Objective: To evaluate the benefits of bilateral electrical stimulation for hearing-impaired adult subjects using the Nucleus 24 cochlear implant in a multicenter study, and to compare and quantify performance on speech perception measures in quiet and in noise and localization ability for unilateral and bilateral cochlear implant use. Design: Repeated single subject measures were carried out for each subject, with each subject serving as their own control. Assessment of unilateral and bilateral listening conditions for performance on tests of speech comprehension and sound localization were performed. Speech comprehension measures were performed in quiet at 0 degree azimuth and in the presence of background noise simultaneously presented from the same speaker and spatially separated by 90 degrees, at S+45°N45°and at S−45°N+45°. Test materials included Freiburger monosyllabic words, Oldenburger sentences, and the Hochmair-Schulz-Moser sentences. Tests of localization were performed in the horizontal plane with 12 speaker locations 30 degrees apart using a shortened sentence stimulus from the Hochmair-Schulz-Moser sentences at two possible presentation levels of 55 and 70 dB sound pressure level for assessment of directionality. The binaural advantage provided by bilateral stimulation was calculated with respect to each ear separately, classified as either the better or poorer performing ear for each speech material in quiet and in noise test conditions. For localization of sound, the binaural advantage was compared with left and right ears separately. Paired comparisons for performance data in all conditions were carried out by considering measurements for each subject in different conditions as paired observations and applying the Student's t test to determine the statistical difference between the data sets. Setting: Tertiary referral centers with a cochlear implant program. Patients: Thirty-seven profoundly hearing-impaired adults were enrolled in the study, 22 simultaneously and 15 sequentially bilaterally implanted. All patients received the Nucleus 24 cochlear implant and used the Nucleus SPrint or ESPrit 3G speech processor, with the vast majority using the ACE speech coding strategy. Results: For spatially separated speech in noise conditions, an interaural performance advantage for the ear closest to the speech source (i.e., with a superior signal to noise ratio) compared with that for the ear closest to the noise source (i.e., with an inferior signal to noise ratio) is consistently demonstrated regardless of whether it is the better or poorer performing ear closest to the speech signal. This is referred to as a significant binaural head-shadow benefit, resulting in a mean improvement between −10 dB and −11.4 dB in the critical signal to noise ratio required for 50% speech comprehension for the Oldenburger sentences and a mean improvement in the maximum score of 42% to 55% for the ear closest to the speech signal over the ear farthest away for the Hochmair-Schulz-Moser sentences. Bilateral stimulation i...

AutoNRT provides comparable accuracy to an average clinician but with the added benefit of significant time savings over manual recordings. This makes it a valuable tool for clinical measurement of ECAP threshold in cochlear implant recipients.

Objective: To clinically evaluate ForwardFocus in noise with experienced Nucleus V R cochlear implant (CI) recipients. Design: Listening performance with ForwardFocus was compared against the best in class directional microphone program (BEAM V R). Speech comprehension was tested with the Oldenburg sentence test with competing signals (stationary, three, six and 18-talker babble) in both co-located and spatially-separated listening environments. Additionally, normal hearing participants were tested monaurally in the same listening environments as a reference and to promote cross-study comparisons between CI clinical study outcomes. Study sample: Post-lingually deaf adult CI recipients (n ¼ 20) who were experienced users of the Nucleus sound processor (Cochlear Limited). Results: Improved speech comprehension was found with the ForwardFocus program compared to the BEAM program in a co-located frontal listening environment for both stationary and fluctuating competing signals. In spatially-separated environments ForwardFocus provided significant speech reception threshold (SRT) improvements of 5.8 dB for three-talker competing signals, respectively. Conclusions: ForwardFocus was shown to significantly improve speech comprehension in a wide range of listening environments. This technology is likely to provide significant improvements in real-world listening for CI recipients, given the clinically relevant performance outcomes in challenging dynamic noise environments, bringing their performance closer to their normal hearing peers.

As the CI users differed significantly in their SRT and their s50, a unified discrimination function for CI users must not be used. Further tailoring of the procedure may be required, especially for poorer CI performers.

No abstract

Objectives: To report on electrode array measurements for the Nucleus ® CI532 Slim Modiolar Electrode device including: ECAP thresholds, electrode impedances, and psychophysical comfort levels, as well as speech perception results pre-and post-operatively and standardized evaluations of quality of life. Methods: Forty-four subjects were implanted with the CI532. Electrically evoked compound action potential (ECAP) thresholds and impedances were measured using automatic Neural Response Telemetry intraoperatively, at activation and at six months post implant. Pre-and post-operative measures of words in quiet and sentences in noise were made in multiple languages. Quality of life was assessed using The Speech Spatial Qualities questionnaire (SSQ) and Glasgow Benefit Inventory (GBI). Results: Intra-operative ECAP thresholds were recorded successfully from 90% of electrodes tested. ECAP thresholds varied across the array and a post-hoc Dunn's test showed that median thresholds for electrodes E1-E13 were significantly greater than those for E17-E22 (all P < 0.001). Impedances increased significantly between surgery and activation. Speech recognition scores for words in quiet and sentences in noise showed a significant improvement for the group at six months, when using the cochlear implant, compared with pre-operative performance (P < 0.001). There was a significant increase compared to pre-operative ratings for all sections of the SSQ at six months post activation (P < 0.001). The GBI gave scores significantly above zero for the 'general' subscale and total score. Conclusion: Objective ECAP and impedance measures for this new electrode array were as expected and similar to results reported for other array types. Speech perception and quality of life improved significantly following implantation. (Registered as NCT02392403 on ClinicalTrials.gov PRS)

A study was conducted to compare the new MED-EL TEMPO+ ear-level speech processor with the CIS PRO+ body-worn processor in the COMBI 40/COMBI 40+ implant system. Speech tests were performed in 46 experienced subjects in two test sessions approximately 4 weeks apart. Subjects were switched over from the CIS PRO+ to the TEMPO+ in the first session and used only the TEMPO+ in the time between the two sessions. Speech tests included monosyllabic word tests and sentence tests via the telephone. An adaptive noise method was used to adjust each subject’s scores to approximately 50%. Additionally, subjects had to complete a questionnaire based on their 4 weeks of experience with the TEMPO+. The speech test results showed a statistically significant improvement in the monosyllabic word scores with the TEMPO+. In addition, in the second session, subjects showed a significant improvement when using the telephone with the TEMPO+, indicating some learning in this task. In the questionnaire, the vast majority of subjects found that the TEMPO+ allows equal or better speech understanding and rated the sound quality of the TEMPO+ higher. All these objective and subjective results indicate the superiority of the TEMPO+ and are mainly attributed to a new coding strategy called CIS+ and its implementation in the TEMPO+. In other words, based on the results of this study, it appears that after switching over from the CIS PRO+ to the TEMPO+, subjects are able to maintain or even improve their own speech understanding capability.

Individual speech intelligibility was measured in quiet and noise for cochlear Implant recipients upgrading from the Freedom to the CP900 series sound processor. The postlingually deafened participants (n = 23) used either Nucleus CI24RE or CI512 cochlear implant, and currently wore a Freedom sound processor. A significant group mean improvement in speech intelligibility was found in quiet (Freiburg monosyllabic words at 50 dBSPL) and in noise (adaptive Oldenburger sentences in noise) for the two CP900 series SmartSound programs compared to the Freedom program. Further analysis was carried out on individual’s speech intelligibility outcomes in quiet and in noise. Results showed a significant improvement or decrement for some recipients when upgrading to the new programs. To further increase speech intelligibility outcomes when upgrading, an enhanced upgrade procedure is proposed that includes additional testing with different signal-processing schemes. Implications of this research are that future automated scene analysis and switching technologies could provide additional performance improvements by introducing individualized scene-dependent settings.