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Importance Hearing loss, especially moderate to severe forms, has the potential to negatively affect an individual’s physical, social, emotional, and cognitive well-being. Moreover, having ineffective binaural hearing increases difficulty understanding speech in noise and leads to a greater degree of social isolation and loneliness and a reduced quality of life (QoL). Objective To explore the audiometric and holistic effects of cochlear implantation in a group of adults 65 years or older compared with an optimized bilateral hearing aid condition. Design, Setting, and Participants This ad hoc secondary analysis of a prospective, single-subject, repeated-measures nonrandomized clinical trial included 13 cochlear implantation centers across the United States. Participants 65 years or older with postlingual bilateral moderate-to-profound sensorineural hearing loss with aided Consonant-Vowel Nucleus-Consonant (CNC) word scores in quiet of 40% or less in the ear to undergo implantation and 50% or less in the contralateral ear were included in the analysis. Baseline QoL testing was performed after 1 month of optimized bilateral hearing aid use. Participants were enrolled from February 20, 2017, to May 3, 2018, and follow-up was completed December 21, 2018. Data were analyzed from March 25, 2019, to March 31, 2020. Interventions Unilateral implantation with a slim, modiolar cochlear implant device. Hearing aid use in the contralateral ear was required through the 6-month primary end-point interval. Main Outcomes and Measures The primary objective was to evaluate speech perception before and 6 months after activation of a new cochlear implant. Secondary objectives were QoL metrics in the everyday listening condition before and 6 months after implantation. Results Seventy participants (51 men [73%]) with a median age of 74 (range, 65-91) years were included in the analysis. No major adverse events occurred. Mixed-model analysis with estimated marginal means and 95% CIs compared preimplantation baseline performance with 6-month postimplantation performance. A clinically important improvement in CNC words was shown in the bimodal condition, with a mean difference of 37.2% (95% CI, 32.0%-42.4%), and in the unilateral (cochlear implant only) condition, with a mean difference of 44.1% (95% CI, 39.0%-49.2%). A clinically important improvement in noise (AzBio sentences signal-to-noise ratio of +10 dB) was also shown, with a mean difference of 21.6% (95% CI, 15.7%-27.5%) in the bimodal condition and 24.5% (95% CI, 18.3%-30.7%) in the unilateral condition. The Health Utilities Index Mark 3 multiple-attribute score improved by 0.186 (95% CI, 0.136-0.234); the Speech, Spatial, and Qualities of Hearing Scale total score improved by 2.58 (95% CI, 2.18-2.99); and a novel Device Use Questionnaire reported 94% of participants were satisfied with overall hearing in the everyday listening condition. Conclusions and Relevance This subgroup analysis of patients 65 years or older enrolled in a within-subject clinical trial of cochlear implantation demonstrated clinically meaningful audiometric and QoL benefit with an acceptable risk profile. These findings suggest that cochlear implantation in older adults may facilitate the concept of healthy aging. Trial Registration ClinicalTrials.gov Identifier:NCT03007472

Binaural hearing allows listeners to take advantage of auditory cues that are necessary for sound localization. Patients with asymmetric or unilateral hearing loss receive degraded or absent binaural cues and often demonstrate decreased sound localization in the horizontal plane. Given the importance of sound localization for everyday function, there is a need for clinically feasible methods to evaluate localization, particularly as validation of intervention for patients with unilateral hearing loss. The present study compared sound localization results obtained for front-facing and rear-facing soundfield systems and for a rear-facing head related transfer function (HRTF) system in two hearing groups, listeners with normal hearing and those with unilateral hearing loss. Results between the three systems were highly correlated and repeatable. Neither age nor a pure-tone average of 0.5, 1, 2 and 4 kHz correlated with localization performance among normal hearing participants. Among the UHL group, age and onset of severe to profound hearing loss were positively correlated with localization results; length of deafness was negatively correlated. Behavioral chance performance was established for localization with rear-facing HRTF and rear-facing soundfield test systems; group mean results for unilateral hearing loss participants were significantly better than chance. Continued work is needed in developing clinically feasible evaluation methods for patients with asymmetric or unilateral hearing loss, particularly as the effects of treatment options are assessed.

Objectives A positive relation between audibility and speech understanding has been established for cochlear implant (CI) recipients. Sound field thresholds of 20 dB HL across the frequency range provide CI users the opportunity to understand soft and very soft speech. However, programming the sound processor to attain good audibility can be time-consuming and difficult for some patients. To address these issues, Advanced Bionics (AB) developed the SoftVoice algorithm designed to remove system noise and thereby improve audibility of soft speech. The present study aimed to evaluate the efficacy of SoftVoice in optimizing AB CI recipients' soft-speech perception. Design Two studies were conducted. Study 1 had two phases, 1A and 1B. Sixteen adult, AB CI recipients participated in Study 1A. Acute testing was performed in the unilateral CI condition using a Harmony processor programmed with participants' everyday-use program (Everyday) and that same program but with SoftVoice implemented. Speech recognition measures were administered at several presentation levels in quiet (35 to 60 dB SPL) and in noise (60 dB SPL). In Study 1B, 10 of the participants compared Everyday and SoftVoice at home to obtain feedback regarding the use of SoftVoice in various environments. During Study 2, soft-speech perception was acutely measured with Everyday and SoftVoice for 10 participants using the Naida CI Q70 processor. Results with the Harmony (Study 1A) and Naida processors were compared. Additionally, Study 2 evaluated programming options for setting electrode threshold levels (T-levels or Ts) to improve the usability of SoftVoice in daily life. Results Study 1A showed significantly higher scores with SoftVoice than Everyday at soft presentation levels (35, 40, 45, and 50 dB SPL) and no significant differences between programs at a conversational level (60 dB SPL) in quiet or in noise. After take-home experience with SoftVoice and Everyday (Study 1B), 5 of 10 participants reported preferring SoftVoice over Everyday; however, 6 reported bothersome environmental sound when listening with SoftVoice at home. Results of Study 2 indicated similar soft-speech perception between Harmony and Naida processors. Additionally, implementing SoftVoice with Ts at the manufacturer's default setting of 10% of Ms reduced reports of bothersome environmental sound during take-home experience; however, soft-speech perception was best with SoftVoice when Ts were behaviorally set above 10% of Ms. Conclusions Results indicate that SoftVoice may be a potential tool for optimizing AB users' audibility and, in turn, soft-speech perception. To achieve optimal performance at soft levels and comfortable use in daily environments, setting Ts must be considered with SoftVoice. Future research should examine program parameters that may benefit soft-speech perception when used in combination with SoftVoice (e.g., increased input dynamic range).

Objectives Asymmetric hearing with severe to profound hearing loss (SPHL) in one ear and better hearing in the other requires increased listening effort and is detrimental for understanding speech in noise and sound localization. Although a cochlear implant (CI) is the only treatment that can restore hearing to an ear with SPHL, current candidacy criteria often disallows this option for patients with asymmetric hearing. The present study aimed to evaluate longitudinal performance outcomes in a relatively large group of adults with asymmetric hearing who received a CI in the poor ear. Design Forty-seven adults with postlingual hearing loss participated. Test materials included objective and subjective measures meant to elucidate communication challenges encountered by those with asymmetric hearing. Test intervals included preimplant and 6 and 12 months postimplant. Preimplant testing was completed in participants' everyday listening condition: bilateral hearing aids (HAs) n = 9, better ear HA n = 29, and no HA n = 9; postimplant, each ear was tested separately and in the bimodal condition. Results Group mean longitudinal results in the bimodal condition postimplant compared with the preimplant everyday listening condition indicated significantly improved sentence scores at soft levels and in noise, improved localization, and higher ratings of communication function by 6 months postimplant. Group mean, 6-month postimplant results were significantly better in the bimodal condition compared with either ear alone. Audibility and speech recognition for the poor ear alone improved significantly with a CI compared with preimplant. Most participants had clinically meaningful benefit on most measures. Contributory factors reported for traditional CI candidates also impacted results for this population. In general, older participants had poorer bimodal speech recognition in noise and localization abilities than younger participants. Participants with early SPHL onset had better bimodal localization than those with later SPHL onset, and participants with longer SPHL duration had poorer CI alone speech understanding in noise but not in quiet. Better ear pure-tone average (PTA) correlated with all speech recognition measures in the bimodal condition. To understand the impact of better ear hearing on bimodal performance, participants were grouped by better ear PTA: group 1 PTA ≤40 dB HL (n = 19), group 2 PTA = 41 to 55 dB HL (n = 14), and group 3 PTA = 56 to 70 dB HL (n = 14). All groups showed bimodal benefit on speech recognition measures in quiet and in noise; however, only group 3 obtained benefit when noise was toward the CI ear. All groups showed improved localization and ratings of perceived communication. Conclusions Receiving a CI for the poor ear was an effective treatment for this population. Improved audibility and speech recognition were evident by 6 months postimplant. Improvements in sound localization and self-reports of communication benefit were significant and not related to better ear hearing. Participants with more hearing in the better ear (group 1) showed less bimodal benefit but greater bimodal performance for speech recognition than groups 2 and 3. Test batteries for this population should include quality of life measures, sound localization, and adaptive speech recognition measures with spatially separated noise to capture the hearing loss deficits and treatment benefits reported by this patient population.

To identify primary biographic and audiologic factors contributing to cochlear implant (CI) performance variability in quiet and noise by controlling electrode array type and electrode position within the cochlea.Although CI outcomes have improved over time, considerable outcome variability still exists. Biographic, audiologic, and device-related factors have been shown to influence performance. Examining CI recipients with consistent array type and electrode position may allow focused investigation into outcome variability resulting from biographic and audiologic factors.Thirty-nine adults (40 ears) implanted for at least 6 months with a perimodiolar electrode array known (via computed tomography [CT] imaging) to be in scala tympani participated. Test materials, administered CI only, included monosyllabic words, sentences in quiet and noise, and spectral ripple discrimination.In quiet, scores were high with mean word and sentence scores of 76 and 87%, respectively; however, sentence scores decreased by an average of 35 percentage points when noise was added. A principal components (PC) analysis of biographic and audiologic factors found three distinct factors, PC1 Age, PC2 Duration, and PC3 Pre-op Hearing. PC1 Age was the only factor that correlated, albeit modestly, with speech recognition in quiet and noise. Spectral ripple discrimination strongly correlated with speech measures.For these recipients with consistent electrode position, PC1 Age was related to speech recognition performance. Consistent electrode position may have contributed to high speech understanding in quiet. Inter-subject variability in noise may have been influenced by auditory/cognitive processing, known to decline with age, and mechanisms that underlie spectral resolution ability.

Adults with unilateral hearing loss often demonstrate decreased sound localization ability and report that situations requiring spatial hearing are especially challenging. Few studies have evaluated localization abilities combined with training in this population. The present pilot study examined whether localization of two sound types would improve after training, and explored the relation between localization ability or training benefit and demographic factors. Eleven participants with unilateral severe to profound hearing loss attended five training sessions; localization cues gradually decreased across sessions. Localization ability was assessed pre- and post-training. Assessment stimuli were monosyllabic words and spectral and temporal random spectrogram sounds. Root mean square errors for each participant and stimulus type were used in group and correlation analyses; individual data were examined with ordinary least squares regression. Mean pre- to post-training test results were significantly different for all stimulus types. Among the participants, eight significantly improved following training on at least one localization measure, whereas three did not. Participants with the poorest localization ability improved the most and likewise, those with the best pre-training ability showed the least training benefit. Correlation results suggested that test age, age at onset of severe to profound hearing loss and better ear high frequency audibility may contribute to localization ability. Results support the need for continued investigation of localization training efficacy and consideration of localization training within rehabilitation protocols for individuals with unilateral severe to profound hearing loss.

Purpose The purpose of this study was to examine the rate of progress in the 2nd implanted ear as it relates to the 1st implanted ear and to bilateral performance in adult sequential cochlear implant recipients. In addition, this study aimed to identify factors that contribute to patient outcomes. Method The authors performed a prospective longitudinal study in 21 adults who received bilateral sequential cochlear implants. Testing occurred at 6 intervals: prebilateral through 12 months postbilateral implantation. Measures evaluated speech recognition in quiet and noise, localization, and perceived benefit. Results Second ear performance was similar to 1st ear performance by 6 months postbilateral implantation. Bilateral performance was generally superior to either ear alone; however, participants with shorter 2nd ear length of deafness (30 years). All participants reported bilateral benefit. Conclusions Adult cochlear implant recipients demonstrated benefit from 2nd ear implantation for speech recognition, localization, and perceived communication function. Because performance outcomes were related to length of deafness, shorter time between surgeries may be warranted to reduce negative length-of-deafness effects. Future study may clarify the impact of other variables, such as preimplant hearing aid use, particularly for individuals with longer periods of deafness.

Objective A great deal of variability exists in the speech-recognition abilities of postlingually deaf adult cochlear implant (CI) recipients. A number of previous studies have shown that duration of deafness is a primary factor affecting CI outcomes; however, there is little agreement regarding other factors that may affect performance. The objective of the present study was to determine the source of variability in CI outcomes by examining three main factors, biographic/audiologic information, electrode position within the cochlea, and cognitive abilities in a group of newly implanted CI recipients. Design Participants were 114 postlingually deaf adults with either the Cochlear or Advanced Bionics CI systems. Biographic/audiologic information, aided sentence-recognition scores, a high resolution temporal bone CT scan and cognitive measures were obtained before implantation. Monosyllabic word recognition scores were obtained during numerous test intervals from 2 weeks to 2 years after initial activation of the CI. Electrode position within the cochlea was determined by three-dimensional reconstruction of pre- and postimplant CT scans. Participants' word scores over 2 years were fit with a logistic curve to predict word score as a function of time and to highlight 4-word recognition metrics (CNC initial score, CNC final score, rise time to 90% of CNC final score, and CNC difference score). Results Participants were divided into six outcome groups based on the percentile ranking of their CNC final score, that is, participants in the bottom 10% were in group 1; those in the top 10% were in group 6. Across outcome groups, significant relationships from low to high performance were identified. Biographic/audiologic factors of age at implantation, duration of hearing loss, duration of hearing aid use, and duration of severe-to-profound hearing loss were significantly and inversely related to performance as were frequency modulated tone, sound-field threshold levels obtained with the CI. That is, the higher-performing outcome groups were younger in age at the time of implantation, had shorter duration of severe-to-profound hearing loss, and had lower CI sound-field threshold levels. Significant inverse relationships across outcome groups were also observed for electrode position, specifically the percentage of electrodes in scala vestibuli as opposed to scala tympani and depth of insertion of the electrode array. In addition, positioning of electrode arrays closer to the modiolar wall was positively correlated with outcome. Cognitive ability was significantly and positively related to outcome; however, age at implantation and cognition were highly correlated. After controlling for age, cognition was no longer a factor affecting outcomes. Conclusion There are a number of factors that limit CI outcomes. They can act singularly or collectively to restrict an individual's performance and to varying degrees. The highest performing CI recipients are those with the least number of limiting factors. Knowledge of when and how these factors affect performance can favorably influence counseling, device fitting, and rehabilitation for individual patients and can contribute to improved device design and application.

Objectives At a minimum, unilateral hearing loss (UHL) impairs sound localization ability and understanding speech in noisy environments, particularly if the loss is severe to profound. Accompanying the numerous negative consequences of UHL is considerable unexplained individual variability in the magnitude of its effects. Identification of covariables that affect outcome and contribute to variability in UHLs could augment counseling, treatment options, and rehabilitation. Cochlear implantation as a treatment for UHL is on the rise yet little is known about factors that could impact performance or whether there is a group at risk for poor cochlear implant outcomes when hearing is near-normal in one ear. The overall goal of our research is to investigate the range and source of variability in speech recognition in noise and localization among individuals with severe to profound UHL and thereby help determine factors relevant to decisions regarding cochlear implantation in this population. Design The present study evaluated adults with severe to profound UHL and adults with bilateral normal hearing. Measures included adaptive sentence understanding in diffuse restaurant noise, localization, roving-source speech recognition (words from 1 of 15 speakers in a 140° arc), and an adaptive speech-reception threshold psychoacoustic task with varied noise types and noise-source locations. There were three age-sex-matched groups: UHL (severe to profound hearing loss in one ear and normal hearing in the contralateral ear), normal hearing listening bilaterally, and normal hearing listening unilaterally. Results Although the normal-hearing-bilateral group scored significantly better and had less performance variability than UHLs on all measures, some UHL participants scored within the range of the normal-hearing-bilateral group on all measures. The normal-hearing participants listening unilaterally had better monosyllabic word understanding than UHLs for words presented on the blocked/deaf side but not the open/hearing side. In contrast, UHLs localized better than the normal-hearing unilateral listeners for stimuli on the open/hearing side but not the blocked/deaf side. This suggests that UHLs had learned strategies for improved localization on the side of the intact ear. The UHL and unilateral normal-hearing participant groups were not significantly different for speech in noise measures. UHL participants with childhood rather than recent hearing loss onset localized significantly better; however, these two groups did not differ for speech recognition in noise. Age at onset in UHL adults appears to affect localization ability differently than understanding speech in noise. Hearing thresholds were significantly correlated with speech recognition for UHL participants but not the other two groups. Conclusions Auditory abilities of UHLs varied widely and could be explained only in part by hearing threshold levels. Age at onset and length of hearing loss influenced performance on some, but not all measures. Results support the need for a revised and diverse set of clinical measures, including sound localization, understanding speech in varied environments, and careful consideration of functional abilities as individuals with severe to profound UHL are being considered potential cochlear implant candidates.

The present study evaluated longitudinal performance outcomes in adult cochlear implant recipients with substantial hearing in the contralateral ear (mean better-ear PTA of 23.7 dB HL; range 0–40 dB HL). Of the 19 participants, 10 used a better-ear (BE) hearing aid both pre- and post-implant. Test intervals included pre-implant, 6 and 12 months post-implant. Participants’ everyday listening condition was primarily a single hearing ear pre-implant and bimodal (CI + BE) post-implant. Results indicated significant improvement over time in the everyday listening condition for sentences at a soft presentation level, sentences in noise (either surrounding or toward the BE), and localization. Self-reported communication ability also improved significantly over time. Group mean CNC word scores for the implanted ear alone improved significantly pre- to post-implant. Ear conditions were compared at the 6-month post-implant test interval. The same measures that demonstrated improvement over time in the everyday list...

The objective of this study was to evaluate the effect of the increased instantaneous input dynamic range (IIDR) in the Nucleus Freedom cochlear implant (CI) system on recipients' ability to perceive soft speech and speech in noise. Ten adult Freedom CI recipients participated. Two maps differing in IIDR were placed on each subject's processor at initial activation. The IIDR was set to 30 dB for one map and 40 dB for the other. Subjects used both maps for at least one month prior to speech perception testing. Results revealed significantly higher scores for words (50 dB SPL), for sentences in background babble (65 dB SPL), and significantly lower sound field threshold levels with the 40 compared to the 30 dB IIDR map. Ceiling effects may have contributed to non-significant findings for sentences in quiet (50 dB SPL). The Freedom's increased IIDR allows better perception of soft speech and speech in noise. El objetivo de este estudio fue evaluar el efecto del rango dinámico aumentado instantáneo de ingreso (IIDR) en el sistema de implante coclear (IC) Nucleus Freedom, sobre la capacidad de sujetos implantados para percibir lenguaje a bajo volumen y lenguaje en ruido. Diez sujetos implantados con el IC Freedom participaron. En la activación inicial, dos mapas con una diferencia en cuanto al IIDR se colocaron en el procesador de cada sujeto. El IIDR fue ajustado a 30 dB para un mapa y a 40 dB para el otro. Los sujetos utilizaron ambos mapas por al menos un mes, antes de una evaluación de percepción del lenguaje. Los resultados revelaron puntajes significativamente más altos para palabras (50 dB SPL), para frases en balbuceo de fondo (65 dB SPL), y niveles umbrales en campo libre significativamente más bajos con el mapa de IIDR de 40 comparado con el de 30. Efectos tope pueden haber contribuido a los hallazgos no significativos para frases en silencio (50 dB SPL). El IIDR aumentado para Freedom permite mejor percepción para el lenguaje a bajo volumen y el lenguaje en medio de ruido.

The effect on speech perception of using higher stimulation rates than the 14.4 kHz available in the Nucleus 24 cochlear implant system was investigated. The study used the Nucleus Research Platform 8 (RP8) system, comprising the CI24RE receiver-stimulator with the Contour electrode array, the L34SP body-worn research speech processor, and the Nucleus Programming Environment (NPE) fitting and Neural Response Telemetry (NRT) software. This system enabled clinical investigation of higher stimulation rates before an implementation in the Freedom cochlear implant system commercially released by Cochlear Limited.Use of higher stimulation rates in the ACE coding strategy was assessed in 15 adult subjects. An ABAB experimental design was used to control for order effects. Program A used a total stimulation rate of between 12 kHz and 14.4 kHz. This program was used for at least the first 3 mo after initial device activation. After evaluation with this program, each subject was provided with two different higher stimulation rate programs: one with a total stimulation rate of 24 kHz and the other with a total stimulation rate of 32 kHz. After a 6-week period of familiarization, each subject identified his/her preferred higher rate program (program B), and this was used for the evaluation. Subjects then repeated their use of program A for 3 wk, then program B for 3 wk, before the second evaluation with each. Speech perception was evaluated by using CNC open-set monosyllabic words presented in quiet and CUNY open-set sentences presented in noise. Preference for stimulation rate program was assessed via a subjective questionnaire. Threshold (T)- and Comfortable (C)-levels, as well as subjective reports of tinnitus, were monitored for each subject throughout the study to determine whether there were any changes that might be associated with the use of higher stimulation rates.No significant mean differences in speech perception results were found for the group between the two programs for tests in either quiet or noise. Analysis of individual subject data showed that five subjects had significant benefit from use of program B for tests administered in quiet and for tests administered in noise. However, only two of these subjects showed benefit in both test conditions. One subject showed significant benefit from use of program A when tested in quiet, whereas another showed benefit with this program in noise. Each subject's preferred program varied. Five subjects reported a preference for program A, eight subjects reported a preference for program B and two reported no overall preference. Preference between the different stimulation rates provided within program B also varied, with 10 subjects preferring 24 kHz and five preferring 32 kHz total stimulation rates. A significant increase in T-levels from baseline measures was observed after three weeks of initial experience with program B, however there was no difference between the baseline levels and those obtained after five weeks of use. No significant change in C-levels was found over the monitoring period. No long-term changes in tinnitus that could be associated with the use of the higher stimulation rates were reported by any of the subjects.The use of higher stimulation rates may provide benefit to some but not all cochlear implant recipients. It is important to optimize the stimulation rate for an individual to ensure maximal benefit. The absence of any changes in T- and C-levels or in tinnitus suggests that higher stimulation rates are safe for clinical use.

Two speech processor programs (MAPs) differing only in electrode frequency boundary assignments were created for each of eight Nucleus 24 Cochlear Implant recipients. The default MAPs used typical frequency boundaries, and the experimental MAPs reassigned one additional electrode to vowel formant regions. Four objective speech tests and a questionnaire were used to evaluate speech recognition with the two MAPs.Results for the closed-set vowel test and the formant discrimination test showed small but significant improvement in scores with the experimental MAP. Differences for the Consonant-Vowel Nucleus-Consonant word test and closed-set consonant test were nonsignificant. Feature analysis revealed no significant differences in information transmission. Seven of the eight subjects preferred the experimental MAP, reporting louder, crisper, and clearer sound.The results suggest that Nucleus 24 recipients should be given an opportunity to compare a MAP that assigns more electrodes in vowel formant regions with the default MAP to determine which provides the most benefit in everyday life.

Cochlear implant recipients often have limited access to lower level speech sounds. In this study we evaluated the effects of varying the input range characteristics of the Nucleus 24 cochlear implant system on recognition of vowels, consonants, and sentences in noise and on listening in everyday life.Twelve subjects participated in the study that was divided into two parts. In Part 1 subjects used speech processor (Nucleus 24 SPrint trade mark ) programs adjusted for three input sensitivity settings: a standard or default microphone sensitivity setting (MS 8), a setting that increased the input sensitivity by 10.5 dB (MS 15), and the same setting that increased input sensitivity but also incorporated the automatic sensitivity control (ASC; i.e., MS 15A) that is designed to reduce the loudness of noise. The default instantaneous input dynamic range (IIDR) of 30 dB was used in these programs (i.e., base level of 4; BL 4). Subjects were tested using each sensitivity program with vowels and consonants presented at very low to casual conversational levels of 40 dB SPL and 55 dB SPL, respectively. They were also tested with sentences presented at a raised level of 65 dB SPL in multi-talker babble at individually determined signal to noise ratios. In addition, subjects were given experience outside of the laboratory for several weeks. They were asked to complete a questionnaire where they compared the programs in different listening situations as well as the loudness of environmental sounds, and state the setting they preferred overall. In Part 2 of the study, subjects used two programs. The first program was their preferred sensitivity program from Part 1 that had an IIDR of 30 dB (BL 4). Seven subjects used MS 8 and four used MS 15, and one used the noise reduction program MS 15A. The second program used the same microphone sensitivity but had the IIDR extended by an additional 8 to 10 dB (BL 1/0). These two programs were evaluated similarly in the speech laboratory and with take-home experience as in Part 1. RESULTS PART 1: Increasing the microphone input sensitivity by 10.5 dB (from MS 8 to MS 15) significantly improved the perception of vowels and consonants at 40 and 55 dB SPL. The group mean improvement in vowel scores was 25 percentage points at 40 dB SPL and 4 percentage points at 55 dB SPL. The group mean improvement for consonants was 23 percentage points at 40 dB SPL and 11 percentage points at 55 dB SPL. Increased input sensitivity did not significantly reduce the perception of sentences presented at 65 dB SPL in babble despite the fact that speech peaks were then within the compressed range above the SPrint processor's automatic gain control (AGC) knee-point. Although there was a demonstrable advantage for perception of low-level speech with the higher input sensitivity (MS 15 and 15A), seven of the 12 subjects preferred MS 8, four preferred MS 15 or 15A, and one had no preference overall. Approximately half the subjects preferred MS 8 across the 18 listening situations, whereas an average of two subjects preferred MS 15 or 15A. The increased microphone sensitivity of MS 15 substantially increased the loudness of environmental sounds. However, use of the ASC noise reduction setting with MS 15 reduced the loudness of environmental sounds to equal or below that for MS 8. RESULTS PART 2: The increased instantaneous input range gave some improvement (8 to 9 percentage points for the 40 dB SPL presentation level) in the perception of consonants. There was no statistically significant increase in vowel scores. Mean scores for sentences presented at 65 dB SPL in babble were significantly lower (5 percentage points) for the increased IIDR setting. Subjects had no preference for the increased IIDR over the default. The IIDR setting had no effect on the loudness of environmental sounds.Given the fact that individuals differ in threshold (T) and comfort (C) levels for electrical stimulation, and preferred microphone sensitivity, volume control, and noise-reduction settings, it is essential for the clinicid recipient to determine what combination is best for the individual over several sessions. The results of this study clearly show the advantage of using higher microphone sensitivity settings than the default MS 8 to provide better speech recognition for low-level stimuli. However, it was also necessary to adjust other parameters such as map C levels, automatic sensitivity control and base level, to optimize loudness comfort in the diversity of listening situations an individual encounters in everyday life.

OBJECTIVE The primary objective of the study was to determine whether individual cochlear implant recipients recognize speech better with an electrical stimulation rate of 720 or 1800 pulses per second per channel (pps/ch) using the Nucleus 24 Advanced Combination Encoder (ACE) speech coding strategy. The secondary objective was to determine, for each active electrode, the relation between psychophysical measures and MAP minimum and maximum stimulation levels for each rate, as well as the stability of MAP minimum and maximum levels during the study. DESIGN Eight postlinguistically deaf adults implanted with the Nucleus 24 device participated in this study comparing the effect of a moderate (720 pps/ch) and a fast (1800 pps/ch) rate of electrical stimulation on speech recognition of words in quiet and sentences in noise presented at 50, 60, and 70 dB SPL in the laboratory and on listening to sound in everyday life over a 14-wk time period. At the beginning of the study, psychophysical measures (i.e., counted threshold and maximum acceptable loudness [MAL] levels) were obtained for each active electrode with each of the two rates to initially set MAP minimum and maximum stimulation levels. These levels were then adjusted to make speech and environmental sound clear and comfortable in everyday life. Threshold and MAL levels were obtained again half way through the study to monitor possible hearing changes. A four-phase test design for evaluation of speech recognition was followed; an equal number of subjects started with each of the two rates and alternated rates for each phase. In the last 2 wk of each phase, word and sentence scores were obtained, and subjects responded to a questionnaire. For the group, factorial analyses of variance were conducted for subject, stimulation rate, and time period (first two phases versus second two phases) for words, phonemes within words, and sentences at each level. Additional analyses were obtained for individual subjects. RESULTS Group mean scores across time periods were significantly higher for 1800 pps/ch than 720 pps/ch for phonemes and sentences in noise at 50 dB SPL. There was no significant difference in scores for phonemes and sentences at 60 and 70 dB SPL or for words at any of the three levels. Group mean scores across stimulation rate were significantly higher during the second half than the first half of the study for words, phonemes, and sentences at 50 dB SPL. This result is consistent with subjects learning to recognize speech cues near threshold. A subject by rate interaction was seen for sentences at 70 dB SPL and for all three speech measures at 50 dB SPL. These interactions reflect the fact that two subjects performed significantly better with 720 pps/ch, whereas two other subjects performed significantly better with 1800 pps/ch. Responses to the questionnaire indicated that two subjects preferred 720 pps/ch, three preferred 1800 pps/ch, and three had no preference. The minimum and/or maximum levels in most subjects' final MAPs differed from the psychophysical measures for both rates. Changes in Current Level at threshold and MAL were minimal from the first to the second half of the study for each rate. CONCLUSIONS More than half the subjects preferred one of the two rates for use in everyday life, and four subjects performed significantly better with one of the two rates on at least one test measure. These findings underscore the clinical importance of creating MAPs for each implant recipient that include at least a moderate and a fast rate within ACE during the first months of device use. Given the significant learning effects for soft speech that occurred over several weeks use of each rate in this study, it is suggested that each rate be used alone for a week or two before comparing them and deciding which provides more benefit. In addition, adjustments in an individual's MAP minimum and maximum levels are needed at each rate so soft and normal conversational speech as well as loud sound are clear and comfortable in everyday life.

Clinically, speech processor programs are created using electrical thresholds and maximum acceptable loudness levels (MALs) at several different stimulation rates to determine what rate will provide cochlear implant recipients with the best speech recognition when using fast-rate speech coding strategies. This study was designed to determine the difference in thresholds and MALs (expressed in the clinical unit, Current Level [CL]) for pairs of six rates spanning those available with the Nucleus 24 device (i.e., 250 to 2400 pps/ch) using monopolar, 25 μsec/phase stimulation. Test-retest measures of threshold and MAL for each rate were obtained from seven adult Nucleus 24 recipients on each of 11 electrodes. The difference in threshold and in MAL between pairs of rates was dependent on the absolute CL. Below approximately 190 CL, thresholds and MALs decreased with increasing rate; above 210 CL, there was little change in threshold or MAL with increasing rate. Based on these findings, an approach to estimating threshold and MAL from one rate to another is suggested, pending further research. Abbreviations: ACE = advanced combination encoder, CIS = continuous interleaved sampling, CT = computed tomography, CL = current level, FDA = U.S. Food and Drug Administration, MALs = maximum acceptable loudness levels, NRT = neural response telemetry, pps/ch = pulses per second per channel, SPEAK = spectral peak speech coding strategy, WinDPS = Windows programming and diagnostic system

Minimum stimulation levels for active electrodes in a Nucleus 22 cochlear implant were set at threshold (clinical default value) and raised levels ( M =+2.04 dB) to determine if raised levels would improve recipients' understanding of soft speech sounds with the SPEAK speech coding strategy. Eight postlinguistically deaf adults participated in a 4-phase A 1 B 1 A 2 B 2 , test design. Speech recognition was evaluated with consonant-vowel nucleus-consonant (CNC) words in quiet and sentences in noise, both presented at 50, 60, and 70 dB SPL during 2 weekly sessions at the end of each phase. Group mean scores were significantly higher with the raised level program for words and phonemes at 50 and 60 dB SPL and for sentences at 50 and 70 dB SPL. All participants chose to use the raised level program in everyday life at the end of the study. The results suggest that clinical use of a raised level program for Nucleus 22 recipients has the potential to make soft sounds louder and, therefore, more salient in everyday life. Further research is needed to determine if this approach is appropriate for other cochlear implant devices.

Ten postlinguistically deaf adults who used the Nucleus Cochlear Implant System and SPEAK speech coding strategy responded to vowels, consonants, words, and sentences presented sound-only at 70, 60, and 50 dB sound-pressure level. Highest group mean scores were at a raised-to-loud level of 70 dB for consonants (73%), words (44%), and sentences (87%); the highest score for vowels (70%) was at a conversational level of 60 dB. Lowest group mean scores were at a soft level of 50 dB for vowels (56%), consonants (47%), words (10%), and sentences (29%); all except subject 7 had some open-set speech recognition at this level. For the conversational level (60 dB), group mean scores for sentences and words were 72% and 29%, respectively. With this performance and sound-pressure level, it was observed that these subjects communicated successfully in a variety of listening situations. Given these subjects' speech recognition scores at 60 dB and the fact that 70 dB does not simulate the vocal effort used in everyday speaking situations, it is suggested that cochlear implant candidates and implantees be evaluated with speech tests presented at 60 dB instead of the customary 70 dB sound-pressure level to simulate benefit provided by implants in everyday life. Analysis of individuals' scores at the three levels for the four speech materials revealed different patterns of speech recognition among subjects (e.g., subjects 1 and 5). Future research on the relation between stimuli, sound processing, and subjects' responses associated with these different patterns may provide guidelines to select parameter values with which to map incoming sound onto an individual's electrical dynamic range between threshold and maximum acceptable loudness level to improve speech recognition.

The Spectra 22 Speech Processor and spectral peak (SPEAK) speech-coding strategy provide Nucleus 22 Channel Cochlear Implant (Cochlear, Corp., Englewood, Colo.) users with a better understanding of speech than the previous Mini Speech Processor and Multipeak (MPEAK) speech-coding strategy. On the NU-6 Monosyllabic Word Test, subjects scored 13% higher for words and 14% higher for phonemes with the SPEAK strategy than with the MPEAK strategy. On the Connected Speech Test and the CID Everyday Sentence Test, subjects scored 32% and 37% higher, respectively, with SPEAK than with MPEAK.

Seven subjects participated in a comparison of the normal ( N ) and noise suppression ( S ) settings on the Spectra 22 speech processor of the Nucleus TM 22-channel cochlear implant system. Speech recognition performance on the Consonant-Vowel Nucleus-Consonant (CNC) Word Test presented in quiet and on the CUNY Sentence Test presented at two signal-to-babble ratios (SBRs) was analyzed for both settings. Group data revealed no significant difference in performance between the N and S settings for either monosyllabic words in quiet or sentences presented in background babble.

Eight subjects participated in a comparison of the multipeak (MPEAK) and spectral peak (SPEAK) speech coding strategies of the Nucleus TM 22-channel cochlear implant system as part of a long-term monitoring study. Sound-field threshold levels and speech recognition performance on the Bamford-Kowal-Bench Sentence Test, NU-6 Monosyllabic Word Test, and Connected Speech Test or CID Everyday Sentence Test were analyzed for the two speech coding strategies. For the group, speech recognition performance was significantly higher with the SPEAK speech coding strategy than with the MPEAK strategy on all speech tests. For individual subjects, scores with the SPEAK strategy were significantly higher for some subjects on each of the speech tests. None of the subjects scored significantly higher on any of the tests with MPEAK.

Two stimulus paradigms and two presentation methods were combined to form three procedures (keyboard, knob, and ascending loudness judgments with knob [ALJK]) to obtain detection thresholds and maximum acceptable loudness tevels (MALs) from 11 adults with the Nucleus cochlear implant. Thresholds at which subjects correctly counted the number of stimulus bursts also were obtained. Keyboard detection thresholds were higher (Scheffé, p = .01) than knob and ALJK detection thresholds. Counted thresholds were obtained most efficiently by using keyboard detection thresholds as the initial level for testing. Keyboard MALs were highest, knob MALs intermediate, and AUK MALs lowest (Scheffé, p = .001). MALs were obtained most efficiently with the ALJK procedure. Implications of these results for clinical practice are discussed.

Bilateral severe to profound sensorineural hearing loss is a standard criterion for cochlear implantation. Increasingly, patients are implanted in one ear and continue to use a hearing aid in the nonimplanted ear to improve abilities such as sound localization and speech understanding in noise. Patients with severe to profound hearing loss in one ear and a more moderate hearing loss in the other ear (i.e., asymmetric hearing) are not typically considered candidates for cochlear implantation. Amplification in the poorer ear is often unsuccessful because of limited benefit, restricting the patient to unilateral listening from the better ear alone. The purpose of this study was to determine whether patients with asymmetric hearing loss could benefit from cochlear implantation in the poorer ear with continued use of a hearing aid in the better ear.Ten adults with asymmetric hearing between ears participated. In the poorer ear, all participants met cochlear implant candidacy guidelines; seven had postlingual onset, and three had pre/perilingual onset of severe to profound hearing loss. All had open-set speech recognition in the better-hearing ear. Assessment measures included word and sentence recognition in quiet, sentence recognition in fixed noise (four-talker babble) and in diffuse restaurant noise using an adaptive procedure, localization of word stimuli, and a hearing handicap scale. Participants were evaluated preimplant with hearing aids and postimplant with the implant alone, the hearing aid alone in the better ear, and bimodally (the implant and hearing aid in combination). Postlingual participants were evaluated at 6 mo postimplant, and pre/perilingual participants were evaluated at 6 and 12 mo postimplant. Data analysis compared the following results: (1) the poorer-hearing ear preimplant (with hearing aid) and postimplant (with cochlear implant); (2) the device(s) used for everyday listening pre- and postimplant; and (3) the hearing aid-alone and bimodal listening conditions postimplant.The postlingual participants showed significant improvements in speech recognition after 6 mo cochlear implant use in the poorer ear. Five postlingual participants had a bimodal advantage over the hearing aid-alone condition on at least one test measure. On average, the postlingual participants had significantly improved localization with bimodal input compared with the hearing aid-alone. Only one pre/perilingual participant had open-set speech recognition with the cochlear implant. This participant had better hearing than the other two pre/perilingual participants in both the poorer and better ear. Localization abilities were not significantly different between the bimodal and hearing aid-alone conditions for the pre/perilingual participants. Mean hearing handicap ratings improved postimplant for all participants indicating perceived benefit in everyday life with the addition of the cochlear implant.Patients with asymmetric hearing loss who are not typical cochlear implant candidates can benefit from using a cochlear implant in the poorer ear with continued use of a hearing aid in the better ear. For this group of 10, the 7 postlingually deafened participants showed greater benefits with the cochlear implant than the pre/perilingual participants; however, further study is needed to determine maximum benefit for those with early onset of hearing loss.

Background: Current measures used to determine sentence recognition abilities in cochlear implant recipients often include tests with one talker and one rate of speech. Performance with these measures may not accurately represent the speech recognition abilities of the listeners. Evaluation of cochlear implant performance should include measures that reflect realistic listening conditions. For example, the use of multiple talkers who vary in gender, rate of speech, and regional dialects represent varied communication interactions that people encounter daily. The TIMIT sentences, which use multiple talkers and incorporate these variations, provide additional test material for evaluating speech recognition. Dorman and colleagues created 34 lists of TIMIT sentences that were normalized for equal intelligibility using simulations of cochlear implant processing with normal-hearing listeners. Adults with sensorineural hearing loss who listen with cochlear implants represent a different population. Further study is needed to determine if these lists are equivalent for adult cochlear implant recipients and, if not, to identify a subset of lists that may be used with this population. Purpose: To evaluate the speech recognition equivalence of 34 TIMIT sentence lists with adult cochlear implant recipients. Research Design: A prospective study comparing test-retest results within the same group of listeners. Study Sample: Twenty-two adult cochlear implant recipients who met the inclusion criteria of at least 3 mo device use and a monosyllabic word score of 30% or greater participated in the study. Data Collection and Analysis: Participants were administered 34 TIMIT sentence lists (20 sentences per list) at each of two test sessions several months apart. List order was randomized and results scored as percent of words correct. Test-retest correlations and 95% confidence intervals for the means were used to identify equivalent lists with high test-retest reliability. Results: Mean list scores across participants ranged from 66 to 81% with an overall mean of 73%. Twenty-nine lists had high test-retest reliability. Using the overall mean as a benchmark, the 95% confidence intervals indicated that 25 of the remaining 29 lists were equivalent (e.g., the benchmark of 73% fell within the 95% confidence interval for both test and retest). Conclusions: Twenty-five of the TIMIT lists evaluated are equivalent when used with adult cochlear implant recipients who have open-set word recognition abilities. These lists may prove valuable for monitoring progress, comparing listening conditions or treatments, and developing aural rehabilitation plans for cochlear implant recipients.

This case study describes a 45-yr-old female with bilateral, profound sensorineural hearing loss due to Ménière’s disease. She received her first cochlear implant in the right ear in 2008 and the second cochlear implant in the left ear in 2010. The case study examines the enhancement to speech recognition, particularly in noise, provided by bilateral cochlear implants.Speech recognition tests were administered prior to obtaining the second implant and at a number of test intervals following activation of the second device. Speech recognition in quiet and noise as well as localization abilities were assessed in several conditions to determine bilateral benefit and performance differences between ears. The results of the speech recognition testing indicated a substantial improvement in the patient’s ability to understand speech in noise and her ability to localize sound when using bilateral cochlear implants compared to using a unilateral implant or an implant and a hearing aid. In addition, the patient reported considerable improvement in her ability to communicate in daily life when using bilateral implants versus a unilateral implant.This case suggests that cochlear implantation is a viable option for patients who have lost their hearing to Ménière’s disease even when a number of medical treatments and surgical interventions have been performed to control vertigo. In the case presented, bilateral cochlear implantation was necessary for this patient to communicate successfully at home and at work.

This study aimed to provide guidelines to optimize perception of soft speech and speech in noise for Advanced Bionics cochlear implant (CI) users.Three programs differing in T-levels were created for ten subjects. Using the T-level setting that provided the lowest FM-tone, sound-field threshold levels for each subject, three additional programs were created with input dynamic range (IDR) settings of 50, 65 and 80 dB.Subjects were postlinguistically deaf adults implanted with either the Clarion CII or 90K CI devices.Sound-field threshold levels were lowest with T-levels set higher than 10% of M-levels and with the two widest IDRs. Group data revealed significantly higher scores for CNC words presented at a soft level with an IDR of 80 dB and 65 dB compared to 50 dB. Although no significant group differences were seen between the three IDRs for sentences in noise, significant individual differences were present.Setting Ts higher than the manufacturer's recommendation of 10% of M-levels and providing IDR options can improve overall speech perception; however, for some users, higher Ts and wider IDRs may not be appropriate. Based on the results of the study, clinical programming recommendations are provided.

This study investigates the effect of the Nucleus CI24RE implant's neural response telemetry (NRT) system, which has less internal noise compared to its predecessor, the CI24M/R implant, on the NRT threshold (TNRT) profile across the array. CI24M/R measurements were simulated by ignoring CI24RE measurements with response amplitudes below 50 uV. Comparisons of the estimated TNRTs from the CI24RE measurements and the CI24M/R simulations suggest that, apart from a constant level difference, the TNRT profiles from the newer implant generally would not have differed very much from those of its predecessor. This view was also reflected by principal component analysis (PCA) results which revealed a 'shift' component similar to that reported by Smoorenburg et al (2002). On the whole, there is no indication that current practices of using the TNRT profiles for assisting with speech processor programming need to be revised for the CI24RE implant.

HiRes (HR) 120 is a sound-processing strategy purported to offer an increase in the precision of frequency-to-place mapping through the use of current steering. This within-subject study was designed to compare speech recognition as well as music and sound quality ratings for HR and HR 120 processing.Cochlear implant/tertiary referral center.Eight postlinguistically deafened adults implanted with an Advanced Bionics CII or HR 90K cochlear implant. STUDY DESIGN/MAIN OUTCOME MEASURES: Performance with HR and HR 120 was assessed during 4 test sessions with a battery of measures including monosyllabic words, sentences in quiet and in noise, and ratings of sound quality and musical passages.Compared with HR, speech recognition results in adult cochlear implant recipients revealed small but significant improvements with HR 120 for single syllable words and for 2 of 3 sentence recognition measures in noise. Both easy and more difficult sentence material presented in quiet were not significantly different between strategies. Additionally, music quality ratings were significantly better for HR 120 than for HR, and 7 of 8 subjects preferred HR 120 over HR for listening in everyday life.HR 120 may offer equivalent or improved benefit to patients compared with HR. Differences in performance on test measures between strategies are dependent on speech recognition materials and listening conditions.

The choice of frequency boundaries for the analysis channels of cochlear implants has been shown to impact the speech perception performance of adult recipients (Skinner et al, 1995; Fourakis et al, 2004). While technological limitations heretofore have limited the clinical feasibility of investigating novel frequency assignments, the SPEAR3 research processor affords the opportunity to investigate an unlimited number of possibilities. Here, four different assignments are evaluated using a variety of speech stimuli. All participants accommodated to assignment changes, and no one assignment was significantly preferred. The results suggest that better performance can be achieved using a strategy whereby (1) there are at least 7-8 electrodes allocated below 1000 Hz, (2) the majority of remaining electrodes are allocated between 1100 - 3000 Hz, and (3) the region above 3 kHz is represented by relatively few electrodes (i.e., 1-3). The results suggest that such frequency assignment flexibility should be made clinically available. La escogencia de límites de frecuencia para los canales de análisis de los implantes cocleares se ha visto que impacta el desempeño en la percepción del lenguaje de adultos implantados (Skinner y col, 1995; Fourakis y col, 2004). Mientras que las limitaciones tecnológicas hasta este momento han restringido la factibilidad clínica de investigar nuevas asignaciones de frecuencia, el procesador experimental SPEAR3 ofrece la oportunidad de investigar un número ilimitado de posibilidades. Aquí, se evalúan cuatro asignaciones diferentes utilizando una variedad de estímulos de lenguaje. Todos los participantes se acomodaron a los cambios de asignación y ninguna asignación tuvo una preferencia significativa. Los resultados sugieren que puede obtenerse un desempeño mejor utilizando una estrategia donde (1) existan al menos 7-8 electrodos colocados por debajo de 1000 Hz, (2) la mayoría de los electrodos remanentes sean colocados entre 1100 – 3000 Hz, y (3) la región por encima de 3 kHz esté representada por relativamente pocos electrodos (p.e., 1-3). Los resultados sugieren que tal flexibilidad en la asignación de frecuencias debería estar clínicamente disponible.

Suboptimal cochlear implant (CI) electrode array placement may reduce presentation of coded information to the central nervous system and, consequently, limit speech recognition.Generally, mean speech reception scores for CI recipients are similar across different CI systems, yet large outcome variation is observed among recipients implanted with the same device. These observations suggest significant recipient-dependent factors influence speech reception performance. This study examines electrode array insertion depth and scalar placement as recipient-dependent factors affecting outcome.Scalar location and depth of insertion of intracochlear electrodes were measured in 14 patients implanted with Advanced Bionics electrode arrays and whose word recognition scores varied broadly. Electrode position was measured using computed tomographic images of the cochlea and correlated with stable monosyllabic word recognition scores.Electrode placement, primarily in terms of depth of insertion and scala tympani versus scala vestibuli location, varies widely across subjects. Lower outcome scores are associated with greater insertion depth and greater number of contacts being located in scala vestibuli. Three patterns of scalar placement are observed suggesting variability in insertion dynamics arising from surgical technique.A significant portion of variability in word recognition scores across a broad range of performance levels of CI subjects is explained by variability in scalar location and insertion depth of the electrode array. We suggest that this variability in electrode placement can be reduced and average speech reception improved by better selection of cochleostomy sites, revised insertion approaches, and control of insertion depth during surgical placement of the array.

Thirty "new" lists of monosyllabic words were created at the University of Melbourne and recorded by Australian and American English speakers. These new lists and the ten original CNC lists (Peterson and Lehiste, 1962) were used during the feasibility study of the Nucleus Research Platform 8 Cochlear Implant System (Holden et al, 2004). Performance was similar across original and new lists for six implanted Australian subjects; for four implanted U.S. subjects, mean performance was 23 percentage points lower with the new than with the original lists. To evaluate differences between original and new lists for the American English recording, 22 CI recipients were administered all 40 CNC lists (30 new and 10 original lists). The overall mean word score for the new lists was significantly lower (22.3 percentage points) than for the original lists. Acoustic analysis revealed that decreased performance was most likely due to reduced amplitudes of certain initial and final consonants. The new CNC lists can be used as more difficult test material for clinical research.

The purpose of this study was to conduct a large-scale investigation with adult recipients of the Clarion, Med-El, and Nucleus cochlear implant systems to (1) determine average scores and ranges of performance for word and sentence stimuli presented at three intensity levels (70, 60, and 50 dB SPL); (2) provide information on the variability of scores for each subject by obtaining test-retest measures for all test conditions; and (3) further evaluate the potential use of lower speech presentation levels (i.e., 60 and/or 50 dB SPL) in cochlear implant candidacy assessment.Seventy-eight adult cochlear implant recipients, 26 with each of the three cochlear implant systems, participated in the study. To ensure that the data collected reflect the range of performance of adult recipients using recent technology for the three implant systems (Clarion HiFocus I or II, Med-El Combi 40+, Nucleus 24M or 24R), a composite range and distribution of consonant-nucleus-consonant (CNC) monosyllabic word scores was determined. Subjects using each device were selected to closely represent this range and distribution of CNC performance. During test sessions, subjects were administered the Hearing in Noise Test (HINT) sentence test and the CNC word test at three presentation levels (70, 60, and 50 dB SPL). HINT sentences also were administered at 60 dB SPL with a signal-to-noise ratio (SNR) of +8 dB. Warble tones were used to determine sound-field threshold levels from 250 to 4000 Hz. Test-retest measures were obtained for each of the speech recognition tests as well as for warble-tone sound-field thresholds.Cochlear implant recipients using the Clarion, Med-El, or Nucleus devices performed on average equally as well at 60 compared with 70 dB SPL when listening for words and sentences. Additionally, subjects had substantial open-set speech perception performance at the softer level of 50 dB SPL for the same stimuli; however, subjects' ability to understand speech was poorer when listening in noise to signals of greater intensity (60 dB SPL + 8 SNR) than when listening to signals presented at a soft presentation level (50 dB SPL) in quiet. A significant correlation was found between sound-field thresholds and speech recognition scores for presentation levels below 70 dB SPL. The results demonstrated a high test-retest reliability with cochlear implant users for these presentation levels and stimuli. Average sound-field thresholds were between 24 and 29 dB HL for frequencies of 250 to 4000 Hz, and results across sessions were essentially the same.Speech perception measures used with cochlear implant candidates and recipients should reflect the listening challenges that individuals encounter in natural communication situations. These data provide the basis for recommending new candidacy criteria based on speech recognition tests presented at 60 and/or 50 dB SPL, intensity levels that reflect real-life listening, rather than 70 dB SPL.

One of the difficulties faced by cochlear implant (CI) recipients is perception of low-intensity speech cues. A. E. Vandali (2001) has developed the transient emphasis spectral maxima (TESM) strategy to amplify short-duration, low-level sounds. The aim of the present study was to determine whether speech scores would be significantly higher with TESM than with the advanced combination encoder (ACE) strategy fitted using procedures that optimize perception of soft speech and other sounds. Eight adult recipients of the Nucleus 24 CI system participated in this study. No significant differences in scores were seen between ACE and TESM for consonant-vowel nucleus-consonant (CNC) words presented at 55 and 65 dB SPL, for sentences in noise presented at 65 dB SPL at 2 different signal-to-noise ratios, or for closed-set vowels and consonants presented at 60 dB SPL. However, perception of stop consonants within CNC words presented at the lower level (55 dB SPL) was significantly higher with TESM than ACE. In addition, percentage of information transmitted for words at 55 dB SPL was significantly higher with TESM than with ACE for manner and voicing features for consonants in the initial word position. Analysis of closed-set consonants presented at 60 dB SPL revealed percentage of information transmitted for manner was significantly higher with TESM than with ACE. These improvements with TESM were small compared with those reported by Vandali for recipients of the Nucleus 22 CI system. It appears that mapping techniques used to program speech processors and improved processing capabilities of the Nucleus 24 system contributed to soft sounds being understood almost as well with ACE as with TESM. However, half of the participants preferred TESM to ACE for use in everyday life, and all but 1 used TESM in specific listening situations. Clinically, TESM may be useful to ensure the audibility of low-intensity, short-duration acoustic cues that are important for understanding speech, for recipients who are difficult to map, or if insufficient time precludes the use of mapping techniques to increase audibility of soft sound.

The objective of this study was to determine whether 1) the SPEAK, ACE or CIS speech coding strategy was associated with significantly better speech recognition for individual subjects implanted with the Nucleus CI24M internal device who used the SPrint speech processor, and 2) whether a subject's preferred strategy for use in everyday life provided the best speech recognition.Twelve postlinguistically deaf, newly implanted adults participated. Initial preference for the three strategies was obtained with paired-comparison testing on the first day of implant stimulation with seven of eight U.S. subjects. During the first 12 wk, all subjects used each strategy alone for 4 wk to give them experience with the strategy and to identify preferred speech processor program parameters and settings that would be used in subsequent testing. For the next 6 wk, subjects used one strategy at a time for 2-wk intervals in the same order they had for the first 12 wk. At the end of each 2-wk interval, speech recognition testing was conducted with all three strategies. At the end of the 6 wk, all three strategies were placed on each subject's processor, and subjects were asked to compare listening with these three programs in as many situations as possible for the next 2 wk. When they returned, subjects responded to a questionnaire asking about their preferred strategy and responded to two lists of medial consonants using each of the three strategies. The U.S. subjects also responded to two lists of medial vowels with the three strategies.Six of the 12 subjects in the present study had significantly higher CUNY sentence scores with the ACE strategy than with one or both of the other strategies; one of the 12 subjects had a significantly higher score with SPEAK than with ACE. In contrast, only two subjects had significantly higher CNC word and phoneme scores with one or two strategies than with the third strategy. One subject had a significantly higher vowel score with the SPEAK strategy than with the CIS strategy; and no subjects had significantly higher consonant scores with any strategy. Seven of 12 subjects preferred the ACE strategy, three preferred the SPEAK strategy, and two preferred the CIS strategy. Subjects' responses on a questionnaire agreed closely with strategy preference from comparisons made in everyday life. There was a strong relation between the preferred strategy and scores on CUNY sentences but not for the other speech tests. For all subjects, except one, the preferred strategy was the one with the highest CUNY sentence score or was a strategy with a CUNY score not significantly lower than the highest score.Despite differences in research design, there was remarkably close agreement in the pattern of group mean scores for the three strategies for CNC words and CUNY sentences in noise between the present study and the Conversion study (Arndt, Staller, Arcaroli, Hines,Ebinger, Reference Note 1). In addition, essentially the same percentage of subjects preferred each strategy. For both studies, the strategy with which subjects had the highest score on the CUNY sentences in noise evaluation was strongly related to the preferred strategy; this relation was not strong for CNC words, CNC phonemes, vowels or consonants (Skinner, Arndt,Staller, 2002). These results must be considered within the following context. For each strategy, programming parameters preferred for use in everyday life were determined before speech recognition was evaluated. In addition, implant recipients had experience listening with all three strategies in many situations in everyday life before choosing a preferred strategy. Finally, 11 of the 12 subjects strongly preferred one of the three strategies. Given the results and research design, it is recommended that clinicians fit each strategy sequentially starting with the ACE strategy so that the preferred programming parameters are determined for each strategy before recipients compare pairs of strategies. The goal is to provide the best opportunity for individuals to hear in everyday life within a clinically acceptable time period (e.g., 6 wk).

This study extended the findings of Ketten et al. [Ann. Otol. Rhinol. Laryngol. Suppl. 175:1-16 (1998)] by estimating the three-dimensional (3D) cochlear lengths, electrode array intracochlear insertion depths, and characteristic frequency ranges for 13 more Nucleus-22 implant recipients based on in vivo computed tomography (CT) scans. Array insertion depths were correlated with NU-6 word scores (obtained one year after SPEAK strategy use) by these patients and the 13 who used the SPEAK strategy from the Ketten et al. study. For these 26 patients, the range of cochlear lengths was 29.1-37.4 mm. Array insertion depth range was 11.9-25.9 mm, and array insertion depth estimated from the surgeon's report was 1.14 mm longer than CT-based estimates. Given the assumption that the human hearing range is fixed (20-20,000 Hz) regardless of cochlear length, characteristic frequencies at the most apical electrode (estimated with Greenwood's equation [Greenwood DD (1990) A cochlear frequency--position function of several species--29 years later. J Acoust. Soc. Am. 33: 1344-1356] and a patient-specific constant as) ranged from 308 to 3674 Hz. Patients' NU-6 word scores were significantly correlated with insertion depth as a percentage of total cochlear length (R = 0.452; r2 = 0.204; p = 0.020), suggesting that part of the variability in word recognition across implant recipients can be accounted for by the position of the electrode array in the cochlea. However, NU-6 scores ranged from 4% to 81% correct for patients with array insertion depths between 47% and 68% of total cochlear length. Lower scores appeared related to low spiral ganglion cell survival (e.g., lues), aberrant current paths that produced facial nerve stimulation by apical electrodes (i.e., otosclerosis), central auditory processing difficulty, below-average verbal abilities, and early Alzheimer's disease. Higher scores appeared related to patients' high-average to above-average verbal abilities. Because most patients' scores increased with SPEAK use, it is hypothesized that they accommodated to the shift in frequency of incoming sound to a higher pitch percept with the implant than would normally be perceived acoustically.

Objective The main objective was to investigate whether the broadening and narrowing of formant bandwidths had a significant effect on the identification of vowels often confused by Nucleus cochlear implant recipients using the Spectral Peak (SPEAK) speech coding strategy. Specifically, identification performance for synthetic vowels with the first two formants (F1 and F2) parametrically varied in bandwidth was explored. Design Eight implanted subjects identified synthetic versions of the isolated vowel sounds [I, epsilon, lambda, [symbol: see text]] with F1 and F2 bandwidth manipulations, as well as foil tokens of [i, u, a, ae, [symbol: see text]]. Identification performance was examined in terms of percent correct as well as error patterns. Further analyses compared patterns of electrode activation. Results In general, broader F1 bandwidths yielded poorer performance and narrower F1 bandwidths yielded better performance relative to identifications for the reference stimuli. However, similar manipulations of F2 bandwidths resulted in less predictable performance. Comparison of electrode activation patterns indicated a distinct sharpening or flattening in the F1 frequency region for subjects with the greatest performance extremes. Conclusions Manipulation of F1 bandwidth can result in concomitant changes in electrode activation patterns and identification performance. This suggests that modifications in the SPEAK coding strategy for the F1 region may be a consideration. Similar manipulations of F2 bandwidth yielded less predictable results and require further investigation.

Speech coding strategy, frequency boundary assignment table, and speech processor program minimum and maximum stimulation levels are parameters of the Nucleus Cochlear Implant System whose selection affects speech recognition performance in adults and children. Research studies show that speech recognition is significantly better with (1) the Spectral Peak than with the Multipeak speech coding strategy and (2) frequency boundary assignment Table 7 than with Table 9 in an individual's speech processor program (MAP). Minimum and maximum stimulation levels in this MAP are based on psychophysical measurements on each electrode but often need to be modified for optimum use in everyday life. Many children and adults have increases, decreases, or fluctuations in electrical hearing that require changes in the MAP minimum and maximum levels to maintain their ability to recognize speech and other sounds.

OBJECTIVE The major objective of this study was to evaluate differences in consonant recognition with the Multipeak (MPEAK) and the Spectral Peak (SPEAK) speech coding strategies of the Nucleus-22 Cochlear Implant System. This objective was addressed by comparison of acoustic and electrode activation analyses of consonants with cochlear implant recipients' responses to these same consonant tokens when they used the two speech coding strategies. DESIGN Nine subjects identified 14 English consonants with the MPEAK and SPEAK speech coding strategies. These strategies were compared with an ABAB design. Evaluation occurred during two weekly sessions after subjects used each strategy for at least 3 wk in everyday life. RESULTS Group medial consonant [aCa] identification scores with the SPEAK strategy were significantly higher than with the MPEAK strategy (76.2% versus 67.5%; p < 0.001). This improvement was largely due to the significant increase in information transmitted for the place feature (p < 0.001) through accurate tracking of second formant transitions and spectrally specific stimulation patterns to differentiate [s] from [symbol see text] and [n] from [m], and the stop consonant bursts. For this reason, more nasal consonants were correctly identified with SPEAK, but there also were more non-nasal error responses when the nasal murmur was of unusually low amplitude. Consequently, significantly less information was transmitted for the nasality feature with SPEAK than MPEAK (p < 0.001). CONCLUSIONS Electrical stimulation with the SPEAK strategy provided better spectral representation of the stop consonant bursts, tracking formant transitions into the following vowel, frication in the consonant [symbol see text], and the formants for the nasals [m] and [n] than with the MPEAK strategy. The marked improvement in recognition of the velar consonants, [g] and [k], which cannot be seen during speechreading, should allow greater ease and accuracy of communication with SPEAK than MPEAK.

Objective: This study was designed to evaluate performance stability with test-retest measures of electrical thresholds, electrical maximum acceptable loudness levels, sound-field thresholds, and audition-only speech tests. The hypothesis was that the standard error of measurement differs from one individual to another for each test, and therefore test-retest measures need to be obtained from each subject. Design: Test-retest data were obtained in three sets. For the first two sets, data were obtained over 4 successive weeks to determine day-to-day variability. The third set was obtained on 2 successive days, 2 to 10 months later at each subject's annual evaluation. The seven subjects were recipients of the Nucleus cochlear implant and used the Mini Speech Processor at least one year. They were selected because they were available for research testing. Results: The ranges of electrical thresholds and maximum acceptable loudness levels obtained from each subject during the first two sets were substantially larger on some electrodes than on others. Between set 1 and set 2 for each subject, there were significant differences between thresholds and between maximum acceptable loudness levels on some electrodes. For thresholds as well as maximum acceptable loudness levels, the standard error of measurement across the three sets and 10 electrodes differed among subjects. The group standard error of measurement for sound-field thresholds was small (2 dB). The group standard error of measurement for the NU-6 word test scored according to phonemes (2.75%) was less than half that for the vowel (6.06%) and consonant (5.67%) tests. The standard error of measurement for each speech test differed among subjects. Conclusions: The standard error of measurement for thresholds as well as maximum acceptable loudness levels varies among electrodes in the same subject and among subjects across electrodes. The standard error of measurement also varies among speech tests for the group as well as among subjects for each speech test. There is little variation in test-retest measures of sound-field thresholds among subjects. These results suggest the clinical importance of obtaining test-retest measures for evaluating the stability of electrical thresholds, electrical maximum acceptable loudness levels, and speech tests.

Seven postlinguistically deaf adults implanted with the Nucleus Multi-Electrode Cochlear Implant participated in an evaluation of speech perception performance with three speech processors: the Wearable Speech Process (WSP III), a prototype of the Mini Speech Processor, and the Mini Speech Processor. The first experiment was performed with the prototype and Wearable Speech Processor both programmed using the F0F1F2 speech coding strategy. The second experiment compared performance with the Mini Speech Processor programmed with the Multi-Peak speech coding strategy and the Wearable Speech Processor programmed with the F0F1F2 speech coding strategy. Performance was evaluated in the sound-only condition using recorded speech tests presented in quiet and in noise. Questionnaires and informal reports provided information about use in everyday life. In experiment I, there was no significant difference in performance using the Wearable Speech Processor and prototype on any of the tests. Nevertheless, six out of seven subjects preferred the prototype for use in everyday life. In experiment II, performance on open-set tests in quiet and noise was significantly higher with the Mini Speech Processor (Multi-Peak speech coding strategy) than with the Wearable Speech Processor. Subjects reported an increase in their ability to communicate with other people using the Mini Speech Processor (Multi-Peak speech coding strategy) compared with the Wearable Speech Processor in everyday life.

The aim of the experiment reported here was to examine the responses to synthetic vowels of the processor of the Nucleus Cochlear Implant System, using the MPEAK and SPEAK speech coding strategies. In previous work with natural vowels (Skinner et al., submitted to Ear Hear.), it was found that second formant information was better transmitted using the SPEAK strategy, while first formant information was better transmitted using the MPEAK strategy. Examination of the output of the SPEAK processor showed activation of multiple adjacent electrodes resulting in less distinct spectral cues than with MPEAK. This prompted the present investigation, which uses synthetic vowels with varying formant bandwidths. Four synthetic vowels, which had been identified consistently by normal hearing subjects as one of [I, e, U, inverted vee] were used as anchor points for the creation of continua in which the bandwidths of the first and second formants were systematically and independently decreased in steps of 10% to a mini...

Four postlinguistically deaf adults were evaluated presurgically with a one- or two-channel vibrotactile aid and postsurgically with a multichannel, multielectrode, intracochlear implant. Although the vibrotactile aid provided awareness of sound and enhanced flow of conversation, benefit to lipreading was small on videotaped tests and speech tracking. Scores on recorded, sound-only speech tests were not significantly above chance except in discrimination of noise from voice. With the cochlear implant, benefit to lipreading was significantly greater than with the vibrotactile aid, and scores on sound-only tests were significantly above chance. Communication was markedly better with the implant than with the vibrotactile aid. In counseling those who get no benefit from a hearing aid, the results of this study provide data on the amount of benefit one- or two-channel vibrotactile aids provide postlinguistically deaf adults who are subsequently implanted.