Objective: This study compared speech perception benefits in adults implanted with the HiResolution^TM (HiRes) Bionic Ear who used both conventional and HiRes sound processing. A battery of speech tests was used to determine which formats were most appropriate for documenting the wide range of benefit experienced by cochlear-implant users. Study Design: A repeated-measures design was used to assess postimplantation speech perception in adults who received the HiResolution Bionic Ear in a recent clinical trial. Patients were fit first with conventional strategies and assessed after 3 months of use. Patients were then switched to HiRes sound processing and assessed again after 3 months of use. To assess the immediate effect of HiRes sound processing on speech perception performance, consonant recognition testing was performed in a subset of patients after 3 days of HiRes use and compared with their 3-month performance with conventional processing. Setting: Subjects were implanted and evaluated at 19 cochlear implant programs in the USA and Canada affiliated primarily with tertiary medical centers. Patients: Patients were 51 postlinguistically deafened adults. Main Outcome Measures: Speech perception was assessed using CNC monosyllabic words, CID sentences and HINT sentences in quiet and noise. Consonant recognition testing was also administered to a subset of patients (n = 30) using the Iowa Consonant Test presented in quiet and noise. All patients completed a strategy preference questionnaire after 6 months of device use. Results: Consonant identification in quiet and noise improved significantly after only 3 days of HiRes use. The mean improvement from conventional to HiRes processing was significant on all speech perception tests. The largest differences occurred for the HINT sentences in noise. Ninety-six percent of the patients preferred HiRes to conventional sound processing. Ceiling effects occurred for both sentence tests in quiet. Conclusions: Although most patients improved after switching to HiRes sound processing, the greatest differences were seen in the ‘poor’ performers because ‘good’ performers often reached ceiling performance, especially on tests in quiet. Future evaluations of cochlear-implant benefit should make use of more difficult measures, especially for ‘good’ users. Nonetheless, a range of difficulty must remain in test materials to document benefit in the entire population of implant recipients.

The Minimal Auditory Capabilities (MAC) Battery was administered individually to 75 hearing aid users with profound sensorineural hearing loss. The purposes of the study were (1) to determine the reliability of the individual tests, their range of difficulty, and their intercorrelations; (2) to undertake a standardization procedure based on data from this population; and (3) to assess the need for revisions. Difficulty ranged gradually from a mean score of 86% correct for the Spondee Same/Different test to a mean of 16% for the NU 6 monosyllabic word test. Alpha estimates of reliability were 0.89 or higher for all but the Everyday Sounds test (0.85), the Question/$tatement test (0.83), and the Spondee Same/Different test (0.81). Along with the reliability and range of difficulty results, intertest correlations provided no indication that any of the tests should be discarded. In the standardization of the MAC, the mean score correct on each test was set at 100 and the standard deviation at 10. Prepared tables for immediate conversion of a raw score to a standardized score for any test are included in an Appendix. Among revisions, also listed in the Appendix, the CID Everyday Sentences test was reduced to 20 items from 40, the SPIN High-Context Sentences were assigned key words, and the assessment of distinctive feature identification was discontinued. BACKGROUND

Approved by the US Food and Drug Administration after carefully monitored investigational clinical trials in both the adult and pédiatrie populations, it has now been implanted in approximately 3,000 patients worldwide. A fully flexible, programmable system, the Clarion offers multiple strategies and options in speech processing. The coupling mode, the stimulating waveform, and the temporal pattern of stimulation can be selected to allow each patient an opportunity to be fitted with the strategy that offers the highest level of performance. This paper describes the current status of the Clarion system. However, Clarion development has been a dynamic process, and from its initial introduction in 1991, the system has been modified and continually improved. The process of improvement and advancement is ongoing. New speech processing strategies and hardware developments are briefly summarized at the conclusion of this paper.

A four-channel bipolar cochlear implant developed at the University of California at San Francisco through a long series of animal experiments, engineering development studies, and speech processor design-optimization studies with experimental prosthetic devices in patients, is now being applied in a clinical investigation, as a joint project of the UCSF group and the manufacturer, Storz Medical Instruments.