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

2016 ◽  
Vol 21 (1) ◽  
pp. 54-67 ◽  
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.

scholarly journals The evaluation of a slim perimodiolar electrode: surgical technique in relation to intracochlear position and cochlear implant outcomes

2019 ◽  
Vol 277 (2) ◽  
pp. 343-350 ◽  
Author(s):  
Floris Heutink ◽  
Berit M. Verbist ◽  
Lucas H. M. Mens ◽  
Wendy J. Huinck ◽  
Emmanuel A. M. Mylanus
Keyword(s):  
Speech Perception ◽  
Surgical Technique ◽  
Round Window ◽  
Hearing Preservation ◽  
Electrode Position ◽  
Residual Hearing ◽  
High Resolution Computed Tomography ◽  
Absolute Increase ◽  
Window Approach

Abstract Purpose In cochlear implantation (CI), the two factors that are determined by the surgeon with a potential significant impact on the position of the electrode within the cochlea and the potential outcome, are the surgical technique and electrode type. The objective of this prospective study was to evaluate the position of the slim, perimodiolar electrode (SPE), and to study the influence of the SPE position on CI outcome. Methods Twenty-three consecutively implanted, adult SPE candidates were included in this prospective cohort study conducted between December 2016 and April 2019. Mean age at surgery was 59.5 years. Mean preoperative residual hearing was 92.2 dB. Intra-operative fluoroscopy and high-resolution computed tomography scans were performed to evaluate electrode position after insertion using a cochleostomy (CS) approach. Follow-up was 12 months after implantation; residual hearing (6–8 weeks) and speech perception (6–8 weeks and 12 months) were evaluated in relation to the intracochlear SPE position. Results In most patients in whom the SPE was positioned in the scala tympani residual hearing was preserved [mean absolute increase in PTA of 4.4 dB and 77.2% relative hearing preservation (RHP%)]. Translocation into the scala vestibuli occurred in 36% of the insertions, resulting in a mean absolute increase in PTA of 17.9 dB, and a RHP% of 19.2%. Participants with a translocation had poorer speech perception scores at 12-month follow-up. Conclusion Given the incidence of CS-associated translocations with the SPE and the negative effect on outcome, it is advised to insert the SPE using the (extended) round window approach.

Speech perception performance for 100 post-lingually deaf adults fitted with Neurelec cochlear implants: Comparison between Digisonic®Convex and Digisonic®SP devices after a 1-year follow-up

2010 ◽  
Vol 130 (11) ◽  
pp. 1267-1273 ◽  
Author(s):  
Diane S. Lazard ◽  
Philippe Bordure ◽  
Geneviève Lina-Granade ◽  
Jacques Magnan ◽  
Renaud Meller ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implants ◽  
Deaf Adults

Use of Visual Feedback to Treat Negative Intraoral Air Pressures of Preschoolers With Cochlear Implants

2000 ◽  
Vol 9 (1) ◽  
pp. 21-35 ◽  
Author(s):  
Maureen B. Higgins ◽  
Elizabeth A. McCleary ◽  
Laura Schulte
Keyword(s):  
Speech Perception ◽  
Speech Production ◽  
Cochlear Implants ◽  
Fundamental Frequency ◽  
Visual Feedback ◽  
The Other ◽  
Deaf Children ◽  
Frequent Use ◽  
Before And After

The primary purpose of this study was to determine if negative intraoral air pressures (−P o ) produced by young deaf children can be treated effectively with visual feedback. We used two forms of visual feedback. One was a display of the P o signal on an oscilloscope, and the other was movement of cellophane streamers placed in front of the children’s mouths. Participants were two 5-year-old boys who had been using cochlear implants (CIs) for less than 6 months. Both children were congenitally deafened and had very limited speech production and perception skills. In addition to frequent usage of −P o , both children exhibited deviant phonatory behaviors, so phonatory goals were incorporated into treatment. The magnitude and direction of P o was monitored, as well as fundamental frequency and electroglottograph cycle width. Data were collected at baseline, before and after treatment sessions, and 7 weeks after termination of treatment. One child responded well to treatment of −P o with both forms of visual feedback, and progress was maintained at follow-up. For the other child, +P o occurred more frequently as the study progressed, and he rarely produced −P o by the end of the investigation. However, because changes were evident in baseline as well as during treatment, it is difficult to attribute his more frequent use of +P o specifically to treatment. The phonation of the two children changed in ways that were consistent with their phonatory goals, although the degree of change was not always significant. Change was more evident for phonatory behaviors that could be shaped with visual feedback. Although both children exhibited some undesirable speech/voice behaviors in response to visual feedback, there was no evidence of long-lasting mislearning. Although our data are limited, it appears that treatment of −P o can be efficacious for some young children with CIs, even those with very poor speech perception and speech production skills. Further, treatment of −P o can be incorporated effectively with other speech production goals.

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

2014 ◽  
Vol 20 (1) ◽  
pp. 1-16 ◽  
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

Signal Coding in Cochlear Implants: Exploiting Stochastic Effects of Electrical Stimulation

2003 ◽  
Vol 112 (9_suppl) ◽  
pp. 14-19 ◽  
Author(s):  
Jay T. Rubinstein ◽  
Robert Hong
Keyword(s):  
Electrical Stimulation ◽  
Speech Perception ◽  
Cochlear Implants ◽  
Speech Processing ◽  
Music Perception ◽  
Dynamic Range ◽  
High Rate ◽  
Monosyllabic Word ◽  
Stochastic Effects ◽  
Processing Strategies

Speech perception in quiet with cochlear implants has increased substantially over the past 17 years. If current trends continue, average monosyllabic word scores will be nearly 80% by 2010. These improvements are due to enhancements in speech processing strategies, to the implantation of patients with more residual hearing and shorter durations of deafness, and to unknown causes. Despite these improvements, speech perception in noise and music perception are still poor in most implant patients. These deficits may be partly due to poor representation of temporal fine structure by current speech processing strategies. It may be possible to improve both this representation and the dynamic range of electrical stimulation through the exploitation of stochastic effects produced by high-rate (eg, 5-kilopulse-per-second) pulse trains. Both the loudness growth and the dynamic range of low-frequency sinusoids have been enhanced via this technique. A laboratory speech processor using this strategy is under development. Although the clinical programming for such an algorithm is likely to be complex, some guidelines for the psychophysical and electrophysiological techniques necessary can be described now.

Effect of Increased IIDR in the Nucleus Freedom Cochlear Implant System

2007 ◽  
Vol 18 (09) ◽  
pp. 777-793 ◽  
Author(s):  
Laura K. Holden ◽  
Margaret W. Skinner ◽  
Marios S. Fourakis ◽  
Timothy A. Holden
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Sound Field ◽  
The Other ◽  
Threshold Levels ◽  
Speech In Noise ◽  
El Sistema ◽  
Initial Activation ◽  
Implant System

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.

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