Audiological and clinical outcomes of a transcutaneous bone conduction hearing implant: Six-month results from a multicentre study.

OBJECTIVES: To compare the hearing performance of patients with conductive and mild mixed hearing loss and single-sided sensorineural deafness provided with a new transcutaneous bone conduction hearing implant (the Baha Attract System) with unaided hearing as well as aided with a sound processor on a softband. Furthermore, to evaluate safety and subjective benefit before and after implantation of the test device. PARTICIPANTS: Fifty-four adult patients in five participating centres were enrolled in this prospective study. Baseline data were collected during a pre-operative visit, and after a softband trial, all patients were implanted unilaterally. Follow-up visits were scheduled at 10 days, 4, 6, 12 weeks and 6 months. MAIN OUTCOME MEASURES: Free-field hearing thresholds pure-tone average (PTA4 in dB HL; mean threshold at 500, 1000, 2000, 4000 Hz; primary outcome measure). Individual free-field hearing thresholds, speech recognition in quiet and in noise, soft tissue status during follow-up and subjective benefit as measured with the Abbreviated Profile of Hearing Aid Benefit (APHAB), Speech, Spatial and Qualities of Hearing Scale (SSQ) and Health Utilities Index (HUI) questionnaires. RESULTS: Implantation of the Baha Attract System resulted in favourable audiological outcomes compared to unaided conditions. On the primary outcome parameter, a statistically significant improvement was observed compared to unaided hearing for the patients with conductive/mixed hearing loss (mean PTA4 difference -20.8 dB HL, SD 9.8; P < 0.0001) and for the patients with single-sided sensorineural deafness (SSD) (mean PTA4 difference -21.6 dB HL, SD 12.2; P < 0.0001). During all audiology tests, the non-test ear was blocked. Statistically significant improvements were also recorded in speech tests in quiet and noise compared to unaided hearing for the conductive/mixed hearing loss group and for speech in quiet in the SSD group. Compared to the pre-operative measurement with softband, no significant differences were recorded in the PTA4 free-field hearing threshold or the other audiological outcomes in either of the groups (P > 0.05). Soft tissue-related issues observed during follow-up included numbness, pain/discomfort at the implant site and to a lesser extent pressure-related skin complications. A declining trend was noted in the rate of these complications during follow-up. Approximately 20% of patients reported some degree of numbness and 38% (slight) pain/discomfort at final follow-up of 6 months. Good results on the subjective benefit questionnaires were observed, with statistically significant improvements on APHAB and SSQ questionnaires, and on the hearing attribute of HUI3. CONCLUSIONS: The Baha Attract System provided a significant improvement in hearing performance and subjective benefit compared to the pre-operative unaided condition (with the non-test ear blocked). Hearing performance of the Baha Attract was similar to a test situation with the same sound processor on a softband. A proportion of the patients reported numbness and pain/discomfort at the implant site during follow-up, especially during the first post-operative weeks. Based on the results of the current multicentre study, the Baha Attract can be considered as a treatment option for patients with the aforementioned hearing losses. Especially in the SSD patients, a careful selection procedure is warranted. Therefore, a pre-operative trial should be part of the decision-making process before fitting a patient with the Baha Attract System.

Standardized phylogenetic and molecular evolutionary analysis applied to species across the microbial tree of life.

There is growing interest in reconstructing phylogenies from the copious amounts of genome sequencing projects that target related viral, bacterial or eukaryotic organisms. To facilitate the construction of standardized and robust phylogenies for disparate types of projects, we have developed a complete bioinformatic workflow, with a web-based component to perform phylogenetic and molecular evolutionary (PhaME) analysis from sequencing reads, draft assemblies or completed genomes of closely related organisms. Furthermore, the ability to incorporate raw data, including some metagenomic samples containing a target organism (e.g. from clinical samples with suspected infectious agents), shows promise for the rapid phylogenetic characterization of organisms within complex samples without the need for prior assembly.

A Multinational Cost-Consequence Analysis of a Bone Conduction Hearing Implant System-A Randomized Trial of a Conventional vs. a Less Invasive Treatment With New Abutment Technology.

Background: It is hypothesized that, for patients with hearing loss, surgically placing an implant/abutment combination whilst leaving the subcutaneous tissues intact will improve cosmetic and clinical results, increase quality of life (QoL) for the patient, and reduce medical costs. Here, incremental costs and consequences associated with soft tissue preservation surgery with a hydroxyapatite (HA)-coated abutment (test) were compared with the conventional approach, soft tissue reduction surgery with an all-titanium abutment (control). Methods: A cost-consequence analysis was performed based on data gathered over a period of 3 years in an open randomized (1:1) controlled trial (RCT) running in four European countries (The Netherlands, Spain, France, and Sweden). Subjects with conductive or mixed hearing loss or single-sided sensorineural deafness were included. Results: During the first year, in the Netherlands (NL), France (FR), and Spain (ES) a net cost saving was achieved in favor of the test intervention because of a lower cost associated with surgery time and adverse event treatments [NL €86 (CI -50.33; 219.20), FR €134 (CI -3.63; 261.30), ES €178 (CI 34.12; 97.48)]. In Sweden (SE), the HA-coated abutment was more expensive than the conventional abutment, which neutralized the cost savings and led to a negative cost (SE €-29 CI -160.27; 97.48) of the new treatment modality. After 3 years, the mean cost saving reduced to €17 (CI -191.80; 213.30) in the Netherlands, in Spain to €84.50 (CI -117.90; 289.50), and in France to €80 (CI -99.40; 248.50). The mean additional cost in Sweden increased to €-116 (CI -326.90; 68.10). The consequences in terms of the subjective audiological benefit and Health-related quality of life (HRQoL) were comparable between treatments. A trend was identified for favorable results in the test group for some consequences and statistical significance is achieved for the cosmetic outcome as assessed by the clinician. Conclusions: From this multinational cost-consequence analysis it can be discerned that health care systems can achieve a cost saving during the first year that regresses after 3 years, by implementing soft tissue preservation surgery with a HA-coated abutment in comparison to the conventional treatment. The cosmetic results are better. (sponsored by Cochlear Bone Anchored Solutions AB; Clinical and health economic evaluation with a new Baha® abutment design combined with a minimally invasive surgical technique, ClinicalTrials.gov NCT01796236).

Application and Interpretation of Resonance Frequency Analysis in Auditory Osseointegrated Implants: A Review of Literature and Establishment of Practical Recommendations.

OBJECTIVE: To establish standardization of implant stability measurements in auditory osseointegrated implants by means of resonance frequency analysis (RFA) through reviewing the currently published literature. METHODS: Studies reporting on RFA in auditory osseointegrated implants were identified, and the outcomes and the way these were reported were evaluated. RESULTS: Thirteen clinical studies reporting RFA outcomes of auditory osseointegrated implants were identified and analyzed, which demonstrated variations in methodology and reporting of data. The different reporting standards made a meta-analysis impossible. Heterogeneity and limitations were found in reporting of the types of implants, abutments, and SmartPegs used; study population sizes; follow-up duration; and, reporting of the implant stability quotient (ISQ). CONCLUSION: RFA is an interesting outcome of clinical studies on auditory osseointegrated implant research and might have potential as a clinically relevant tool for assessing implant stability. Because of the heterogeneous data that have been reported to date, the following guidelines for standardization of application and reporting were established. The implant and abutment type and length, and the type of SmartPeg should always be stated. Absolute stand-alone ISQ values should not be interpreted individually. ISQ values are at this moment most meaningful as a trend in the individual patient or in a population over time. No conclusions should be based on individual ISQ values. Standardized time points for RFA in research should be determined prospectively, with surgery as a baseline. After abutment replacement, individual ISQ trends from baseline cannot be interpreted anymore if the abutments differ in length.

Training phonological awareness skills in children with Down syndrome.

Increasingly, children with Down syndrome receive literacy instruction based on a phonological awareness philosophy with the expectation of acquiring functional reading skills. Previous research demonstrates that a phonological awareness based reading programme delivers excellent results in terms of literacy acquisition and improvements in speech production for children with speech and language delays. Unfortunately, little research exists to support the effectiveness of this approach for children with Down syndrome. The current research study examined using a phonological awareness based intervention programme with three children with Down syndrome (aged 7;2, 8;4, and 8;10). A multiple baseline across behaviours design was selected. The intervention programme focused on the key skills of alliteration detection, phoneme isolation, spelling of orthographically regular words and rhyme detection. Two tasks (comprehension of passive structures and spatial structures) were selected as control behaviours. Phoneme segmentation and speech intelligibility were selected to investigate generalisation of intervention targets to other related skill areas. The results indicated that the participants improved the phonological awareness skills targeted in the intervention programme. Unfortunately, no generalisation to other areas of phonological awareness was noted. In summary, the results indicate that children with Down syndrome can benefit from a phonological awareness based approach to literacy.

Early phonological awareness and reading skills in children with Down syndrome.

Increasingly, children with Down syndrome receive literacy instruction with the expectation of acquiring functional reading skills. Unfortunately, little is known about the processes underlying literacy skills in this special population. Phonological awareness contributes to literacy development in typically developing children, however, there is inconclusive evidence about these skills in younger children with Down syndrome. 9 children with Down syndrome (5.6-8.10 years) participated in this investigation. Due to the paucity of standardised phonological awareness measures for children with special needs, in particular children with Down syndrome, a variety of tasks were adapted from the literature. The assessment battery examined the skills of phonological awareness, literacy, speech production, expressive language, hearing acuity, speech perception, and auditory-visual memory. The results suggest that children with Down syndrome are at risks for reading acquisition difficulties due to reduced phonological awareness skills. These deficits are in addition to delays caused by reduced cognitive skills. Only one of the participants was able to demonstrate rhyme awareness, which may have been due to task effects. Written word recognition ability was correlated with tests of phonemic awareness, and error analysis of the spelling and non-word reading tasks suggested grapheme-phoneme connections deficits. Further research is needed to determine the best methods of assessment and intervention for phonological awareness in children with Down syndrome.

Improving the classroom listening skills of children with Down syndrome by using sound-field amplification.

Many children with Down syndrome have fluctuating conductive hearing losses further reducing their speech, language and academic development. It is within the school environment where access to auditory information is crucial that many children with Down syndrome are especially disadvantaged. Conductive hearing impairment which is often fluctuating and undetected reduces the child's ability to extract the important information from the auditory signal. Unfortunately, the design and acoustics of the classroom leads to problems in extracting the speech signal through reduced speech intensity due to the increased distance of the student from the teacher in addition to masking from excessive background noise. One potential solution is the use of sound-field amplification which provides a uniform amplification to the teacher's voice through the use of a microphone and loudspeakers. This investigation examined the efficacy of sound-field amplification for 4 children with Down syndrome. Measures of speech perception were taken with and without the sound-field system and found that the children perceived significantly more speech in all conditions where the sound-field system was used (p < .0001). Importantly, listening performance with the sound-field system was not affected by reducing the signal-to-noise ratio through increasing the level of background noise. In summary, sound-field amplification provides improved access to the speech signal for children with Down syndrome and as a consequence leads to improved classroom success.

Facilitating speech and language development in children with cochlear implants using computer technology.

Little research exists to support the use of computer software with children with cochlear implants. The present study sought to address this deficit and investigate the efficacy of using computer technology to facilitate the speech and language skills of five children with cochlear implants. Participants received 8 months of intervention focusing on the development of speech production and phonological awareness skills using the SpeechViewer III and Earobics computer software programs. Statistically significant gains were achieved in speech production, receptive language, syllabic and phonemic awareness, and non-word reading. Findings suggest that the use of computer software may be an efficient method for improving the speech and language skills of children with cochlear implants.

Long-term stability, survival, and tolerability of a novel osseointegrated implant for bone conduction hearing: 3-year data from a multicenter, randomized, controlled, clinical investigation.

OBJECTIVE: To compare the 3-year stability, survival, and tolerability of 2 osseointegrated implants for bone conduction hearing: a wide 4.5-mm-diameter moderately roughened implant with a rounded 6-mm abutment (test) and a 3.75-mm diameter as-machined implant with a conically shaped 5.5-mm abutment (control). STUDY DESIGN: In this randomized, prospective, controlled, multicenter clinical study, 77 adult patients were included. Test and control implants were randomly assigned in proportions of 2:1. The implants were loaded with the sound processor from 6 weeks postimplantation. Follow-up after surgery was conducted at 10 days; at 4, 6, 8, and 12 weeks; and at 6, 12, 24, and 36 months after surgery. At every visit, implant stability quotient (ISQ) values were recorded by means of resonance frequency analysis (RFA), and skin reactions were evaluated according to Holgers' classification. RESULTS: Statistically significantly higher mean ISQ values were recorded for the test implant compared with the control implant at each evaluation time point. Between 2 and 3 years after surgery, ISQ values decreased but remained above baseline values. Implant survival was high for both implants: 96.2% of the test implants and 100% of the control implants survived these 3 years. Statistically significantly improved soft tissue outcomes were observed in the test implant group. CONCLUSION: This extensive long-term clinical investigation demonstrated that the test implant is more stable in terms of ISQ-values and provides high tolerability for the soft tissue. The results show that implant loading at 6 weeks is safe.

Improving the Accuracy of Baha® Fittings through Measures of Direct Bone Conduction.

OBJECTIVES: Variability in Baha® sound processor fittings may arise from the nature of the implant-to-bone transmission as well as transcranial attenuation for patients with single-sided sensorineural deafness (SSD). One method of improving the predictability of Baha fittings is to measure the individual patient's actual bone conduction thresholds, thereby removing the influences of skin thickness and/or the implant location site. METHODS: Twenty adult wearers of the Baha bone conduction implant system participated in the study. Direct bone conduction thresholds were obtained through the BC Direct function of the Baha Fitting Software combined with the Cochlear Baha BP100 sound processor. For comparison, the masked and unmasked bone conduction responses of the patients were collected through standard audiometric testing techniques. Test-retest reliability measurement was performed for all participants. Data for each frequency and frequency range were analyzed separately. RESULTS: The results confirm the improved transmission of sound through the implant rather than transcutaneously through the skin. On average, the BC Direct thresholds were closer to the patient's unmasked thresholds than the masked values. In subjects with SSD, BC Direct results were poorer than contra-lateral bone conduction thresholds, most likely due to transcranial attenuation. The test-retest reliability for the BC Direct measurements was within +/-5 dB. The comparison of preferred amplification, based on direct bone conduction or bone conduction audiometry, found higher agreement for fittings based on direct bone conduction measurements. CONCLUSION: While the transfer function between the implant and the skin can be predicted on average, there are a number of patients for whom measurement is essential to determine the required amplification. These were patients with: 1) SSD, 2) asymmetrical hearing loss, 3) unusual implant location or skull formation, and 4) users of Testband or Softband. The result for the clinician is that a fitting can take place with less fine-tuning and a greater understanding of the variability of bone conducted sound transmission.

Hearing performance benefits of a programmable power baha® sound processor with a directional microphone for patients with a mixed hearing loss.

OBJECTIVES: New signal processing technologies have recently become available for Baha® sound processors. These technologies have led to an increase in power and to the implementation of directional microphones. For any new technology, it is important to evaluate the degree of benefit under different listening situations. METHODS: Twenty wearers of the Baha osseointegrated hearing system participated in the investigation. The control sound processor was the Baha Intenso and the test sound processor was the Cochlear™ Baha® BP110power. Performance was evaluated in terms of free-field audibility with narrow band noise stimuli. Speech recognition of monosyllabic phonetically balanced (PB) words in quiet was performed at three intensity settings (50, 65, and 80 dB sound pressure level [SPL]) with materials presented at 0 degrees azimuth. Speech recognition of sentences in noise using the Hearing in Noise Test (HINT) in an adaptive framework was performed with speech from 0 degrees and noise held constant at 65 dB SPL from 180 degrees. Testing was performed in both the omni and directional microphone settings. Loudness growth was assessed in randomly presented 10 dB steps between 30 and 90 dB SPL to narrow band noise stimuli at 500 Hz and 3,000 Hz. RESULTS: The test sound processor had significantly improved high frequency audibility (3,000-8,000 Hz). Speech recognition of PB words in quiet at three different intensity levels (50, 65, and 80 dB SPL) indicated a significant difference in terms of level (P<0.0001) but not for sound processor type (P>0.05). Speech recognition of sentences in noise demonstrated a 2.5 dB signal-to-noise ratio (SNR) improvement in performance for the test sound processor. The directional microphone provided an additional 2.3 dB SNR improvement in speech recognition (P<0.0001). Loudness growth functions demonstrated similar performance, indicating that both sound processors had sufficient headroom and amplification for the required hearing loss. CONCLUSION: The test sound processor demonstrated significant improvements in the most challenging listening situation (speech recognition in noise). The implementation of a directional microphone demonstrated a further potential improvement in hearing performance. Both the control and test sound processors demonstrated good performance in terms of audibility, word recognition in quiet and loudness growth.

Challenges and recent developments in sound processing for Baha®.

Osseointegrated auditory implants such as Baha(®) provide an efficient pathway for sound delivery and an excellent amplification choice for patients with conductive or mixed hearing loss or single-sided sensorineural deafness. But at the same time, bone conduction hearing provides a number of key challenges that need to be addressed. One solution is computer-based fitting software to measure in-situ thresholds directly through the Baha sound processor and to individually prescribe amplification settings based on the patient's hearing loss and degree of transcranial attenuation. Additionally, technologies such as automatic directional microphones and noise reduction systems further improve hearing performance in noisy situations. This paper highlights recent technological innovations and summarizes data on the advantages for the Baha patient population using the sound processing capabilities available in the latest Baha sound processors.

Stability, survival, and tolerability of a novel baha implant system: six-month data from a multicenter clinical investigation.

OBJECTIVE: Determination of the difference in implant stability between a novel Baha implant system (test) and the previous-generation implant system (control). METHODS: In an open, randomized, prospective multicenter clinical investigation, 77 adult patients with Baha implants were included. Test and control implants were randomly assigned in proportions of 2:1. Implant stability quotient (ISQ) values were recorded using resonance frequency analysis at the time of implantation and at 10 days, at 4, 6, 8, and 12 weeks, and at 6 months after surgery. Skin reactions were evaluated according to the Holgers classification. Sound processor fitting was performed from 6 weeks after implantation. RESULTS: Significantly higher mean ISQ values, measured between 0 and 6 months, were obtained for test compared to control implants (70.4 versus 65.4, p < 0.0001). Statistically significant differences were obtained for the study population as a whole and for the subgroup of patients loaded at 6 ± 1 weeks after implant surgery (63.6% of patients). Up to 12 weeks, Holgers rates were comparable, whereas at 6 months, more skin reactions (Grades 1 and 2) were observed in the control implant group. No reduction in mean ISQ values was observed after implant loading. CONCLUSION: The test implant showed higher mean ISQ values at the time of placement and over time. The level of osseointegration reached with the implants in adults as early as 6 weeks after implantation was sufficient to support the sound processor. The test implant system is expected to provide additional benefits related to the improvement of the degree of osseointegration, especially for patients with thin or compromised bone.

Baha solutions for patients with severe mixed hearing loss.

Patients with a mixed hearing loss present special challenges. The amplification demands of mixed hearing loss can drive powerful digital hearing aids to their limits and introduce distortion through saturation. Conversely, the Baha System effectively bypasses the conductive component and focuses on compensating for the sensorineural component of the hearing loss. Ten patients with a mixed hearing loss participated in the present study. Results indicate that Baha provided significant benefits (p < 0.01) over conventional air conduction hearing instruments across the dimensions of audibility, speech understanding and sound quality. Given the increased output force of the latest Baha instruments, once the conductive component of a severe mixed hearing loss becomes greater than 30 dB, a Baha should be considered and evaluated on audiological grounds alone to provide optimal amplification.

Multiple-channel non-linear power hearing instruments for children with severe hearing impairment: long-term follow-up.

The long-term benefits of multiple-channel non-linear technology for children with severe hearing impairment have yet to be fully investigated over the longer term. Twenty-one children with severe hearing loss participated in a study comparing performance on measures of audibility, speech understanding (in quiet and noise) and listening situations between the children's current analog hearing aids and a test hearing aid with multiple-channel non-linear compression (DigiFocus II Compact Power). Results were obtained from the children at 2 weeks, 8 weeks, 6 months and 12 months following the fitting of a multiple-channel non-linear hearing instrument. Compared with the children's own hearing instruments, the test instruments provided improved audibility, improvement in speech understanding in quiet and noise, and an improvement in listening skills The gains in speech understanding were greater in noise than in quiet, suggesting that the test hearing instrument provided greatest improvement when listening to speech in noise. While performance increased over time, there was no statistically significant evidence to support continued acclimatization.