Hearing Aid Device Research Articles

Determinants Analysis of Satisfaction with Supporting System for Hearing Aids

Background and Objectives Hearing disability has a negative impact on the psychological condition and the quality of life of patients, as well as their daily lives. This study tries to identify the relationship between personal perception of the national supporting system for hearing aids and the satisfaction of the supporting system on the part of users, suppliers and specialists. Subjects and Method A total of seven questions were developed to identify factors that can affect the satisfaction of national supporting system for hearing aids. We surveyed hearing aids users, suppliers, and specialist; the final sample included 455 subjects. Results Determinants of satisfaction were adequacy of accepted durability of hearing aids, accessibility to relevant information, necessity of graded financial support by type of hearing aids, necessity of supporting repair cost and necessity of graded financial support by kind of disability rating. According to the results of multiple logistic regression analysis, subjects who answered that accepted durability of hearing aids [odd ratio (OR): 2.03, confidence interval (CI): 1.14-3.60] and accessibility to information (OR: 4.82, CI: 2.65-8.78) were proper showed tendency to be satisfied with support system for hearing aids. The subjects who answered that graded financial support by kind of hearing aids (OR: 1.98, CI: 1.10-3.59) and graded financial support by kind of disability rating (OR: 1.91 CI: 1.07-3.42) were necessary showed tendency to satisfy with support system for hearing aids. Conclusion In order to enhance satisfaction in stakeholder perceptions of supporting system for hearing aids, the system needs provide users with better access to relevant information and help in the use and management of the hearing-aid device. Key words: Hearing aids ㆍ Hearing impairment ㆍ Insurance coverage ㆍ Personal satisfaction

Objective assessment of perceived effort in listening by employing EEG feature.

The adjustment of hearing aid devices can heavily depend on the subjective feedback of the patients. Our aim is to investigate measures that can be used objectively to state a subject's listening effort. To obtain a comprehensive and reliable measure as an indicator for a person's listening effort, we need to have a better understanding of electroencephalograpic (EEG) activities. Decoding EEG signals specifically by the analysis of the instantaneous phase information has been a new trend in the last decades. Throughout many studies conducted in the past, it has been shown that the instantaneous phase of oscillatory signals reset in relation to various cognitive processes. This is based on a hypothesis presented for the generation of event related potentials. In this study, we measure the degree of phase re-organization through fitting a von Mises distribution to EEG recordings. The concentration parameter of a von Mises distribution has been shown as an informative feature for reflecting the level of attention. This feature has been used for predicting the listening effort and the results are compared among three different hearing aid settings.

Fully integrated, low drop-out linear voltage regulator in 180 nm CMOS

This paper presents a capacitor-free low dropout (LDO) linear regulator based on a dual loop topology. The regulator utilizes two feedback loops to satisfy the challenges of hearing aid devices, which include fast transient performance and small voltage spikes under rapid load-current changes. The proposed design works without the need of a decoupling capacitor connected at the output and operates with a 0---100 pF capacitive load. The design has been taped out in a $$0.18\,\upmu \hbox {m}$$0.18μm CMOS process. The proposed regulator has a low component count, area of $$0.012\, \hbox {mm}^2$$0.012mm2 and is suitable for system-on-chip integration. It regulates the output voltage at 0.9 V from a 1.0---1.4 V supply. The measured results for a current step load from 250 to 500 $$\upmu \hbox {A}$$μA with a rise and fall time of $$1.5\,\upmu \hbox {s}$$1.5μs are an overshoot of 26 mV and undershoot of 26 mV with a settling time of $$3.5\,\upmu \hbox {s}$$3.5μs when $${C_L}$$CL between 0 and 100 pF. The proposed LDO regulator consumes a quiescent current of only $$10.5\,\upmu \hbox {A}$$10.5μA. The design is suitable for application with a current step edge time of 1 ns while maintaining $$\Delta V_{out}$$ΔVout of 64 mV.

Demodulation of quasi-quadrature interferometric signals for use in the totally implantable hearing aids.

We propose and experimentally prove an algorithm for demodulation of interferometric signals, modified for use in a totally implantable hearing aid device. A fiber optic configuration, which generates two quasi-quadrature signals by a passive 3x3 coupler, for a non-contact detection of the middle ear ossicle vibration is employed. We simulated the ossicle vibration and large movements and demonstrated the effectiveness of the algorithm to compensate changes of the signal DC values and the phase shift introduced by the coupler. Applying the proposed algorithm we obtained the output signal stability better than 0.5 dB, and the system equivalent input noise of about 31 dB (A) SPL @ 1 kHz.

Estimation of speech source direction for hearing aid application using smartphone

In our hearing aid research project funded by NIH-NIDCD we utilize smartphone and its features as a powerful platform to implement complex signal processing algorithms which would improve hearing aid applications. Among the required algorithms, is finding the direction of arrival of speech source signals which can improve the performance of hearing aid devices for the users. In this poster presentation, a signal processing algorithm for estimating the speech source direction and its real-time implementation on an Android smartphone are demonstrated. The visual display of source direction on the smartphone panel can be used to align the phone and its two microphones in the right direction of source to enhance the signal to noise ratio and improve the reception of speech signal. A demo unit will be presented showing the real-time operation of the proposed method on an Android smartphone.

Hearing impairments, presbycusis and the possible therapeutic interventions

The hearing is an important sensation of all living organism to maintain his or her life mainly in human. Any distortion to it leads to hearing impairment. Hearing loss (HL) can be congenital or acquired. It can be syndromic; HL associated with other abnormalities or non-syndromic, HL is not associated with any other anomalies. Hearing impairment have mostly autosomal recessive loci, but can be autosomal dominant, X-linked, and mitochondrial. Acquired HL can be genetic or environmental factors based. Age-related HL is acquired hearing loss occur in aged population. Its prevalence rate increases with age. Genetic of presbycusis is not well-known, but NAT2*6A polymorphism, SNPs in KCNQ4, grainy head-like 2 gene, Glutamate receptor-7 gene, 4977-bp mt-DNA deletion in human and 4834-bp mtDNA deletion in rodents were identified. Different strains of mice are developed like C57BL/6J, CBA/CaJ, DBA/2J, BALB/cJ and Fisher 344 albino rats mainly used as models to study HL and presbycusis. Like other disorders have complete treatment, but HL cannot be completely treated. However some attempts can be made for its betterment by using hearing aid devices, surgical and pharmaceutical treatments. In future stem cells and gene therapy will be the affective methods to treat congenital hearing impairment and presbycusis.

Sound generator associated with the counseling in the treatment of tinnitus: evaluation of the effectiveness

IntroductionThe relations between the tinnitus and the hearing loss are due to the sensory deprivation caused by hearing loss, since this is followed by the functional and structural alteration of the auditory system as a whole. The cochlear lesions are accompanied by a reduction in the activity of the cochlear nerve, and the neural activity keeps increased in mainly all the central auditory nervous system to compensate this deficit. ObjectiveThis study aimed to verify the effectiveness of the sound generator (SG) associated with the counseling in the treatment of the tinnitus in individuals with and without hearing loss regarding the improvement of the nuisance through Tinnitus Handicap Inventory (THI) and Visual Analogue Scale (VAS). MethodsThe sample consisted of 30 individuals of both genders divided into two groups: Group 1 (G1) was comprised of 15 individuals with tinnitus and normal hearing, adapted to SG; Group 2 (G2) was comprised of 15 individuals with complaints of hearing acuity and tinnitus, adapted with SG and an individual hearing aid device (HA). Both groups underwent the following procedures: anamnesis and history of complaint, high frequency audiometry (HFA), imitanciometry, acuphenometry with the survey of psychoacoustic pitch and loudness thresholds and application of the tools THI and VAS. All of them were adapted with HA and Siemens SG and participated in a session of counseling. The individuals were assessed in three situations: initial assessment (before the adaptation of the HA and SG), monitoring and final assessment (6 months after adaptation). ResultsThe comparison of the tinnitus nuisance and handicap in the three stages of assessment showed a significant improvement for both groups. ConclusionThe use of the SG was similarly effective in the treatment of the tinnitus in individuals with and without hearing loss, causing an improvement of the nuisance and handicap.

A Probabilistic Modeling Approach to Hearing Loss Compensation

Hearing Aid (HA) algorithms need to be tuned ("fitted") to match the impairment of each specific patient. The lack of a fundamental HA fitting theory is a strong contributing factor to an unsatisfying sound experience for about 20% of hearing aid patients. This paper proposes a probabilistic modeling approach to the design of HA algorithms. The proposed method relies on a generative probabilistic model for the hearing loss problem and provides for automated inference of the corresponding (1) signal processing algorithm, (2) the fitting solution as well as a principled (3) performance evaluation metric. All three tasks are realized as message passing algorithms in a factor graph representation of the generative model, which in principle allows for fast implementation on hearing aid or mobile device hardware. The methods are theoretically worked out and simulated with a custom-built factor graph toolbox for a specific hearing loss model.

Low-noise and small-area integrated amplifier circuit for mems-based implantable hearing aid applications

Hearing aid devices are used by patients with hearing impairment to help with hearing problems. These devices consist of a microphone, an amplifier, and speaker modules. The author previously developed a micro-electromechanical piezoelectric diaphragm for a hearing aid device. The proposed diaphragm was in circular shape with 700 μm diameter and 10 μm thickness using AlN piezoelectric material. The design was performed in MEMS scale to offer maximum performance by the diaphragm for the human hearing frequency range. Adding to the previous work, in the present paper, a voltage amplifier circuit is designed for that piezoelectric microphone. The design is performed with respect to suitable circuit performance for the 5 Hz---22.5 kHz frequency range, small area, low noise, high gain and integration capability between the circuit and the diaphragm. The designed circuit is modeled and implemented in Cadence based on the 180 nm (0.18 μm) CMOS technology standard and the circuit layout is demonstrated with the circuit occupying an area of 0.08 mm × 0.04 mm. Simulation study is performed for assessment of the performance of the circuit. The results indicate that the frequency range of the amplifier covers the audio frequency of 5 Hz---22.5 k Hz, the amplification gain is 84.78 dB with the phase margine (PM) of 75.95°, the average power consumption of 0.216 mW, the Input noise level of 4.19 μVrms, CMRR of 133.69 dB and PSRR of 98.76 dB. The integration of the circuit with the microphone for hearing aid devices is proposed based on circuit binding method.

Wideband audio systems for hearing aid devices

Multi-loudspeaker design has been one of the most widely used methods for improving the sound quality of audio systems. Some of the electroacoustic design concepts defined for typical earphones can be used for other wideband miniature audio systems as well. However, wideband audio for hearing aid devices and smart earphones introduce new design factors. Efficiency and transducer size are among the factors that become important in the electroacoustic design. In this paper, the electroacoustic design factors for woofer-tweeter audio systems are revisited and discussed for hearing aid devices. Simulation and measurement results are presented and analyzed.

Automatic switching between noise classification and speech enhancement for hearing aid devices.

This paper presents a voice activity detector (VAD) for automatic switching between a noise classifier and a speech enhancer as part of the signal processing pipeline of hearing aid devices. The developed VAD consists of a computationally efficient feature extractor and a random forest classifier. Previously used signal features as well as two newly introduced signal features are extracted and fed into the classifier to perform automatic switching. This switching approach is compared to two popular VADs. The results obtained indicate the introduced approach outperforms these existing approaches in terms of both detection rate and processing time.

Smartphone-based noise adaptive speech enhancement for hearing aid applications.

It is well established that the presence of environmental noises has a negative impact on the performance of hearing aid devices. This paper addresses a noise adaptive speech enhancement solution for the purpose of improving the performance of hearing aid devices in noisy environments. Depending on three noise types of babble, machinery, and driving car, the parameters of a recently developed speech enhancement algorithm are appropriately adjusted to gain improved speech understanding performance in noisy environments. This solution is implemented on smartphone platforms as an app and interfaced with a hearing aid device. A clinical testing protocol is devised to evaluate the performance of the app in participants with normal hearing and hearing impairments. The clinical testing results have indicated that statistically significant improvement in speech understanding is gained between the unprocessed and processed conditions using the developed noise adaptive speech enhancement solution.

An Appraisal of the Advancement of Emerging Technologies in Hearing Aids

Background/Objectives: To shed light on the history of development of hearing aid, along with the various pros and cons of each developed technological solution. Methods/Statistical Analysis: A historical survey has been conducted, which highlights some of the more renowned and widely deployed hearing aids within the market. The different types of hearing losses and the varying degree of assistance provided by the different technological solutions have been discussed. Over the years, the overall accuracy as well as practicality of the hearing aids have improved, ranging from cumbersome and heavy hearing aids in the early 1960-1970s to the portable and wearable ones available in the market at present. Findings: Technological innovation is spearheading massive improvement within the hearing aids. Some of the key features causing these changes include wireless technology, frequency lowering, directional microphones and digital noise reduction algorithms. Although DSP has provided significant changes in the hearing technology, limitations still exist, which require re-search contributions from different fields like clinical audiology, psychoacoustics and signal processing. Application/Improvements: Most of the portable and reliable hearing aid devices are very expensive. Therefore, there is a need to develop affordable pieces of equipment that is able to cater to basic hearing functionalities.

Clinical evaluation of an over-the-counter hearing aid (TEO First®) in elderly patients suffering of mild to moderate hearing loss.

BackgroundPresbycusis has a direct influence on autonomy of the elderly but hearing aids lack of affordability. Moreover a recent review demonstrate that electroacoustic characteristics of OTC hearing aids were generally not suitable for the elderly people. In our study, we assessed the clinical value of a new over-the-counter (OTC) hearing aid device (TEO First®) in the elderly.MethodThis prospective monocentric open label study included patients over 60 years of age with a mild to moderate presbycusis. Patients were assessed with acceptable noise level test (ANL), pure tone (PTA) and speech (SA) audiometry in silent and noisy environment, with and without TEO First®. A Glasgow Hearing Aid Benefit Profile, acceptability and satisfaction surveys were completed after one month of using the device.ResultsThirty one patients were included. There was an improvement of hearing with TEO First® in silence (SA: +39.2 %, p < 0.01; PTA: -9.04 dB, p < 0.01) or in noise (SA +47.7 %, p < 0.01; PTA: -5.23 dB, p < 0.05). After one month of use of the device, quality of life has improved with regards to the following parameters: decrease of perceived hearing difficulties during conversation without background noise (-9.6 % p = 0.018), in conversation with several people (-16.2 % p = 0.0076), decrease of negative emotions while watching TV (-18.5 % p = 0.011), during conversation without background noise (-16.5 % p = 0.0024), during conversation in noisy background (-17.1 % p = 0.027) and during conversation with several people (-20 % p = 0.014). The acceptability of the device was low to moderate.ConclusionTEO First® is an effective OTC hearing aid that improves the patient’s quality of life.Trial registrationCurrent Controlled Trials NCT01815788

The evaluation of hearing aid effect in presbycusis

Objective:To evaluate the effect of hearing aid in presbycusis. Method:Using the method of international outcome inventory for hearing aids(IOI-HA)and medium acoustic intensity(65 dBSPL) word recognition score(WRS), to evaluate the effect of hearing aid in moderate and severe presbycusis. Result:After the hearing aid of moderate presbycusis, The improved value of monosyllabic words and recognition rate in quite and noise statement(SNR=5) were 31.15%, 23.21%, 44.11%.However, improved values in severe presbycusis were 37.51%, 48.47%，50.17%, before and after hearing aid, the difference of the improved average value was statistically significant(P <0.05); Both the moderate and severe presbycusis were satisfacted with hearing aid.The IO-HA scores of moderate and severe presbycusis ranged from 15 to 34.The difference of IOIHA score of moderate and severe presbycusis had no statistical significance(P >0.05); moderate and severe presbycusis with high satisfaction with HA of quiet statement,and low satisfaction of monosyllabic words listening, and the degree of satisfaction was higher in patients with moderate to severe hearing loss in noise statement.Conclusion:Speech audiometry is an important method to assess the effect of hearing aid; IOI-HA is a timeconsuming short, subjective method.The combine of multiple evaluations have guiding significance to debugging of hearing aid expected effect and hearing aid device.

3D Games for Tuning and Learning About Hearing Aids

3D Games for Tuning and Learning About Hearing Aids

Noise generator for tinnitus treatment based on look-up tables

Treatment of tinnitus by means of masking sounds allows to obtain a significant improve of the quality of life of the individual that suffer that condition. In view of that, it is possible to develop noise synthesizers based on random number generators in digital signal processors (DSP), which are used in almost any digital hearing aid devices. DSP architecture have limitations to implement a pseudo random number generator, due to it, the noise statistics can be not as good as expectations. In this paper, a technique to generate additive white gaussian noise (AWGN) or other types of filtered noise using coefficients stored in program memory of the DSP is proposed. Also, an implementation of the technique is carried out on a dsPIC from Microchip®. Objective experiments and experimental measurements are performed to analyze the proposed technique.

Flexible pseudorandom number generator for tinnitus treatment implemented on a dsPIC

Treatment of tinnitus with masking sounds has reach a significant developed in recent years. It is mainly because it has been possible to implement noise sinthesizers based on random number generators in digital signal processors (DSP), which form a part of almost any digital hearing aid device. One limitation of these methods is that limitations of the DSP architecture prevent pseudo white noise of being generated conform to a real white noise statistics. In this paper, a technique to generate adittive white gaussian noise (AWGN) or noise with uniform distribution using coefficients stored in memory of the DSP program is proposed. An implementation of the technique is carried out on a dsPIC from Microchip and subjective experiments and experimental measurements are performed to validate the performance of the developed technique.

Audio signal's test in designing a cost-effective hearing aid device using a microcontroller

A large number of hearing impaired people in rural sector of Pakistan cannot afford the high prices of digital hearing aids. Moreover, since the analogue devices amplify the speech and noise signals equally, they are not much flexible and have functional limitations. These problems can be solved with digital devices which are generally costly. In this research work, a microcontroller based cost-effective and portable hearing aid is designed and tested. The main components include sound detection circuit, microcontroller and a digital to analogue (DAC) convertor. Device is aimed to process human voice frequencies with an adjustable gain of up to 80 dB. It is tested with an input audio signal and it showed satisfactory results for low frequency signals up to 3.5 kHz which caters for the frequency range of most human voices. The system is now being developed for more effective noise suppression and broader frequency range.

Evaluation of a Behind-the-Ear ECG Device for Smartphone Based Integrated Multiple Smart Sensor System in Health Applications

In this paper, we present a wireless Multiple Smart Sensor System (MSSS) in conjunction with a smartphone to enable an unobtrusive monitoring of electrocardiogram (ear-lead ECG) integrated with multiple sensor system which includes core body temperature and blood oxygen saturation (SpO2) for ambulatory patients. The proposed behind-the-ear device makes the system desirable to measure ECG data: technically less complex, physically attached to non-hair regions, hence more suitable for long term use, and user friendly as no need to undress the top garment. The proposed smart sensor device is similar to the hearing aid device and is wirelessly connected to a smartphone for physiological data transmission and displaying. This device not only gives access to the core temperature and ECG from the ear, but also the device can be controlled (removed and reapplied) by the patient at any time, thus increasing the usability of personal healthcare applications. A number of combination ECG electrodes, which are based on the area of the electrode and dry/non-dry nature of the surface of the electrodes are tested at various locations near behind the ear. The best ECG electrode is then chosen based on the Signal-to-Noise Ratio (SNR) of the measured ECG signals. These electrodes showed acceptable SNR ratio of ~20 db, which is comparable with existing tradition ECG electrodes. The developed ECG electrode systems is then integrated with commercially available PPG sensor (Amperor pulse oximeter) and core body temperature sensor (MLX90614) using a specialized micro controller (Arduino UNO) and the results monitored using a newly developed smartphone (android) application.