complements other deterministic methods and extends practical prediction capabilities to higher frequencies are presented.&lt;/div&gt;&lt;/div&gt;

Restoration of High Frequency Auditory Perception After Robot-Assisted or Manual Cochlear Implantation in Profoundly Deaf Adults Improves Speech Recognition.

Background and Purpose: Robot-assisted cochlear implantation has recently been implemented in clinical practice; however, its effect on hearing outcomes is unknown. The aim of this preliminary study was to evaluate hearing performance 1 year post-implantation whether the electrode array was inserted manually or assisted by a robot.Methods: Forty-two profoundly deaf adults were implanted either manually (n = 21) or assisted by a robot (RobOtol®, Collin, Bagneux, France) with three different electrode array types. Participants were paired by age, and electrode array type. The scalar position of the electrode array in the cochlea was assessed by 3D reconstruction from the pre- and post-implantation computed tomography. Pure-tone audiometry and speech perception in silence (percentage of disyllabic words at 60 dB) were tested on the implanted ear 1 year post-implantation in free-field conditions. The pure-tone average was calculated at 250–500–750 Hz, 500–1,000–2,000–3,000 Hz, and 3,000–4,000–8,000 Hz for low, mid, and high frequencies, respectively.Results: One year after cochlear implantation, restoration of the high-frequency thresholds was associated with better speech perception in silence, but not with low or mid frequencies (p < 0.0001; Adjusted R2 = 0.64, polynomial non-linear regression). Although array translocation was similar using either technique, the number of translocated electrodes was lower when the electrode arrays had been inserted with the assistance of the robot compared with manual insertion (p = 0.018; Fisher's exact test).Conclusion: The restoration of high-frequency thresholds (3,000–4,000–8,000 Hz) by cochlear implantation was associated with good speech perception in silence. The numbers of translocated electrodes were reduced after a robot-assisted insertion.

Shannon entropy measures for EEG signals in tinnitus

Background and AimTinnitus is known as a common clinical symptom, and it comprehensively is essential to understand the underlying mechanisms. Time-varying EEG is considered an appropriate technique to explore brain regions and related activities, and nonlinear methods may extract the irregularities in the EEG signal and gather more expanded information. Therefore, we studied Shannon Entropy in EEG raw data obtained from normal subjects and compared it to data from chronic tinnitus sufferers before and after an intervention. MethodsFrom the qEEG database of Iran University of Medical Sciences, the School of Rehabilitation Sciences, we have selected 23 healthy and 24 chronic tinnitus subjects. Nineteen subjects of the tinnitus group had benefited from a complete course of sound therapy (binaural beat for a month). QEEGs were measured with a 27-channel EEG amplifier in the sitting and eye-closed position for 3 min. Shannon entropy was investigated for all electrodes separately and compared among groups using a one-way ANOVA statistical test. FindingsOur results revealed a significant difference between healthy and tinnitus subjects (p < 0.05). Post-hoc comparisons using the Bonferroni test showed increased entropy in the tinnitus group for all electrodes (p < 0.05) at low frequencies and most electrodes at mid frequencies. In addition, after the intervention, paired t-test showed a reduction in entropy to somehow above normal control levels for all electrodes at low-frequencies. Such results were accompanying clinical improvement after the intervention. ConclusionThe increased entropy in tinnitus patients might reflect the chaotic behavior of the brain. Nonlinear methods in EEG studies (Entropy) could be of great importance in understanding tinnitus neurophysiology and might potentially be a suitable criterion for clinical practice.

AN OBSERVATIONAL STUDY OF HEARING THRESHOLDS IN PROFESSIONAL DRIVERS

Introduction: Noise has become a very important stress factor in the environment. Drivers are the most commonly affected persons due to trafc noise. The majority of drivers remain unaware about noise induced hearing loss as this is an insidious process, leading to temporary or permanent hearing impairment, but preventable. Pure Tone audiometric test is used to determine the degree of hearing loss in noise exposed individuals. Aim &amp; Objective: To nd the hearing threshold levels for high and mid frequency sounds for both ears in Professional drivers. To evaluate the preponderance of hearing loss between right and left ear using hearing thresholds. Materials &amp; Methods: This study was conducted in 100 Professional male drivers aged between 30-40 years who are working in Tamil Nadu State Transport Corporation, Madurai. Pure tone audiometry was used to measure the high and mid frequency hearing threshold levels in both ears. Results: The mean (SD) hearing threshold for high and mid frequency sounds was signicantly higher in left ear comparative to right ear with P value &lt; 0.05. The statistically signicant difference in hearing loss was observed between both ears. Conclusion : Our study showed statistically signicant higher hearing threshold for high and mid frequency sounds in left ear compared to right ear, that concludes left ear is more prone for hearing loss than the right ear

Sensor placement for sound field reconstruction in enclosures.

Sampling spatio-temporal acoustic fields is a challenging problem since it demands a large number of sensors. Typically, to characterize the pressure field inside an enclosure, the number of measurements required increases linearly with frequency and cubically with volume, becoming an intractable problem for rooms of moderate size even at low and mid frequencies. Sparse representation techniques, such as Compressed Sensing, rely on the sparsity of natural signals in certain representation domain to drastically reduce the number of measurements needed to sample such signals. In this study, we optimize the placement of sensors inside an enclosure in order to reduce the measurements required for a given reconstruction accuracy. The proposed methodology selects a sparse set of sensor positions from predefined grid via the QR factorization of the sensing matrix. Numerical results show an effective reduction in the required number of measurements when their positions are optimized, in contrast to standard random positioning. Unlike the majority of existing approaches, we study the placement problem for wide-band acoustic fields.

Análisis de la potencia de salida y del rendimiento auditivo de los dispositivos auditivos osteointegrados

Background and objectiveOsseointegrated auditory devices are hearing gadgets that use the bone conduction of sound to produce hearing improvement. The mechanisms and factors that contribute to this sound transmission have been widely studied, however, there are other aspects that remain unknown, for instance, the influence of the processor power output. The aim of this study was to know if there is any relationship between the power output created by the devices and the hearing improvement that they achieve. Materials and methodsForty-four patients were implanted with a percutaneous Baha® 5 model. Hearing thresholds in pure tone audiometry, free-field audiometry, and speech recognition (in quiet and in noise) were measured pre and postoperatively in each patient .The direct bone conduction thresholds and the power output values from the processors were also obtained. ResultsThe pure tone average threshold in free field was 39.29dB (SD 9.15), so that the mean gain was 29.18dB (SD 10.13) with the device. This involved an air-bone gap closure in 63.64% of patients. The pure tone average threshold in direct bone conduction was 27.6dB (SD 10.91), which was 8.4dB better than the pure tone average threshold via bone conduction. The mean gain in speech recognition was 39.15% (SD 23.98) at 40dB and 36.66% (SD 26.76) at 60dB. The mean gain in the signal-to-noise ratio was −5.9dB (SD 4.32). On the other hand, the mean power output values were 27.95dB μN (SD 6.51) in G40 and 26.22dB μN (SD 6.49) in G60. When analysing the relationship between bone conduction thresholds and G40 and G60 values, a correlation from the frequency of 1,000Hz was observed. However, no statistically significant association between power output, functional gain or speech recognition gain was found. ConclusionsThe osseointegrated auditory devices generate hearing improvement in tonal thresholds and speech recognition, even in noise. Most patients closed the air-bone gap with the device. There is a direct relationship between the bone conduction threshold and the power output values from the processor, but only in mid and high frequencies. However, the relationship between power output and gain in speech recognition is weaker. Further investigation of contributing factors is necessary.

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