Canal Hearing Aid Research Articles

Bluetooth Coupling in Hearing Aids: Effect on Audiovisual Speech Recognition and Quality Rating of Compressed Speech in Older Individuals with Sloping Hearing Loss.

Introduction Older individuals often report that they find it difficulty in enjoying watching television since they find it hard to follow the rapid intensity variations, and voice changes from scene to scene. Objective The present study investigated the effect of coupling the hearing aid with the television via Bluetooth on audiovisual speech recognition and quality rating of compressed speech in older individuals with hearing loss. Method Twenty participants in the age range of 60 to 75 years who had moderate to moderately severe sloping sensorineural hearing loss were bilaterally fitted with digital receiver in the canal hearing aids. The hearing aid was coupled with a television via Bluetooth using a streamer. The video recorded stimuli were presented at 65 dB SPL at normal rate, 35% compression and 45% compression conditions. Speech recognition scores and quality ratings were obtained for each condition with and without the Bluetooth streamer connected to the hearing aids. Results Speech recognition scores were significantly better with Bluetooth coupling compared with conventional hearing aid use at 40% compressed speech rate. The quality was also rated higher in almost all parameters across speech rates when Bluetooth was used. Conclusions The improved clarity and nullification of room reverberation offered by Bluetooth coupling can potentially compensate for the age-related temporal processing deficit contributing to ease of listening.

The Frequency Characteristic of Silicone Domes in Receiver in the Canal Hearing Aids.

There are several types of silicone domes in receiver in the canal hearing aids (RICs), which have different occlusion levels. However, the frequency characteristics of each type of silicone dome are unclear. This study aimed to determine the frequency characteristics of three types of silicone domes (open domes, double-type power domes, and tulip domes) in RICs. This is an interventional study. In total, 11 participants with a normal sense of hearing were prospectively enrolled. Participants were fitted with hearing aids, which were adjusted to similar settings, and only the silicone domes were changed. The acoustic gain of hearing aids was adjusted to 20 dB in the range of 250 Hz to 4 kHz using the 2-cc coupler. We measured the real-ear aided gain (REAG) for each type of silicone dome. In each frequency, we statistically compared the REAG of each type of dome. Acoustic gain using the Open Fit coupler of each type of dome was also measured. The REAG was obtained with no leakage with open domes only at 2 kHz, and with tulip domes and double-type power domes in the range of 1 to 2 kHz. Double-type power domes obtained significantly higher REAG than tulip domes at 250 and 500 Hz. Under the Open Fit coupler, all types obtained higher acoustic gain than the REAG. This study provides the analysis of the frequency characteristics of silicone domes in RICs. The highest degree of occlusion was observed in double-type power domes, followed by tulip domes, and the lowest was observed in open domes.

Preferences for Hearing Aid Attributes Among People with Moderate or Greater Hearing Loss in Rural China: A Discrete Choice Experiment.

PurposeHearing loss has not received sufficient attention, especially in low- and middle-income countries where more than 80% of the people with hearing loss reside. Little is known about the preference for hearing aids among people with hearing loss in developing countries. The aim of this study is to elicit the preferences for hearing aid attributes among rural Chinese adults with moderate or greater hearing loss and examine how preferences vary across different individual socioeconomic characteristics.Patients and MethodsWe interviewed 125 adults in two rural counties in Shandong province in China. A discrete choice experiment (DCE) with eight attributes, comprising out-of-pocket (OOP) costs, hearing aid style, effective in quiet settings and noisy settings, feedback (whistling), connectivity, water/sweat resistance and battery life, were employed to examine participants’ preference for hearing aids. Mixed logit models were used for the statistical analyses.ResultsWhile OOP costs, effectiveness in quiet settings, water/sweat resistance and battery life were significantly associated with choosing a hearing aid, rural Chinese adults with moderate or greater hearing loss valued effectiveness in noisy settings above other attributes of hearing aids, followed closely by lack of feedback. The preference of the attributes of OOP costs, in the canal hearing aids, effectiveness in noisy settings, connectivity and battery life varied across individual socioeconomic characteristics including sex, marriage, employment, income and education level.ConclusionOur study supported the view that the development of noise suppression and feedback cancellation systems remained the main challenge for the hearing aid industry. Since OOP costs were also associated with choosing a hearing aid, the policy advice is to improve reimbursements from insurance schemes and/or reduce the costs of hearing aids.

Real ear measurement (REM) and auditory performances with open, tulip and double closed dome in patients using hearing aids.

The aim of the study is to evaluate the importance of acoustic modifications generated by different commercially available ear-tips, focused on domes of receiver in the canal hearing aids using Real Ear Measurement (REM). We enrolled 110 people selecting 200 ears bearers of hearing aids. In every patient, we performed REM and audiological tests with three different dome types: Open, Tulip and Double Closed (DC). Data about real-ear occluded gain (REOG), Pure Tone Average (PTA), Word Recognition Score (WRS) with aids switched on in Free Field, Ear and Auditory Comfort were collected and analyzed. REOG gain was statistically significant different between the three types of dome, with a DC that always closes the external auditory canal (EAC) (p < 0.001). There was no statistically significant difference between the PTA (p = 0.11). Regarding the WRS there were statistically significant differences between Open and DC dome (p < 0.001) and between Tulip and DC dome (p < 0.001), with worse discrimination when using DC. Both auditory and ear comfort are worse in the DC than in the other two domes (p < 0.001). From measured REOG gain values, in 135 cases Tulip dome does not occlude the EAC, with a statistically significant difference compared to DC (p < 0.001; Odd Ratio 0.0012; 95% CI 0.001-0.0196). Our study confirms the necessity to perform REM to evaluate if the prescription target is achieved, especially when tulip domes are used, because they may not occlude the ear canal, causing in some cases the reduction of the vocal discrimination.

The Effect of Digital Noise Reduction on Annoyance and Speech Perception in Low and High Acceptable Noise Level Groups.

Introduction Studies have reported that although speech perception in noise was unaltered with and without digital noise reduction (DNR), the annoyance toward noise measured by acceptable noise level (ANL) was significantly improved by DNR with the range between 2.5 and 4.5 dB. It is unclear whether a similar improvement would be observed in those individuals who have an ANL ≥ 14 dB (predictive of poor hearing aid user) often rejects their aid because of annoyance toward noise. Objectives (a) To determine the effect of activation of DNR on the improvement in the aided ANL from low- and high-ANL groups; and (b) to predict the change in ANL when DNR was activated. Method Ten bilateral mild to severe sloping sensorineural hearing loss (SNHL) participants in each of the low- and high-ANL groups were involved. These participants were bilaterally fitted with receiver in canal (RIC) hearing aids (Oticon, Smorum, Egedal, Denmark) with a DNR processor. Both SNR-50% (Signal to noise ratio (in dB) required to achieve 50 % speech recognition) and ANL were assessed in DNR-on and DNR-off listening conditions. Results Digital noise reduction has no effect on SNR-50 in each group. The annoyance level was significantly reduced in the DNR-on than DNR-off condition in the low-ANL group. In the high-ANL group, a strong negative correlation was observed between the ANL in DNR off and a change in ANL after DNR was employed in the hearing aid (benefit). The benefit of DNR on annoyance can be effectively predicted by baseline-aided ANL by linear regression. Conclusion Digital noise reduction reduced the annoyance level in the high-ANL group, and the amount of improvement was related to the baseline-aided ANL value.

Patient-oriented hearing aids: the specific features of approach and the results

Selection the type of hearing aid is one of the key elements of the hearing rehabilitation process, directly predetermining its efficacy. The authors suggest a method of selecting the type of hearing aid based on the patient’s needs —HASC (hearing aid selection criteria) questionnaire. The study compares the efficacy of the hearing aid when the type of the device is selected based on HASC data and when the correction was made with another type of hearing aid. When behind-the-ear hearing aids are used instead of the completely-in-canal aids (due to contraindications), which is preferable for the patient, it results in the decrease of service life, overall satisfaction with the device and its appearance, the increase in the number of re-adjustments. Selection of receiver-in-canal hearing aid instead of the completely-in-canal does not reduce its life time. Therefore, the receiver-in-canal hearing aids are an option in cases where there are contraindications to the use of completelyin- canal hearing aids without compromising the effectiveness. The use of the HASC method in audiology practice will improve the efficacy of electroacoustic correction and reduce the number of refuses to use the hearing aids.

Effectiveness of Low Cut Modified Amplification using Receiver in the Canal Hearing Aid in Individuals with Auditory Neuropathy Spectrum Disorder.

Introduction The studies on hearing aid benefit in individuals with auditory neuropathy spectrum disorder (ANSD) shows limited benefit. Low cut modified amplification is found to be effective in few individuals with ANSD. With advancement in technology, receiver in the canal (RIC) hearing aids have proven to be more effective than traditional behind the ear (BTE) hearing aids. Objective Thus, the present study attempts to determine the effectiveness of low cut modified amplification using RIC and BTE. Method Twenty participants with ANSD were fitted with BTE and RIC using traditional and low cut modified amplification. We divided them into good and poor performers based on unaided speech identification scores (SIS). We then compared aided SIS and aided benefit across conditions in good and poor performers with ANSD across both conditions using BTE and RIC. Results The results of the study showed that the aided performance improved with low cut modified amplification in both BTE and RIC hearing aids. The improvement noticed with low-cut modified fitting with RIC was significant in more than BTE, especially in good performers with ANSD. Conclusion The improved clarity and naturalness of sound with RIC may have led to better aided scores and better acceptance of the hearing aid. Thus, low-cut modified amplification, preferably with RIC, needs to be attempted in fitting individuals with ANSD, especially in those with good unaided SIS in quiet.

Comparative Analyses between Receiver in the Canal Hearing Aids and Closed Fit Hearing Aids: Preliminary Study

Received August 19, 2014 Revised October 7, 2014 Accepted October 23, 2014 Address for correspondence Jeong Hun Jang, MD Department of OtorhinolaryngologyHead and Neck Surgery, School of Medicine, Kyungpook National University, 130 Dongdeok-ro, Jung-gu, Daegu 700-721, Korea Tel +82-53-420-5781 Fax +82-53-423-4524 E-mail jangjh@knu.ac.kr Background and ObjectivesZZThe aim of this study was to compare the degree of satisfaction of the patients, hearing loss type and severity, and satisfactory and unsatisfactory factors between closed fit hearing aid (HA) and receiver in the canal (RIC) HA. Subjects and MethodZZSeventeen patients with hearing loss participated in this study. All patients had used closed fit HAs prior to the study, with the ratio of those using in the canal (ITC) types and completely in the canal (CIC) types being 4:13. After a 2-week trial period of using RIC HAs, patients were evaluated for their satisfaction of using RIC HAs by filling out the questionnaire on the Korean version International Outcome Inventory for hearing aids (K-IOI-HA). ResultsZZThe visual analogue scale (VAS) score of closed fit HA was higher in the RIC-HAdissatisfied group (≤5, n=8) than in the RIC-HA-satisfied group (>5, n=9). The K-IOI-HA score of closed fit HA was higher than that of RIC HA in the RIC-HA-dissatisfied group and similar in the RIC-HA-satisfied group. Audiologically, air conduction and bone conduction thresholds at 500 Hz were lower in the RIC-HA-satisfied group than in the RIC-HA-dissatisfied group. In addition, the VAS score of RIC HA was negatively correlated with air and bone conduction thresholds and the K-IOI-HA score of RIC HA was positively correlated with speech discrimination score, whereas the VAS and K-IOI-HA scores of closed fit HA were not. ConclusionZZAmong the patients with closed fit HA, some patients indicated RIC HA to be suitable and showed intention to change. The HA should be prescribed firstly based on audiologic criteria, which could increase the subjective satisfaction and prevent poor compliance due to incongruity. Korean J Otorhinolaryngol-Head Neck Surg 2015;58(4):249-56

Embedding Active and Passive Devices in Medical Electronics

Efforts to increase the packaging efficiency of microelectronic systems have been extensive and continuous over the past few decades. Evidence of this can be seen even before the expansion of the space program by the United States in 1961 and the race to the moon; one of the first settings where size was truly limited and miniaturization of electronics was a necessity. In the 1950's the world saw its first major size reduction of electronic component with the phase out of the vacuum tube in favor of the transistor. The transistor saw its first major commercial use in 1952 via hybrid vacuum tube transistor technology. While many industries benefitted from the shift, in 1954 the hearing aid industry specifically experienced major improvements owing to the implementation of transistors, becoming smaller, requiring less power and having better functionality. The first 4-transistor AM radio product followed shortly thereafter. Much of today's effort since 1978 has been driven by the telecommunications industry that has succeeded in reducing cell phone size while simultaneously increasing functionality. Just as in the 1950's, hearing aid technology continues to be at the forefront when it comes to miniaturization. The hearing aid business has always had the need to use extremely small electronic packaging. The first completely in the canal (CIC) hearing aids were produced in 1993 and required all electronic components to be small enough that they fit entirely inside the ear canal. The introduction of wireless systems into hearing aids has sharply increased component count. Due to the size and shape of a multitude of types of hearing aids, flexible circuits need to be folded and bent to fit inside hearing aid cases, with essentially all available space being used. More powerful processors and more memory are enabling sophisticated algorithms that are able to greatly improve sound quality. There is also a strong market desire to add more features to hearing products while at the same time making them smaller and less visible. The latest hearing aids have succeeded in the later demand, constructed so small they are not visible and consequently are called invisible in the canal (IIC). In order to continue meeting the markets want for smaller and more features, a new packaging method needed to be developed. One such option is embedded die packaging. This paper will examine the use of embedded die packaging (or chip-in-flex) to drive significant further size reduction in custom and standard hearing instruments over what can be achieved using chip-on-flex or traditional ceramic hybrid based technologies. The historical drivers, available circuit board technologies, use of integrated passive devices, performance improvement, size reduction, device reliability, changes in supply chain, impact on wafer test, impact on device test, and challenges of working with wafers instead of die will be discussed.

An Acoustical Assessment of the Music Memory in Commercially Available Hearing Aids

Hearing aids amplify speech-input signals using nonlinear amplification (i.e., wide dynamic range compression). When WDRC is used to process a music-input signal, listener’s report a negative aided listening experience. To circumvent this negative experience, hearing aids allow for music-input stimuli to be processed using a modified frequency-gain response, known as a memory or program. The music memory, in general, processes the input signal using a linear-like frequency-gain response, elevated output, or both. Increasing gain and output, we conjecture, has the potential to place the wearer at-risk (i.e., ≥85 Leq dBA) for Hearing-aid-induced hearing loss (HAIHL). We assessed the potential of this risk in two experiments. In Experiment I, 2-cc coupler gain was determined in three commercially available receiver-in-the ear/receiver-in-the-canal (RITE/RIC) hearing aids. Coupler gain responses were determined for a composite signal presented at 65 and 100 dB SPL for the WDRC memory and music memory, and for different degrees of occlusion. Results from this experiment were reported qualitatively. In Experiment II, the same three devices were fit on an acoustical manikin. Recordings of 10 musical passages were obtained for the same two memories, adjusted for the degree of occlusion at three presentation levels (i.e., 85-, 94-, and 103-dB SPL). Analyses of the recordings revealed that two devices programed in the music mode exceeded the at-risk threshold at presentation levels of 94- and 103-dB SPL. In addition, the same two devices programmed in WDRC exceeded the at-risk threshold at a presentation level of 103-dB SPL. Implications and future directions are discussed.

CANAL HEARING DEVICE WITH DISPOSABLE BATTERY MODULE

A modular canal hearing aid assembly having a main module positioned in the ear canal and a disposable battery module laterally positioned in the ear canal. The main module incorporates the durable components of a hearing device including the receiver, microphone and electronics. The disposable battery module comprises consumable elements including battery and incoming sound port. The disposable battery module provides a unitary structure that is easier to handle, remove from the main module, and replace when any of the consumable elements is depleted or degraded. The canal hearing device assembly is generic in shape and provided with assorted seal tips for "instant fitting" without resorting to custom manufacturing.

Concha/open canal hearing aid apparatus and method

An improved hearing aid and method that employs a combination microphone/speaker, sized to have the microphone inserted within the concha bowl of the outer ear and the speaker is inserted within which the opening of the ear canal such that it does not obstruct the same for more natural hearing.

Pilot study on the effectiveness of the conventional CROS, the transcranial CROS and the BAHA transcranial CROS in adults with unilateral inner ear deafness

The objective of the present pilot study is to evaluate the effectiveness of three conventional contralateral routing of sound (CROS) hearing aids in adults with unilateral inner ear deafness. The study included tertiary referral center. Ten patients with unilateral inner ear deafness and normal hearing in the contralateral ear were selected to evaluate three different methods of amplification: the CROS hearing aid, the completely in the canal hearing aid and the bone-anchored hearing aid CROS (BAHA). Each of the three hearing aids was tried in a random order for a period of 8 weeks. Audiometric performance, including speech-in-noise, directional hearing and subjective benefit were measured after each trial period, using the APHAB, SSQ and single-sided deafness questionnaire. Sound localization performance was essentially at chance level in all four conditions. Mixed results were seen on the other patient outcome measures that alternated in favor of one of the three CROS devices. After the trial, three patients chose to be fitted with the BAHA CROS and one with the conventional CROS. In conclusion, most of the patients experienced some degree of benefit with each of the three hearing aids. Preference for one of the three hearing aids was independent of the order in which they were tried. It would be worthwhile to formulate selection criteria; still, we recommend that all patients with unilateral inner ear deafness should be offered a trial with at least the BAHA CROS.

Binaural hearing abilities of bilaterally fitted hearing aid users assessed using objective and subjective outcome measures

Aided spatial hearing in the hearing impaired remains a rather sparsely explored topic. Therefore we do not know enough about the ability of the hearing impaired to exploit auditory cues for spatial hearing. In an attempt to advance our knowledge the following experiment was set up. A group of 21 experienced hearing aid users took part in a test using modern completely in the canal hearing aids in the field for at least 7 weeks. After acclimatization to the devices they were tested on a number of outcome measures. These included spatial unmasking, an interview administered selection of questions from the Speech Spatial and Qualities of hearing scale, and a baseline speech in noise measure. Spatial unmasking was assessed using three concurrent female talkers, with the target talker always presented directly ahead and the maskers presented either at +/- 50 degrees or both at 180 degrees. This presentation will provide results from the study described above along with possible relations to auditory and non-auditory predictors of spatial hearing performance.

A comparative study of the audiological outcomes with Retro-X (semi-implantable hearing aid system) and conventional open fitting hearing aids

The objective of this study was to compare the results of hearing augmentation with the Retro-X semi-implantable hearing aid to a conventional non-implantable open canal hearing aid using the same software technology (Titan-X, auric Hearing Systems, HiKaNo.:13.20.03.0047). Nineteen subjects (20 ears) with mild to moderate high-frequency sensory-neural hearing loss were included in this clinical study. All the subjects were first fitted with a conventional open canal hearing aid (Titan-X). After a period of 4-6 weeks audiological evaluations were performed using standardized speech tests in quiet and noise. Subjective evaluation was performed with the help of standardized questionnaires. After this phase the patients received the semi-implantable Retro-X device under local anaesthesia and 4 weeks later were fitted with a hearing module with the same software technology as the conventional Titan-X hearing aid. Four weeks following the first fitting the same audiological evaluations were performed under similar conditions and the patients were evaluated again using the same questionnaires in order to compare the results of the Retro-X semi-implantable system with the conventional open canal hearing aid. Audiological evaluations revealed better results with the semi-implantable Retro-X in the adaptive speech in noise test; however, the results of the monosyllabic word test in quiet were similar for the Retro-X and conventional open canal hearing aid. The patients subjectively preferred the improved wearing comfort of the semi-implantable device. The Retro-X semi-implantable hearing aid provides better speech perception in noise and higher wearing comfort in comparison to the conventional open canal hearing aids. Considering the simple implantation procedure under local anaesthesia with low complication rate, Retro-X is an alternative to the conventional open canal hearing aids in patients with mild to moderate high frequency sensory-neural hearing loss.

Stick It in Your Ear: A Systematic Approach to Earmold Selection

Stick It in Your Ear: A Systematic Approach to Earmold Selection

Simultaneous use of soundbridge implantable hearing device and conventional hearing aid

Objectives: The Vibrant Symphonix Soundbridge (VSB) middle ear hearing implant has proven to be an effective alternate treatment modality for patients with mild to moderate sensorineural hearing loss. The purpose of this study was to evaluate the audiologic performance of patients wearing the Soundbridge and a conventional hearing aid simultaneously in the same ear. This study was prompted by several Soundbridge patient reports that they obtained improved hearing with simultaneous use. Methods: Two patients who were audiologically marginal Soundbridge implant candidates reported marginal performance with their implants after surgery. These patients reported significant improvement with simultaneous use of a canal hearing aid and the Soundbridge. A full audiologic battery and subjective questionnaire was performed on these patients. Results: Both patients reported a significant subjective improvement in performance using both devices. Word discrimination score was significantly improved when both devices were worn. Conclusion: This is the first report of simultaneous use of an implantable hearing device and conventional hearing aid. This technique may be offered to patients who may be marginal candidates for either device separately and may be a benefit as an alternative to cochlear implantation.

Open ear canal hearing aid system

An open ear canal hearing aid system (1) comprises an ear canal tube (10) sized or shaped for positioning in an ear canal of a user so that the ear canal is at least partially open for directly receiving ambient sounds. The open ear canal hearing aid system (1) further comprises a sound processor (44, 46) for amplifying received ambient sounds included within a predetermined frequency to produce processed sounds and a receiver (50) for supplying said processed sounds to said ear canal tube.

Ear canal microphone

An open ear canal hearing aid system is disclosed which comprises a plurality of ear canal tubes sized for positioning in an ear canal of a user so that the ear canal is at least partially open for directly receiving ambient sounds. The open ear canal hearing aid system further comprises a sound processor for amplifying ambient sounds received through one of the ear canal tubes within a predetermined frequency range and to produce processed sounds and for supplying the processed sounds to the second ear canal tube. According to other embodiments of the present invention, the speaker and/or microphone can be located in the ear canal at the end of the ear canal tubes. In these embodiments, the speaker and/or microphone are electrically connected to the sound processor by wires in the ear canal tubes.

Variations in the feedback of hearing aids.

Variations in the loop response of hearing aids caused by jaw movements, variations in acoustics outside the ear, and variations of vent size have been identified. Behind The Ear (BTE) and In The Ear Canal (ITEC) hearing aids were considered. The largest variations among the variations of the acoustics outside the ear, except when the hearing aid was partly removed, were found with the ITEC when a telephone set was placed by the ear. The variations of the loop response caused by changes in vent size were compared with the variations of a theoretical model of the feedback path. The theoretical model was also used to compare the feedback of different designs of the vent that gives the same acoustic impedance at low frequencies. The calculated feedback was less with the short vents (12 mm) than the long vents (24 mm).