The Effect of Instantaneous Input Dynamic Range Setting on the Speech Perception of Children with the Nucleus 24 Implant

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.

Download Full-text

Intracochlear Position of Cochlear Implants Determined Using CT Scanning versus Fitting Levels: Higher Threshold Levels at Basal Turn

Audiology and Neurotology ◽

10.1159/000442513 ◽

2016 ◽

Vol 21 (1) ◽

pp. 54-67 ◽

Cited By ~ 8

Author(s):

Feddo B. van der Beek ◽

Jeroen J. Briaire ◽

Kim S. van der Marel ◽

Berit M. Verbist ◽

Johan H.M. Frijns

Keyword(s):

Speech Perception ◽

Cochlear Implants ◽

Dynamic Range ◽

Ct Scanning ◽

Electrode Position ◽

Insertion Depth ◽

Threshold Levels ◽

Lower Amplitude ◽

Standard Profile

Objectives: In this study, the effects of the intracochlear position of cochlear implants on the clinical fitting levels were analyzed. Design: A total of 130 adult subjects who used a CII/HiRes 90K cochlear implant with a HiFocus 1/1J electrode were included in the study. The insertion angle and the distance to the modiolus of each electrode contact were determined using high-resolution CT scanning. The threshold levels (T-levels) and maximum comfort levels (M-levels) at 1 year of follow-up were determined. The degree of speech perception of the subjects was evaluated during routine clinical follow-up. Results: The depths of insertion of all the electrode contacts were determined. The distance to the modiolus was significantly smaller at the basal and apical cochlear parts compared with that at the middle of the cochlea (p < 0.05). The T-levels increased toward the basal end of the cochlea (3.4 dB). Additionally, the M-levels, which were fitted in our clinic using a standard profile, also increased toward the basal end, although with a lower amplitude (1.3 dB). Accordingly, the dynamic range decreased toward the basal end (2.1 dB). No correlation was found between the distance to the modiolus and the T-level or the M-level. Furthermore, the correlation between the insertion depth and stimulation levels was not affected by the duration of deafness, age at implantation or the time since implantation. Additionally, the T-levels showed a significant correlation with the speech perception scores (p < 0.05). Conclusions: The stimulation levels of the cochlear implants were affected by the intracochlear position of the electrode contacts, which were determined using postoperative CT scanning. Interestingly, these levels depended on the insertion depth, whereas the distance to the modiolus did not affect the stimulation levels. The T-levels increased toward the basal end of the cochlea. The level profiles were independent of the overall stimulation levels and were not affected by the biographical data of the patients, such as the duration of deafness, age at implantation or time since implantation. Further research is required to elucidate how fitting using level profiles with an increase toward the basal end of the cochlea benefits speech perception. Future investigations may elucidate an explanation for the effects of the intracochlear electrode position on the stimulation levels and might facilitate future improvements in electrode design.

Download Full-text

Speech perception in Mandarin-speaking Nucleus 24 implantees using MAPs based on Neural Response Telemetry measurements

Cochlear Implants International ◽

10.1179/cim.2004.5.supplement-1.49 ◽

2004 ◽

Vol 5 (sup1) ◽

pp. 49-51

Author(s):

Yu-Sheng Sun ◽

Tien-Chen Liu ◽

Tsung-Sheng Huang

Keyword(s):

Speech Perception ◽

Neural Response ◽

Neural Response Telemetry ◽

Telemetry Measurements ◽

Nucleus 24

Download Full-text

Neurophysiology of Cochlear Implant Users II: Comparison Among Speech Perception, Dynamic Range, and Physiological Measures

Ear and Hearing ◽

10.1097/00003446-200212000-00003 ◽

2002 ◽

Vol 23 (6) ◽

pp. 516-531 ◽

Cited By ~ 39

Author(s):

Jill B. Firszt ◽

Ron D. Chambers ◽

Nina Kraus

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Dynamic Range ◽

Physiological Measures

Download Full-text

Pediatric Outcomes with the Nucleus 24 Contour: North American Clinical Trial

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894021110s512 ◽

2002 ◽

Vol 111 (5_suppl) ◽

pp. 56-61 ◽

Cited By ~ 18

Author(s):

Steve Staller ◽

Jennifer Arcaroli ◽

Aaron Parkinson ◽

Patti Arndt

Keyword(s):

Speech Perception ◽

Hearing Aids ◽

Electrode Array ◽

Profound Hearing Loss ◽

Open Set ◽

Adults And Children ◽

The Mean ◽

Nucleus 24 ◽

Indications For Use ◽

Better Than

The Nucleus 24 Contour is a new cochlear implant that has recently undergone clinical trials in adults and children. The Contour uses the same electronics as the previous-generation Nucleus 24 (CI24M) but incorporates a downsized receiver-stimulator and a perimodiolar electrode array. The indications for use were expanded to include children as young as 12 months of age and children 24 months of age and older with severe to profound hearing loss who had open-set word recognition up to 30%. The Contour was successfully implanted in 256 children. The mean level of postoperative speech perception with the Contour was significantly better than the preoperative baseline with hearing aids on all measures. Children who had open-set speech perception in an audition-only condition before surgery demonstrated higher levels of postoperative performance with the Contour than children with no open-set speech perception before surgery.

Download Full-text

Effects of speech-coding strategies on speech perception performance in Mandarin-speaking children with Nucleus 24 cochlear implants

Cochlear Implants International ◽

10.1179/cim.2004.5.supplement-1.45 ◽

2004 ◽

Vol 5 (sup1) ◽

pp. 45-47 ◽

Cited By ~ 1

Author(s):

Chuan-Jen Hsu ◽

Shih-Hsuan Shiao ◽

Yuh-Shyang Chen ◽

Mei-Ji Horng ◽

Qian-Jie Fu

Keyword(s):

Speech Perception ◽

Cochlear Implants ◽

Speech Coding ◽

Coding Strategies ◽

Nucleus 24

Download Full-text

Population-Based Prediction of Fitting Levels for Individual Cochlear Implant Recipients

Audiology and Neurotology ◽

10.1159/000362779 ◽

2014 ◽

Vol 20 (1) ◽

pp. 1-16 ◽

Cited By ~ 8

Author(s):

Feddo B. van der Beek ◽

Jeroen J. Briaire ◽

Johan H.M. Frijns

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Predictive Models ◽

Linear Models ◽

Dynamic Range ◽

Population Based ◽

Design Data ◽

Data Set ◽

Closed Set

Objectives: This study analyzed the predictability of fitting levels for cochlear implant recipients based on a review of the clinical levels of the recipients. Design: Data containing threshold levels (T-levels) and maximum comfort levels (M-levels) for 151 adult subjects using a CII/HiRes 90K cochlear implant with a HiFocus 1/1 J electrode were used. The 10th, 25th, 50th, 75th and 90th percentiles of the T- and M-levels are reported. Speech perception of the subjects, using a HiRes speech coding strategy, was measured during routine clinical follow-up. Results: T-levels for most subjects were between 20 and 35% of their M-levels and were rarely (<1/50) below 10% of the M-levels. Furthermore, both T- and M-levels showed an increase over the first year of follow-up. Interestingly, levels expressed in linear charge units showed a clear increase in dynamic range (DR) over 1 year (29.8 CU; SD 73.0), whereas the DR expressed in decibels remained stable. T-level and DR were the only fitting parameters for which a significant correlation with speech perception (r = 0.34, p < 0.01, and r = 0.33, p < 0.01, respectively) could be demonstrated. Additionally, analysis showed that T- and M-level profiles expressed in decibels were independent of the subjects' across-site mean levels. Using mixed linear models, predictive models were obtained for the T- and M-levels of all separate electrode contacts. Conclusions: On the basis of the data set from 151 subjects, clinically applicable predictive models for T- and M-levels have been obtained. Based on one psychophysical measurement and a population-based T- or M-level profile, individual recipients' T- and M-levels can be approximated with a closed-set formula. Additionally, the analyzed fitting level data can serve as a reference for future patients. i 2014 S. Karger AG, Basel

Download Full-text