Virtual cochlear implantation for personalized rehabilitation of profound hearing loss.

In cochlear implantation, current preoperative planning procedures allow for estimating how far a specific implant will reach into the inner ear of the patient, which is important to optimize hearing preservation and speech perception outcomes. Here we report on the development of a methodology that goes beyond current planning approaches: the proposed model does not only estimate specific outcome parameters but allows for entire, three-dimensional virtual implantations of patient-specific cochlear anatomies with different types of electrode arrays. The model was trained based on imaging datasets of 186 human cochleae, which contained 171 clinical computer tomographies (CTs) of actual cochlear implant patients as well as 15 high-resolution micro-CTs of cadaver cochleae to also reconstruct the refined intracochlear structures not visible in clinical imaging. The model was validated on an independent dataset of 141 preoperative and postoperative clinical CTs of cochlear implant recipients and outperformed all currently available planning approaches, not only in terms of accuracy but also regarding the amount of information that is available prior to the actual implantation.

CI decision making and expectations by older adults.

OBJECTIVE: To document and analyze the cochlear implant (CI) decision-making process of hearing-impaired older adults. The aim of this study is to assess what support could be helpful during this process in order to improve care delivery. METHODS: 32 older adult CI recipients (≥ 60 years) with severe to profound sensorineural hearing loss were interviewed about their CI decision-making process 3-12 months after obtaining their first CI. RESULTS: Minimal information was provided to CI candidates by hearing aid acousticians or patient associations. High to very high expectations were reported by patients concerning issues beyond hearing improvement per se. Even though not all expectations were fulfilled by the CI, nearly all recipients who used an implant for at least six months would recommend a CI to others. DISCUSSION: We identified an opportunity for those professionals to play a greater role in supporting older CI candidates during the decision-making process. It is desirable to establish a comprehensive network of hearing care professionals to collaborate with CI clinics. CONCLUSION: In order to support older patients adequately in deciding about CI, intensive training should be offered to hearing care professionals in order to provide realistic expectations and reduce fear and uncertainty about the implantation process. These topics need to be communicated in a professional manner and adapted to the candidate's age and personality.

Development and validation of the audio processor satisfaction questionnaire (APSQ) for hearing implant users.

Objective: The satisfaction experienced with using an audio processor is very important to hearing implant system users. Currently there are no measures that can be used to assess user satisfaction with an audio processor. This study aims to develop and validate a specific and standardised questionnaire that focuses on user satisfaction with their audio processor.Design: A preliminary version of the questionnaire was initially developed by experts in the field. Following validation of these results, the final version of the Audio Processor Satisfaction Questionnaire (APSQ) was developed consisting of 15 items. Item analyses and questionnaire validation measurements were assessed.Study sample: Sixty-nine subjects were recruited and asked to complete the APSQ twice within 2-4 weeks.Results: Subjects reported a high user satisfaction with the questionnaire and with their audio processor. The questionnaire had good reliability and results for test-retest reliability were high and significant across all items and across subscale analyses.Conclusion: Item analyses and reliability analyses show that the questionnaire is a valid and reliable tool to assess user satisfaction across different audio processors and hearing implant systems. The APSQ is a quick and easy tool to measure user satisfaction with their audio processor.

Introducing real-life listening features into the clinical test environment: Part II: Measuring the hearing performance and evaluating the listening effort of individuals with a hearing implant.

Objectives: The controlled clinical test environment is very different from real-life listening situations, where the presence of additional speakers and variations in background noise signals can affect listening performances. The primary objective of this study is to reduce the gap between clinical results and real-life performances that are reported for many hearing implant users. Methods: Similar to Part I of this study, hearing performance and sound perception are evaluated using the following tests: (i) the Roving Level Test, (ii) the Just Understanding Speech Test, (iii) the Performance Perceptual Test, (iv) the Visual Analogue Scale to evaluate the perceived listening effort required for a range of background noise levels, and (v) the Hearing Implant Sound Quality questionnaire. All subjects recruited for this study used MED-EL hearing implant systems. Results: Results show that, similar to normal hearing listeners, hearing implant users tend to accurately estimate their hearing abilities, and both listening effort and speech recognition thresholds tend to increase with increasing noise. Discussion: The proposed test battery for evaluating speech understanding and listening effort were suitable for use in this study as all of the implant users were able to complete the tests. This test battery can be used to provide audiologists with further information relating to real-life listening performances. Conclusion: Evaluating the self-estimated and verified performance measurements of hearing implant users in real-life listening situations are essential for providing information regarding the discrepancies observed between the objective and subjective reports of hearing difficulties.

Analysis of Different Approaches for Clinical Cochlear Coverage Evaluation After Cochlear Implantation.

HYPOTHESIS: Methods for cochlear coverage determination vary in their accuracy and are hence not equally reliable. BACKGROUND: The audiological outcome after cochlear implantation is known to depend on several factors. One factor shown to positively correlate with speech perception is the insertion angle. This parameter is one of the ways to describe the fraction of the cochlea spiral exposed to electric stimulation after implantation, also known as cochlear coverage, which itself is dependent on the length and type of electrode array as well as the size and shape of the implanted cochlea. While the assessment of cochlear coverage as the insertion angle is quick and uncomplicated, the accuracy of representing the relative fraction of the cochlea exposed to electric stimulation by this single measurement value remains unknown. METHODS: Both the cochlea spiral and implanted electrode array of N = 10 cochlear implant patients were traced within clinical imaging data and processed to derive the respective cochlear coverage values. These values were compared to ones derived with alternative measures like the insertion angle as well as other methods to yield the accuracy and reliability of these approaches. RESULTS: The insertion angle as well as two novel approaches were found to be superior to all other analyzed assessment options and well suited for clinical cochlear coverage evaluations. CONCLUSION: Insertion angle measurements are well suited for cochlear coverage determination, especially regarding retrospective analyses. Prospective studies independent of anatomical irregularities should be performed with the newly proposed approaches.

A Novel Method for Clinical Cochlear Duct Length Estimation toward Patient-Specific Cochlear Implant Selection.

OBJECTIVE: In the field of cochlear implantation, the current trend toward patient-specific electrode selection and the achievement of optimal audiologic outcomes has resulted in implant manufacturers developing a large portfolio of electrodes. The aim of this study was to bridge the gap between the known variability of cochlea length and this electrode portfolio. DESIGN: Retrospective analysis on cochlear length and shape in micro-computed tomography and cone beam computed tomography data. SETTING: Tertiary care medical center. SUBJECTS AND METHODS: A simple 2-step approach was developed to accurately estimate the individual cochlear length as well as the projected length of an electrode array inside the cochlea. The method is capable of predicting the length of the cochlea and the inserted electrode length at any specific angle. Validation of the approach was performed with 20 scans of human temporal bones (micro-computed tomography) and 47 pre- and postoperative clinical scans (cone beam computed tomography). RESULTS: Mean ± SD absolute errors in cochlear length estimations were 0.12 ± 0.10 mm, 0.38 ± 0.26 mm, and 0.71 ± 0.43 mm for 1, 1.5, and 2 cochlea turns, respectively. Predicted insertion angles based on clinical cone beam computed tomography data showed absolute deviations of 27° ± 18° to the corresponding postoperative measurements. CONCLUSION: With accuracy improvements of 80% to 90% in comparison with previously proposed approaches, the method is well suited for the use in individualized cochlear implantation.

Do you hear the noise? The German matrix sentence test with a fixed noise level in subjects with normal hearing and hearing impairment.

OBJECTIVE: The aim of this study was to determine the relationship between hearing loss and speech reception threshold (SRT) in a fixed noise condition using the German Oldenburg sentence test (OLSA). DESIGN: After training with two easily-audible lists of the OLSA, SRTs were determined monaurally with headphones at a fixed noise level of 65 dB SPL using a standard adaptive procedure, converging to 50% speech intelligibility. STUDY SAMPLE: Data was obtained from 315 ears of 177 subjects with hearing losses ranging from -5 to 90 dB HL pure-tone average (PTA, 0.5, 1, 2, 3 kHz). RESULTS: Two domains were identified with a linear dependence of SRT on PTA. The SRT increased with a slope of 0.094 ± 0.006 dB SNR/dB HL (standard deviation (SD) of residuals = 1.17 dB) for PTAs < 47 dB HL and with a slope of 0.811 ± 0.049 dB SNR/dB HL (SD of residuals = 5.54 dB) for higher PTAs. CONCLUSION: The OLSA can be applied to subjects with a wide range of hearing losses. With 65 dB SPL fixed noise presentation level the SRT is determined by listening in noise for PTAs < ∼47 dB HL, and above it is determined by listening in quiet.