Bilateral cochlear implants: a way to optimize auditory perception abilities in deaf children?

doi:10.1016/j.ijporl.2004.04.029

International Journal of Pediatric Otorhinolaryngology

Volume 68, Issue 10, October 2004, Pages 1257-1266

https://doi.org/10.1016/j.ijporl.2004.04.029 Get rights and content

Summary

Objectives:

The Würzburg bilateral cochlear implant (CI) program was started with the aim to improve the patients’ communicative abilities in complex listening situations. In this study, the auditory skills of children using bilateral cochlear implants were evaluated.

Study design and settings:

Qualitative data based on free observations in the rehabilitation setup were collected in 39 bilaterally implanted children. A speech discrimination in noise test was performed in 18 of these children; lists of bisyllabic words were presented in noise at a signal to noise ratio (SNR) of +15 dB.

Results:

Qualitative and quantitative data show clearly that bilateral CI improves the children’s communicative behaviour, especially in complex listening situations. Children examined with the speech in noise test scored significantly better under the bilateral condition compared to the unilateral condition. Integration of the second implanted side and use of binaural information was observed to be easier and faster in children with a short time lag between both implants.

Conclusions:

To be able to obtain optimal benefit from bilateral cochlear implants, an intensive rehabilitation program is necessary. The important aspects of such a program are creating realistic expectations in older children before implantation; performing the first processor fitting of the second side with the first side switched on; and separate intensive training with the new system in order to balance out the hearing competence of the second CI with that of the first.

Introduction

Cochlear implantation is an established successful method for the rehabilitation of hearing impaired adults and children. Prelingually deafened children using cochlear implant (CI) have also reached an outstanding level of auditory capabilities [1], [2]. The routine practice, so far, has been to implant one side only. The selection of the ear to implant depends on several factors such as hearing thresholds, speech discrimination abilities, excitability of the eighth nerve and imaging findings. Being restricted to a monaural hearing situation implies that implanted children and adults, even those reaching high levels of auditory performance are still deprived of the advantages of binaural and spatial hearing.

The ability of a listener to communicate and navigate successfully in everyday environments depends, to a large part, on his/her sensitivity to binaural information available in these situations. The two primary binaural cues that make it possible to localize sound sources, and detect and/or understand speech in noise in typical listening situations are intensity differences in the signals reaching the two ears (interaural intensity differences) and differences in time of arrival of signals reaching the two ears (interaural time differences). Patients who are not able to process these binaural cues are almost certain to have difficulties localizing sound sources, detecting and understanding speech in noisy situations.

Bilateral CI has been previously reported only sporadically in the literature [3], [4], [5]. Recent experience with bilaterally implanted adult patients have shown a significant improvement in auditory capabilities, especially those related to sound localization and speech discrimination in background noise [6], [7], [8], [9]. Following the improvement observed in adults, children were also included in the bilateral implantation program since 1998.

Several difficulties are related to data collection in young children due to the complexity of the standardized procedures testing binaural hearing and their shorter attention span. Observations in rehabilitation, on the other hand, offer a feasible method for gathering information related to the binaural performance of these children (qualitative data). Furthermore, quantitative data were collected using speech discrimination in noise tests performed on older children and on children who had sufficient speech development to be able to perform the test. The results of observation in rehabilitation, together with the preliminary results of the speech in noise test are presented in this paper. To our knowledge, this is the first report describing auditory skills in a group of children using bilateral cochlear implants.

Section snippets

Population

Data from 39 children with bilateral implantation are included in this report. The children’s group is heterogeneous with regard to age at first and second implantation, time lag between implants and onset of hearing loss (Table 1). The age at the first implantation ranged from 8 months to 16 years and 4 months. Age at the second implantation varied between 1 year and 7 months to 16 years and 4 months. Ten children were implanted on the second side within 1 year following the first

Speech discrimination in noise test results (quantitative data)

Standard speech audiometry in quiet with the “Mainzer” or the “Göttinger” speech lists is a part of the routine postoperative audiological evaluation procedure for all CI children. In bilaterally implanted children included in this study, the mean word discrimination scores tested with both CIs (86.4%) showed a tendency to be higher than that reached with the left CI (75.1%) or the right CI alone (71.8%). The difference between the bilateral condition and the best unilateral condition was

Summary and discussion

The results of speech audiometry showed that children reached a higher WDS% (word discrimination scores) in quiet with both CI compared to one CI. There was a significant improvement in speech discrimination abilities in noise with the bilateral condition compared to the unilateral condition. The mean difference of speech discrimination in noise with the unilateral compared to the bilateral condition was 18.4 ± 8.2%. The difference between the two conditions, tested by the t-test, was

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Cited by (113)

Bilateral cochlear implantation versus unilateral cochlear implantation in deaf children: Effects of sentence context and listening conditions on recognition of spoken words in sentences
2020, International Journal of Pediatric Otorhinolaryngology
Citation Excerpt :
The current study focused on word recognition within sentences in children with bilateral CIs. A number of studies have investigated the effect of bilateral CIs on word recognition in noisy conditions [4,10,11]. These studies have been limited to isolated word recognition, aiming to separate the semantic level from auditory-linguistic processing.
Previous studies have investigated the efficacy of bilateral cochlear implants (CIs) in deaf children. The current study focused on the use of sentence-context information in different listening conditions to better explain the benefits of bilateral cochlear implantation. We compared the word recognition abilities of children with bilateral CIs and children with unilateral CIs in relation to sentence context and listening conditions. Additionally, we investigated whether sentence context- and listening condition-dependent word recognition scores can differentiate children with bilateral CIs from children with unilateral CIs.
Twenty children with bilateral CIs and 20 children with unilateral CIs participated in this study. All children were presented with semantically controlled sentences (high vs. low predictability) in quiet and noisy conditions and were asked to repeat the final words of each sentence.
Children with bilateral CIs had significantly higher word recognition scores than children with unilateral CIs on words embedded in both high- and low-predictability sentences in noisy conditions. The two groups recognized more words in high-predictability sentences than in low-predictability sentences in noisy conditions. The scores on the high-predictability sentences in noisy conditions significantly differentiated children with bilateral CIs from children with unilateral CIs.
Bilateral cochlear implantation is more advantageous than unilateral cochlear implantation at the auditory-linguistic processing level in complex listening conditions.
Early auditory skills development in Mandarin speaking children after bilateral cochlear implantation
2018, International Journal of Pediatric Otorhinolaryngology
The purpose of the present study was: (1) to investigate the early auditory preverbal behaviors of infants/toddlers with bilateral cochlear implants (BCI), and to compare their performance with that of unilateral cochlear implant (UCI) peers; (2) to investigate effects of age of implantation, education level of caregivers, living environment, and unaided behavioral threshold before operation on early auditory preverbal development.
The evaluation material of the present study was the Mandarin version of the LittlEARS^® Auditory Questionnaire (LEAQ). Assessments were administrated at 0, 1, 2, 3, 6, 9, 12 and 24 months after cochlear implants (CIs) were switched on. A one-way ANOVA was used to analyze the differences of early auditory preverbal performance between each two contiguous test intervals. A two-sample t-test was used to analyze the difference of behaviors between infants/toddlers with BCI and UCI. Non-parametric tests were used to analyze the effects of potential affecting factors on auditory preverbal skills.
Nineteen subjects aging from 9 to 54 months (Mean = 22.7, SD = 13.7) were recruited in the study. At each evaluation time, the average scores of LEAQ were 4.58, 9.00, 16.00, 18.56, 22.00, 31.50, 29.67, and 34.35 respectively. The total score and semantic auditory behavior score increased significantly during the second months after CIs activation (the total score: LSD-t = 3.157, p = 0.030; semantic auditory behavior score: LSD-t = 1.972, p = 0.034). The score of BCI group was significantly higher than UCI group after 1, 3 and 6 months of CI use (1 month: t = 3.257, p = 0.002; 3 months: t = 5.042, p = 0.000; 6 months: t = 4.054, p = 0.000). Education level of caregivers had a positive effect on receptive auditory behavior (H = 6.538, p = 0.035) after CIs switched on for 3 months. The LEAQ performance was not significantly correlated with pre-operative behavioral threshold although they showed a trend of negative correlation in the first 3 months after activation.
The study indicated that infants and toddlers who underwent BCI had better auditory preverbal skills than their UCI peers. Higher caregivers' education level positively correlated with the early development of auditory preverbal skills. Better pre-operative behavioral threshold might also benefit early auditory preverbal skills development for BCI children.
Does a lack of auditory experience affect sequential learning?
2018, Cognition
To understand the interaction between sensory experiences and cognition, it is critical to investigate the possibility that deprivation in one sensory modality might affect cognition in other modalities. Here we are concerned with the hypothesis that early experience with sound is vital to the development of domain-general sequential processing skills. In line with this hypothesis, a seminal empirical study found that prelingually deaf children had impaired sequence learning in the visual modality. In order to assess the limits of this hypothesis, the current study employed a different visual sequence learning task in an investigation of prelingually deaf children with cochlear implants and normal hearing children. Results showed statistically significant learning in each of the two groups, and no significant difference in the amount of learning between groups. Moreover, there was no association between the age at which the child received their implant (and thus access to electric hearing) and their performance on the sequential learning task. We discuss key differences between our study and the previous study, and argue that the field must reconsider claims about domain-general cognitive impairment resulting from early auditory deprivation.
Sequential pediatric bilateral cochlear implantation: The effect of time interval between implants
2017, International Journal of Pediatric Otorhinolaryngology
To examine speech intelligibility in children subjected to sequential bilateral cochlear implants (CI) surgery and to assess the influence of the inter-stage interval duration.
Binaural hearing recovery can have additional benefits, especially in speech and language development in patients with congenital profound sensorineural hearing loss; so recently there has been an increase in the number of children receiving bilateral CI.
Twenty-seven children who underwent sequential bilateral cochlear implant (SBCI) with a short (1–3 yrs), medium (4–6 yrs) and long (7–12 yrs) range interval between both implantations, respectively, were evaluated. All patients underwent periodic speech perception test in quiet and noise after second implant activation in three conditions: with the first or second implant alone and with both implants. Results were examined according to the inter-stage interval.
Speech intelligibility in noise was significantly better under bilateral conditions than either ear alone, in all three groups. Small improvements were seen in quiet, especially in the third group (6–12 yrs).
Benefits of second implant in the early-implanted children and after a short inter-implant delay are more evident. However our study support that, even after a long period of deafness and despite a prolonged inter-stage interval, sequential bilateral cochlear implantation should be considered.
Level of Evidence: Level 4.
The experience of bilateral cochlear implantation in a child with LEOPARD syndrome
2016, International Journal of Pediatric Otorhinolaryngology
We present a 3-year old boy with Leopard syndrome. His clinical manifestations included a congenital bilateral sensorineural hearing loss. He underwent cochlear implantation on the right side at age 1 year and on the left side at age 1.5 years. The patient is doing very well and mainstreamed in a regular pre-school program with a teacher of the deaf and home based speech therapy. Bilateral cochlear implantation in the case of a child with Leopard syndrome can be successful.
Comparative study between unilateral and bilateral cochlear implantation in children of 1 and 2 years of age
2016, Acta Otorrinolaringologica Espanola
Los estudios que han evaluado la efectividad de los implantes cocleares bilaterales en niños sugieren una mejoría de la capacidad auditiva en cuanto a la localización del sonido y la discriminación del lenguaje. En este trabajo mostramos las diferencias en los logros audio-lingüísticos con la implantación coclear bilateral precoz frente a la unilateral, así como las diferencias entre la implantación bilateral secuencial y simultánea.
Presentamos 88 niños diagnosticados de hipoacusia neurosensorial profunda bilateral tratados mediante implantación coclear bilateral en 32 casos, y unilateral en 56 casos, durante los primeros 12 meses (27 niños) y entre los 12 y 24 meses (61 niños). Se compararon los resultados en la audiometría tonal, en las escalas IT-Mais, Nottingham y LittlEars, así como en las pruebas logoaudiométricas.
No se detectan diferencias significativas en los umbrales auditivos y en los cuestionarios IT-Mais, Nottingham y LittlEars entre los niños implantados bilateral y unilateralmente, tanto en el primer como en el segundo año. Las pruebas verbales sí que muestran diferencias estadísticamente significativas, ya que los niños con un implante coclear bilateral alcanzan antes el 100% en el reconocimiento de bisílabos y frases, sin que los niños con un solo implante lleguen a igualar dichos resultados a los 5 años de la cirugía. No existen diferencias entre implantación bilateral simultánea y secuencial.
Con este estudio remarcamos la importancia de asegurar un buen cribado audiológico precoz, para poder llevar a cabo una implantación coclear temprana, a ser posible bilateral, logrando así un desarrollo de las habilidades audio-lingüísticas equiparable al de los normooyentes.
The studies that have evaluated the effectiveness of bilateral cochlear implantation in children suggest an improvement in hearing about sound localization and speech discrimination. In this paper we show the differences in audio-linguistic achievements with early bilateral cochlear implantation versus unilateral, and differences between simultaneous and sequential bilateral implantation.
We present 88 children with bilateral profound sensorineural hearing loss, treated with bilateral cochlear implantation in 32 cases and unilateral in 56 cases, during the first 12 months (27 children) of life and between 12 and 24 months (61 children). We conducted a statistical comparison of both groups in the audiometry, IT-Mais, Nottingham, LittlEars scales and verbal tests.
No significant differences in hearing thresholds and questionnaires between unilateral and bilateral implantation were detected in either the first or second year. Verbal tests do show statistically significant differences: children with bilateral cochlear implant obtain 100% recognition of disyllabic and phrases within 2-3 years after implantation whilst children with one implant do not obtain those results at 5 years after surgery. No differences between simultaneous and sequential bilateral implantation were detected.
We emphasize the importance of ensuring good early audiological screening, to carry out an early and bilateral cochlear implantation with the consequent development of audio-language skills similar to normal hearing children.

View all citing articles on Scopus

¹: Present address: MED-EL, Innsbruck, Austria.

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Bilateral cochlear implants: a way to optimize auditory perception abilities in deaf children?

Summary

Objectives:

Study design and settings:

Results:

Conclusions:

Introduction

Section snippets

Population

Speech discrimination in noise test results (quantitative data)

Summary and discussion

Int. J. Pediatr. Otorhinol.

Audiological findings in children using cochlear implants (CI)

Laryngorhinootologie

Results of cochlear implantation in patients with severe to profound hearing: implications for patient selection

Audiology

Bilateral electrical stimulation of a congenitally-deaf ear and of an acquired-deaf ear

Acta Otolaryngol. (Stockh.)

Binaural cochlear implants

Am. J. Otol.

Fusion and lateralisation study with two binaural cochlear implant subjects

Ann. Otol. Rhinol. Laryngol.

Binaural cochlear implantation: a case report discussing preliminary results

Eur. Arch. Otorhinolaryngol.

Results of bilateral cochlear implantation

Eur. Arch. Otorhinolaryngol.