Conventional Hearing Aids Research Articles

An evaluation of the performance of two binaural beamformers in complex and dynamic multitalker environments

Objective: Binaural beamformers are super-directional hearing aids created by combining microphone outputs from each side of the head. While they offer substantial improvements in SNR over conventional directional hearing aids, the benefits (and possible limitations) of these devices in realistic, complex listening situations have not yet been fully explored. In this study we evaluated the performance of two experimental binaural beamformers. Design: Testing was carried out using a horizontal loudspeaker array. Background noise was created using recorded conversations. Performance measures included speech intelligibility, localization in noise, acceptable noise level, subjective ratings, and a novel dynamic speech intelligibility measure. Study sample: Participants were 27 listeners with bilateral hearing loss, fitted with BTE prototypes that could be switched between conventional directional or binaural beamformer microphone modes. Results: Relative to the conventional directional microphones, both binaural beamformer modes were generally superior for tasks involving fixed frontal targets, but not always for situations involving dynamic target locations. Conclusions: Binaural beamformers show promise for enhancing listening in complex situations when the location of the source of interest is predictable.

A Practical Tablet-Based Hearing Aid Configuration as an Exemplar Project for Students of Instrumentation.

This paper presents the configuration and digital signal processing details of a tablet-based hearing aid transmitting wirelessly to standard earphones, whereby the tablet performs full sound processing rather than solely providing a means of setting adjustment by streaming to conventional digital hearing aids. The presented device confirms the recognized advantages of this tablet-based approach (e.g., in relation to cost, frequency domain processing, amplification range, versatility of functionality, component battery rechargeability), and flags the future wider-spread availability of such hearing solutions within mainstream healthcare. The use of a relatively high sampling frequency was found to be beneficial for device performance, while the use of optional off-the-shelf add-on components (e.g., data acquisition device, high fidelity microphone, compact wireless transmitter/receiver, wired headphones) are also discussed in relation to performance optimization. The easy-to-follow configuration utilized is well suited to student learning/research instrumentation projects within the health and biomedical sciences. In this latter regard, the presented device was pedagogically integrated into a flipped classroom approach for the teaching of bioinstrumentation within an Allied Health Sciences School, with the subsequent establishment of positive student engagement outcomes.

Symptoms of Psychopathology in Hearing-Impaired Children.

Objectives:Children with hearing loss are at risk of developing psychopathology, which has detrimental consequences for academic and psychosocial functioning later in life. Yet, the causes of the extensive variability in outcomes are not fully understood. Therefore, the authors wanted to objectify symptoms of psychopathology in children with cochlear implants or hearing aids, and in normally hearing peers, and to identify various risk and protective factors.Design:The large sample (mean age = 11.8 years) included three subgroups with comparable age, gender, socioeconomic status, and nonverbal intelligence: 57 with cochlear implants, 75 with conventional hearing aids, and 129 children who were normally hearing. Psychopathology was assessed by means of self- and parent-report measures.Results:Children with cochlear implants showed similar levels of symptoms of psychopathology when compared with their normally hearing peers, but children with hearing aids had significantly higher levels of psychopathological symptoms, while their hearing losses were approximately 43 dB lower than those of children with implants. Type of device was related with internalizing symptoms but not with externalizing symptoms. Furthermore, lower age and sufficient language and communication skills predicted less psychopathological symptoms.Conclusions:Children who are deaf or profoundly hearing impaired and have cochlear implants have lower levels of psychopathological symptoms than children with moderate or severe hearing loss who have hearing aids. Most likely, it is not the type of hearing device but rather the intensity of the rehabilitation program that can account for this difference. This outcome has major consequences for the next generation of children with hearing loss because children with profound hearing impairment still have the potential to have levels of psychopathology that are comparable to children who are normally hearing.

The Effect of a High Upper Input Limiting Level on Word Recognition in Noise, Sound Quality Preferences, and Subjective Ratings of Real-World Performance.

One important factor that plays a role in front-end processing is the analog-to-digital converter within current hearing aids. The average input dynamic range of hearing aids is 96 dB SPL with an upper input limiting level (UILL) of 95-105 dB SPL. The UILL of standard hearing aids could distort loud signals, such as loud speech or music, which have root-mean-square values of 90 and 105 dB SPL with crest factors of 12 dB SPL to 14-20 dB SPL, respectively. This indicates that these loud sounds could create a distorted signal for patients when the input limiting level is reached. To examine if significant differences in word recognition in noise, sound quality preferences, and subjective ratings of real-world performance exist between conventional and high UILL hearing aids. Words in noise and sound quality preferences were assessed using recordings on a Knowles Electronic Manikin for Acoustic Research with conventional and high UILL hearing aids, different microphone modes, and listening conditions. Participants wore the hearing aids for 2 mo and completed questionnaires on subjective performance. Ten adults with bilateral slight to moderately severe sensorineural hearing loss were recruited. A four-factor repeated-measures analysis of variance (ANOVA) revealed significant differences between the conventional and high UILL across microphone modes and listening conditions for words in noise [F(2, 18) = 6.0; p < 0.05]. A three-factor repeated-measures ANOVA for sound quality preferences revealed a significant difference only for presentation level [F(1, 9) = 81.0; p < 0.001]. A one-factor ANOVA did not reveal significant differences between the conventional and high UILL on subjective ratings of real-world performance. Word recognition and sound quality preferences revealed significant differences between the conventional and high UILL; however, there were no differences in subjective ratings of real-world performance. One participant preferred the conventional UILL, two the high UILL, and seven thought performance was equal, which may be due to the listening environments participants encountered, as evidenced by datalogging.

Ear malformations, hearing loss and hearing rehabilitation in children with Treacher Collins syndrome

ObjectiveThe aim of this study was to assess the main ear malformations, hearing loss and auditory rehabilitation in children with Treacher Collins syndrome. MethodsWe performed a retrospective study of 9 children with Treacher Collins syndrome treated in a central hospital between January 2003 and January 2013. ResultsThis study showed a high incidence of malformations of the outer and middle ear, such as microtia, atresia or stenosis of the external auditory canal, hypoplastic middle ear cavity, dysmorphic or missing ossicular chain. Most patients had bilateral hearing loss of moderate or high degree. In the individuals studied, there was functional improvement in patients with bone-anchored hearing aids in relation to conventional hearing aids by bone conduction. ConclusionsTreacher Collins syndrome is characterized by bilateral malformations of the outer and middle ear. Hearing rehabilitation in these children is of utmost importance, and bone-anchored hearing aids is the method of choice.

Low empathy in deaf and hard of hearing (pre)adolescents compared to normal hearing controls.

ObjectiveThe purpose of this study was to examine the level of empathy in deaf and hard of hearing (pre)adolescents compared to normal hearing controls and to define the influence of language and various hearing loss characteristics on the development of empathy.MethodsThe study group (mean age 11.9 years) consisted of 122 deaf and hard of hearing children (52 children with cochlear implants and 70 children with conventional hearing aids) and 162 normal hearing children. The two groups were compared using self-reports, a parent-report and observation tasks to rate the children’s level of empathy, their attendance to others’ emotions, emotion recognition, and supportive behavior.ResultsDeaf and hard of hearing children reported lower levels of cognitive empathy and prosocial motivation than normal hearing children, regardless of their type of hearing device. The level of emotion recognition was equal in both groups. During observations, deaf and hard of hearing children showed more attention to the emotion evoking events but less supportive behavior compared to their normal hearing peers. Deaf and hard of hearing children attending mainstream education or using oral language show higher levels of cognitive empathy and prosocial motivation than deaf and hard of hearing children who use sign (supported) language or attend special education. However, they are still outperformed by normal hearing children.ConclusionsDeaf and hard of hearing children, especially those in special education, show lower levels of empathy than normal hearing children, which can have consequences for initiating and maintaining relationships.

A Case of Incus Vibroplasty: Postoperative Changes in Residual Hearing.

In patients with mild to severe hearing loss, conventional hearing aids offer limited benefits and several problems with feedback and cosmesis. Middle ear implants are a feasible option for patients with moderate to severe hearing loss who are unable to achieve adequate benefit from or cannot tolerate hearing aids for various reasons. Here we present a case of middle ear implant surgery using Vibrant Soundbridge with incus vibroplasty technique, and describe the hearing changes during postoperative follow-up.

Prediction of the use of conventional hearing aids in Korean adults with unilateral hearing impairment

Objective: To determine the use of a hearing aid at six months post-fitting and to evaluate the predictors of its ongoing use in Korean adults with unilateral hearing impairment (HI). Design: Retrospective study at a secondary referral hospital over a 15-year period. Study sample: This study analysed 119 adults with unilateral HI who had been recommended for hearing amplification (55 men and 64 women, mean age, 58.0 ± 11.7 years). Six months after the fitting, all of the participants were surveyed regarding subsequent decisions and actions about obtaining hearing aids. Results: General uptake rate for a hearing aid was 68.1% (58.0% of participants surveyed were successful users, and 10.1% were intermittent users). The most significant parameter associated with hearing-aid use was social and/or work activities (R2 = 0.457), and the significant predictors for successful hearing-aid use were social and/or work activities and method of signal processing (discriminatory power = 56.3%). Conclusions: Six months post-fitting, 68.1% of Korean adults with unilateral HI who had agreed to try a hearing aid continued to use it regularly. The predictors for hearing-aid use six months post-fitting included social and/or work activities and digital signal processing.

Treatment of Menière’s Disease

Diagnosis of Menière's disease is made with a characteristic patient history, including discrete episodes of vertigo lasting 20min or longer, accompanied by sensorineural hearing loss, which is typically low frequency at first, aural fullness, and tinnitus. Workup includes audiometry, a contrast enhanced MRI of the internal auditory canals, and exclusion of other diseases that can produce similar symptoms, like otosyphilis, autoimmune inner ear disease, perilymphatic fistula, superior semicircular canal syndrome, Lyme disease, multiple sclerosis, vestibular paroxysmia, and temporal bone tumors. A history of migraine should be sought as well because of a high rate of co-occurrence (Rauch, Otolaryngol Clin North Am 43:1011-1017, 2010). Treatment begins with conservative measures, including low salt diet, avoidance of stress and caffeine, and sleep hygiene. Medical therapy with a diuretic is the usual next step. If that fails to control symptoms, then the options of intratympanic (IT) steroids and betahistine are discussed. Next tier treatments include the Meniett device and endolymphatic sac surgery, but the efficacy of both is controversial. If the above measures fail to provide symptomatic control of vertigo, then ablative therapies like intratympanic gentamicin are considered. Rarely, vestibular nerve section or labyrinthectomy is considered for a patient with severe symptoms who does not show a reduction in vestibular function with gentamicin. Benzodiazepines and anti-emetics are used for symptomatic control during vertigo episodes. Rehabilitative options for unilateral vestibular weakness include physical therapy and for unilateral hearing loss include conventional hearing aids, contralateral routing of sound (CROS) and osseointegrated hearing aids.

The father of Osseointegration and the godfather of the BAHA: Professor Per-Ingvar Brånemark, Göteborg Sweden has passed away in his 86th year

Branemark got his medical training at University of Lund where he studied rheology in the living bone of the rabbit. During these studies he noted bone fragments on the surface of his titanium implant, in those days a metal not commonly used in medicine. This capacity of serendipity opened the way for modern implantology. He coined the finding osseointegration, a term today well known especially amongst otolaryngologists [1]. In 1960, he moved to University of Goteborg. He got numerous awards and been honorary doctorates at 29 universities. He guided more than 40 Ph.D. students to dissertations. The first clinical application of osseointegration was dental implants in the edentulous jaw [2]. Today this is considered as the golden standard for bone-anchored dentures and millions of patients all over the world have benefitted from his pioneering work. Branemark tried to find an acoustic way to evaluate implant stability. This became one of the starting points for hearing through direct bone conduction. Patients hard of hearing cannot always be helped with surgical reconstruction and some cannot use a conventional hearing aid. Chronic ear disease and congenital malformations are two reasons for this. Branemark suggested placing titanium implant in the bone behind the ear and after healing an impedance-matched transducer was attached to the implant. This work was made in close cooperation between him, the Department of Otolaryngology at Sahlgrenska University Hospital in Goteborg and Chalmers University of Technology also in Goteborg. Bo Hakansson, now professor at Chalmers, was the innovator of the new transducer that since then has been refined and become smaller and yet more effective [3, 4]. In 2005, Cochlear BAS was created and RD some did not even go out in daylight hours. Using the same implants as for the BAHA the patients got implants for retention for facial prostheses made of Silicon. The technical and artistically development was made by anaplastologist Kerstin Bergstrom at our Implant Unit. Branemark took an eager interest in this work, and especially in major defect, he was often the leading A. Tjellstrom (&) Department of Otolaryngology, Sahlgrenska Academy, University of Goteborg, Gothenburg, Sweden e-mail: anders.tjellstrom@orlss.gu.se

High-Frequency Audibility: The Effects of Audiometric Configuration, Stimulus Type, and Device

For the last decade, the importance of providing amplification up to 9-10 kHz has been supported by multiple studies involving children and adults. The extent to which a listener with hearing loss can benefit from bandwidth expansion is dependent on the audibility of high-frequency cues. The American National Standards Institute (ANSI) devised a standard method for measuring and reporting hearing aid bandwidth for quality-control purposes. However, ANSI bandwidth measurements were never intended to reflect the true frequency range that is audible for a speech stimulus for a person with hearing loss. The purpose of this study was to (1) determine the maximum audible frequency of conventional hearing aids using a speech signal as the input through the hearing aid microphone for different degrees of hearing loss, (2) examine how the maximum audible frequency changes when the input stimulus is presented through hearing assistance technology (HAT) systems with cross-coupling of manufacturers' transmitters and receivers, and (3) evaluate how the maximum audible frequency compares with the upper limit of the ANSI bandwidth measure. Eight behind-the-ear hearing aids from five hearing aid manufacturers were selected based on a range of ANSI bandwidth upper frequency limits. Three audiometric configurations with varied degrees of high-frequency hearing loss were programmed into each hearing aid. Hearing aid responses were measured with the International Speech Test Signal (ISTS), broadband noise, and a short speech token (/asa/) as stimuli presented through a loudspeaker. HAT devices from three manufacturers were used to create five HAT scenarios. These instruments were coupled to the hearing aid programmed for the audiogram that provided the highest maximum audible frequency in the hearing aid analysis. The response from each HAT scenario was obtained using the same three stimuli as during the hearing aid analysis. All measurements were collected in an audiometric sound booth on a Knowles Electronic Manikin for Acoustic Research (KEMAR). A custom computer program was used to record responses from KEMAR. Maximum audible frequency was defined as the highest point where the Long-Term Average Speech Spectrum (LTASS) intersected the audiogram. The average maximum audible frequency measured through KEMAR ranged from 3.5 kHz to beyond 8 kHz and varied significantly across devices, audiograms, and stimuli. The specified upper limit of the ANSI bandwidth was not predictive of the maximum audible frequency across conditions. For most HAT systems, the maximum audible frequency for the hearing aid plus HAT condition was equivalent to the hearing aid for the same measurement configuration. In some cases, however, the HAT system imposed a lower maximum audible frequency than the hearing aid-only condition. The maximum audible frequency of behind-the-ear hearing aids is dependent on the degree of hearing loss, amplification device, and stimulus input. Estimating the maximum audible frequency by estimating the frequency where the speech spectrum intersects the audiogram in the high frequencies can assist clinicians in making decisions about which device or configuration of devices provides the greatest access to high-frequency information, as well as whether frequency-lowering technology should be used.

VIBRANT SOUNDBRIDGE&lt;sup&gt;®&lt;/sup&gt; 国内臨床治験の有効性と安全性の評価

Middle ear implants (MEIs) such as the Vibrant Soundbridge (VSB) are attractive and alternative treatments for patients with conductive, sensorineural, and mixed hearing loss who do not benefit from, or who choose not to wear, conventional hearing aids (HAs). Recent studies suggest that MEIs can provide better improvements in functional gain, speech perception, and quality of life than HAs, although there are certain risks associated with the surgery which should be taken into consideration, including facial nerve or chorda tympanic nerve damage, dysfunctions of the middle and inner ears, and future device failure/explantation. In Japan, a multi-center clinical trial of VSB was conducted between 2011-2014. A round window vibroplasty via the transmastoid approach was adopted in the protocol. The bony lip overhanging the round window membrane (RWM) was extensively but very carefully drilled to introduce the Floating Mass Transducer (FMT). Perichondrium sheets were used to stabilize the FMT onto the RWM. According to the audiological criteria, the upper limit of bone conduction should be 45 dB, 50 dB, and 65 dB from 500 Hz to 4, 000 Hz. Twenty-five patients underwent the surgery so far at 13 different medical centers. The age at the surgery was between 26-79 years old, and there were 15 males and 10 females. The cause of conductive or mixed hearing loss was middle ear diseases in 23 cases and congenital aural atresia in two cases. The data concerning on the effectiveness and safety of VSB was collected before the surgery and 20 weeks after the surgery. Significant improvements of free-field Pure Tone Audiogram (PTA) from 250 Hz to 8, 000 Hz were confirmed (p < 0.001). Hearing gain up to 40 dB was achieved in the 1, 000 Hz to 4, 000 Hz range. No deterioration in either air conduction or bone conduction at PTA was noted at 20 weeks after the surgery. Monosyllable speech perception in both quiet and noisy conditions improved significantly (p < 0.001). The speech discrimination score in both quiet and noisy conditions improved significantly too (p < 0.001). In the future, it is likely that there will be an increasing population even in Japan that will meet the criteria for MEIs such as VSB. However, the long-term efficacy and safety of these devices should be established.

Outcomes after Bonebridge Implantation: Audiological Benefits and Health Related Quality of Life

Objective: Bone conduction implants (BCI) are medical devices for conductive and mixed hearing losses as well as for single side sensorineural deafness (SSD). All direct-drive BCI transmit vibrations directly to the skull bone and can be divided into percutaneous and active transcutaneous devices. Method: We report a case series of 10 patients, suffered from mixed or conductive hearing loss, submitted to Bonebridge implantation. Audiological evaluation was conducted at six months to observe the functional impact of this device. Patients were asked to answer the Glasgow Benefit Inventory (GBI), a retrospective questionnaire, to measure the effect of the surgical intervention on the health-related quality of life. Results: The functional gain was found to range from 25 dB to 40 dB. Speech perception in noise improves in all patients and no post-operative complications were observed. GBI questionnaire has reflected high device satisfaction rate. Conclusion: Active transcutaneous BCI represent an effective and safety solution for people that cannot have adequate benefit from conventional hearing aids, to restore good audiological performance and life satisfaction.

人工聴覚機器の現状

Remarkable advances have been made in the field of cochlear implantation, especially the new trends of hearing and structure preservation. Electric acoustic stimulation (EAS) is becoming a standard procedure worldwide and has improved the quality of life of patients with a ski-slope type audiogram, while Vibrant Soundbridge (VSB) and Bone Conductive Implant are also becoming available as hearing implants for the hearing-impaired population. We present the current information about hearing implants in Japan. Advances in the development of new atraumatic concepts of electrode design as well as in surgical techniques have enabled structure preservation after cochlear implantation, and EAS is a new trend for patients with residual hearing at lower frequencies, that became eligible for coverage by the national health insurance in Japan in 2014. The VSB is an active middle ear implant that was developed for the treatment of sensorineural hearing loss. Stimulation of the cochlea by coupling the small electromagnetic element called the floating mass transducer (FMT) to the round window membrane was a promising second alternative for the treatment of conductive or mixed hearing loss. A multicenter clinical study for VSB with a round window approach was conducted in Japan in 2014. Bone conductive implants allow direct transmission to the bone of the skull, and Baha is a semi-implantable percutaneous BC hearing device. A multicenter clinical study with 9 participant institutions was conducted in Japan between 2006 and 2009 to compare the efficacy of Baha with that of conventional hearing aids. Baha became eligible for coverage by the national health insurance in 2013. Several types of bone conductive implants have been developed and may be used in Japan in the near future.

Paired comparisons of nonlinear frequency compression, extended bandwidth, and restricted bandwidth hearing aid processing for children and adults with hearing loss.

Preference for speech and music processed with nonlinear frequency compression (NFC) and two controls (restricted bandwidth [RBW] and extended bandwidth [EBW] hearing aid processing) was examined in adults and children with hearing loss. The purpose of this study was to determine if stimulus type (music, sentences), age (children, adults), and degree of hearing loss influence listener preference for NFC, RBW, and EBW. Design was a within-participant, quasi-experimental study. Using a round-robin procedure, participants listened to amplified stimuli that were (1) frequency lowered using NFC, (2) low-pass filtered at 5 kHz to simulate the RBW of conventional hearing aid processing, or (3) low-pass filtered at 11 kHz to simulate EBW amplification. The examiner and participants were blinded to the type of processing. Using a two-alternative forced-choice task, participants selected the preferred music or sentence passage. Participants included 16 children (ages 8-16 yr) and 16 adults (ages 19-65 yr) with mild to severe sensorineural hearing loss. All participants listened to speech and music processed using a hearing aid simulator fit to the Desired Sensation Level algorithm v5.0a. Children and adults did not differ in their preferences. For speech, participants preferred EBW to both NFC and RBW. Participants also preferred NFC to RBW. Preference was not related to the degree of hearing loss. For music, listeners did not show a preference. However, participants with greater hearing loss preferred NFC to RBW more than participants with less hearing loss. Conversely, participants with greater hearing loss were less likely to prefer EBW to RBW. Both age groups preferred access to high-frequency sounds, as demonstrated by their preference for either the EBW or NFC conditions over the RBW condition. Preference for EBW can be limited for those with greater degrees of hearing loss, but participants with greater hearing loss may be more likely to prefer NFC. Further investigation using participants with more severe hearing loss may be warranted.

Osseointegration and its role in management of hearing loss

Osseointegration is a biological process by which a structural connection is created between living bone and the surface of a load-carrying implant. This phenomenon has been used in a range of medical interventions. In 1977, Tjellstrom reported on osseointegrated bone-anchored hearing device as an alternative to conventional bone-conducting hearing aids, which were required to be worn on a headband or a pair of glasses. Since that time, there has been significant development in surgical technique and device technology for bone-anchored hearing devices. A review of the current literature was conducted to describe these advancements and provide an up-to-date summary of the usage of osseointegrated bone-anchored hearing device in the management of hearing loss.

Effects of Frequency Compression and Frequency Transposition on Fricative and Affricate Perception in Listeners With Normal Hearing and Mild to Moderate Hearing Loss

The authors have demonstrated that the limited bandwidth associated with conventional hearing aid amplification prevents useful high-frequency speech information from being transmitted. The purpose of this study was to examine the efficacy of two popular frequency-lowering algorithms and one novel algorithm (spectral envelope decimation) in adults with mild to moderate sensorineural hearing loss and in normal-hearing controls. Participants listened monaurally through headphones to recordings of nine fricatives and affricates spoken by three women in a vowel-consonant context. Stimuli were mixed with speech-shaped noise at 10 dB SNR and recorded through a Widex Inteo IN-9 and a Phonak Naída UP V behind-the-ear (BTE) hearing aid. Frequency transposition (FT) is used in the Inteo and nonlinear frequency compression (NFC) used in the Naída. Both devices were programmed to lower frequencies above 4 kHz, but neither device could lower frequencies above 6 to 7 kHz. Each device was tested under four conditions: frequency lowering deactivated (FT-off and NFC-off), frequency lowering activated (FT and NFC), wideband (WB), and a fourth condition unique to each hearing aid. The WB condition was constructed by mixing recordings from the first condition with high-pass filtered versions of the source stimuli. For the Inteo, the fourth condition consisted of recordings made with the same settings as the first, but with the noise-reduction feature activated (FT-off). For the Naída, the fourth condition was the same as the first condition except that source stimuli were preprocessed by a novel frequency compression algorithm, spectral envelope decimation (SED), designed in MATLAB, which allowed for a more complete lowering of the 4 to 10 kHz input band. A follow-up experiment with NFC used Phonak's Naída SP V BTE, which could also lower a greater range of input frequencies. For normal-hearing and hearing-impaired listeners, performance with FT was significantly worse compared with that in the other conditions. Consistent with previous findings, performance for the hearing-impaired listeners in the WB condition was significantly better than in the FT-off condition. In addition, performance in the SED and WB conditions were both significantly better than in the NFC-off condition and the NFC condition with 6 kHz input bandwidth. There were no significant differences between SED and WB, indicating that improvements in fricative identification obtained by increasing bandwidth can also be obtained using this form of frequency compression. Significant differences between most conditions could be largely attributed to an increase or decrease in confusions for the phonemes /s/ and /z/. In the follow-up experiment, performance in the NFC condition with 10 kHz input bandwidth was significantly better than NFC-off, replicating the results obtained with SED. Furthermore, listeners who performed poorly with NFC-off tended to show the most improvement with NFC. Improvements in the identification of stimuli chosen to be sensitive to the effects of frequency lowering have been demonstrated using two forms of frequency compression (NFC and SED) in individuals with mild to moderate high-frequency sensorineural hearing loss. However, negative results caution against using FT for this population. Results also indicate that the advantage of an extended bandwidth as reported here and elsewhere applies to the input bandwidth for frequency compression (NFC/SED) when the start frequency is ≥4 kHz.

Middle Ear Implants for Rehabilitation of Sensorineural Hearing Loss

To systematically review the safety and efficacy of the 3 Food and Drug Administration-approved middle ear implant (MEI) systems currently in use for the rehabilitation of sensorineural hearing loss. MEDLINE and Cochrane Library databases were systematically searched by 2 independent reviewers. An initial search yielded 3,020 articles that were screened based on title and abstract. A full manuscript review of the remaining 80 articles was performed, of which 17 unique studies satisfied inclusion criteria and were evaluated. Variables including functional gain, speech recognition score improvement, audiometric threshold shift following surgery, adverse events, and patient reported outcome measures were recorded. Study quality was appraised according to author conflict of interest, prospective or retrospective study design, inclusion criteria, number of patients, proper use of study controls, outcome measures reported, length of follow-up, and level of evidence. Heterogeneous outcome reporting precluded meta-analysis; instead a structured review was performed using best available data. The majority of studies evaluating the safety and efficacy of MEIs are retrospective in nature with limited follow-up. To date, no prospective randomized controlled trial exists comparing contemporary air conduction hearing aid performance and MEI outcomes. Based on available data for patients with sensorineural hearing loss, functional gain and word recognition improvement seems similar between conventional hearing aids and MEIs, whereas patient-perceived outcome measures suggest that MEIs provide enhanced sound quality and eliminate occlusion effect.

The Influence of Audibility on Speech Recognition With Nonlinear Frequency Compression for Children and Adults With Hearing Loss

The primary goal of nonlinear frequency compression (NFC) and other frequency-lowering strategies is to increase the audibility of high-frequency sounds that are not otherwise audible with conventional hearing aid (HA) processing due to the degree of hearing loss, limited HA bandwidth, or a combination of both factors. The aim of the present study was to compare estimates of speech audibility processed by NFC with improvements in speech recognition for a group of children and adults with high-frequency hearing loss. Monosyllabic word recognition was measured in noise for 24 adults and 12 children with mild to severe sensorineural hearing loss. Stimuli were amplified based on each listener's audiogram with conventional processing (CP) with amplitude compression or with NFC and presented under headphones using a software-based HA simulator. A modification of the speech intelligibility index (SII) was used to estimate audibility of information in frequency-lowered bands. The mean improvement in SII was compared with the mean improvement in speech recognition. All but 2 listeners experienced improvements in speech recognition with NFC compared with CP, consistent with the small increase in audibility that was estimated using the modification of the SII. Children and adults had similar improvements in speech recognition with NFC. Word recognition with NFC was higher than CP for children and adults with mild to severe hearing loss. The average improvement in speech recognition with NFC (7%) was consistent with the modified SII, which indicated that listeners experienced an increase in audibility with NFC compared with CP. Further studies are necessary to determine whether changes in audibility with NFC are related to speech recognition with NFC for listeners with greater degrees of hearing loss, with a greater variety of compression settings, and using auditory training.

A new transcutaneous bone anchored hearing device - the Baha® Attract System: the first experience in Turkey.

In this study, we reported our experience with a new transcutaneous bone conduction hearing device, the Baha® Attract System. This multi-center clinical study included the first 12 patients (8 females, 4 males; mean age 27.6 years; range 5 to 65 years) in whom a new transcutaneous bone conduction system was implanted in Turkey. The mean air-bone gap was 41 dB. Bone smoothing around the implant was needed in five patients. We placed a sound processor in the fourth postoperative week for all patients. Our study results suggest that the new bone conduction implant is promising for the patients with conductive or mixed hearing loss who are unable to wear conventional air conduction hearing aid and comparable to percutaneous systems.