Shorter Duration Of Deafness Research Articles

Correlation between the etiology of severe hearing loss and endolymphatic hydrops.

This study aimed to investigate correlation between the presence of endolymphatic hydrops(EH) and factors such as causes of hearing loss, patient age, duration of deafness, and results of vestibular function tests. We retrospectively reviewed medical charts of 128 ears of cochlear implantees who were not considered relevant to Meniere's disease. When comparing group with genetic variants of GJB2, SLC26A4, LMX1A and other genetic mutation group, the proportion of vestibular EH and cochlear EH found in group with genetic variants of GJB2, SLC26A4, LMX1A was significantly higher than group with other genetic etiology (p < 0.01) or the group with all the other causes of hearing loss (p < 0.01). The rate of vestibular and cochlear EH detection was higher in younger patients (41.5% and 35.4%) than in older patients (25.4% and 20.6%). A higher ratio of vestibular and cochlear EH was observed in patients with a longer duration of deafness (37.5% and 31.3%) than those with a shorter duration of deafness (29.7% and 25.0%). The group with vestibular EH showed a higher incidence of abnormal findings in the caloric test (42.9%) than the group without vestibular EH (28.2%). Patients with genetic variants of GJB2, SLC26A4, LMX1A, younger patients, those with longer deaf durations showed a higher prevalence of vestibular and cochlear EH, implying EH appears to be formed as a developmental disorder in association with a certain set of genetic variants, rather than a phenotypic marker as a result of severe to profound hearing loss.

Speech Perception and Quality-of-Life Outcomes in Mandarin-Speaking Postlingual Deaf Adults With Cochlear Implant: Any Difference With the Intonation Language Users?

To evaluate the effects of related factors on long-term speech perception and quality-of-life (QoL) outcomes in postlingual deaf Mandarin-speaking adult cochlear implant (CI) recipients and to assess any differences between tone language and other intonation language CI adult users. Retrospective cases review. Tertiary referral center. Forty-five adult CI recipients (48 implanted ears). Post-CI outcomes were evaluated after follow-ups of more than 24 months using speech perception tests and QoL questionnaires. We analyzed the related factors affecting CI outcomes. A shorter duration of profound deafness was predictive factors for better post-CI speech perception. Earlier implantation and better performance of vowel scores were predictive of better subjective improvements in social and emotional life. Post-CI vowel scores of over 56% indicated promising improvements in QoL. Shorter duration of deafness could have better post-CI speech perception. Post-CI vowel scores instead of monosyllable words have the more potential to predict the QoL in Mandarin-speaking adult CI recipients.

Factors that influence outcomes and device use for pediatric cochlear implant recipients with unilateral hearing loss.

Candidacy criteria for cochlear implantation in the United States has expanded to include children with single-sided deafness (SSD) who are at least 5 years of age. Pediatric cochlear implant (CI) users with SSD experience improved speech recognition with increased daily device use. There are few studies that report the hearing hour percentage (HHP) or the incidence of non-use for pediatric CI recipients with SSD. The aim of this study was to investigate factors that impact outcomes in children with SSD who use CIs. A secondary aim was to identify factors that impact daily device use in this population. A clinical database query revealed 97 pediatric CI recipients with SSD who underwent implantation between 2014 and 2022 and had records of datalogs. The clinical test battery included speech recognition assessment for CNC words with the CI-alone and BKB-SIN with the CI plus the normal-hearing ear (combined condition). The target and masker for the BKB-SIN were presented in collocated and spatially separated conditions to evaluate spatial release from masking (SRM). Linear mixed-effects models evaluated the influence of time since activation, duration of deafness, HHP, and age at activation on performance (CNC and SRM). A separate linear mixed-effects model evaluated the main effects of age at testing, time since activation, duration of deafness, and onset of deafness (stable, progressive, or sudden) on HHP. Longer time since activation, shorter duration of deafness, and higher HHP were significantly correlated with better CNC word scores. Younger age at device activation was not found to be a significant predictor of CNC outcomes. There was a significant relationship between HHP and SRM, with children who had higher HHP experiencing greater SRM. There was a significant negative correlation between time since activation and age at test with HHP. Children with sudden hearing loss had a higher HHP than children with progressive and congenital hearing losses. The present data presented here do not support a cut-off age or duration of deafness for pediatric cochlear implantation in cases of SSD. Instead, they expand on our understanding of the benefits of CI use in this population by reviewing the factors that influence outcomes in this growing patient population. Higher HHP, or greater percentage of time spent each day using bilateral input, was associated with better outcomes in the CI-alone and in the combined condition. Younger children and those within the first months of use had higher HHP. Clinicians should discuss these factors and how they may influence CI outcomes with potential candidates with SSD and their families. Ongoing work is investigating the long-term outcomes in this patient population, including whether increasing HHP after a period of limited CI use results in improved outcomes.

Outcomes of Cochlear Implantation in Patients with Post-Meningitis Deafness: A Systematic Review and Narrative Synthesis.

Summarise outcomes following cochlear implantation (CI) in patients with post-meningitis deafness. Systematic review and narrative synthesis. Databases searched: Medline, Pubmed, Embase, Web of Science, Cochrane Collection and ClinicalTrials.gov. No limits placed on language or year of publication. Studies with a minimum of 20 individuals with post-meningitis deafness were included. Review conducted in accordance with the PRISMA statement. Searches identified 906 abstracts and 291 full texts. Of these, 19 studies met the inclusion criteria, reporting outcomes in 610 patients with 650 implants. Audiological outcomes improved across all studies following cochlear implantation. 7 studies demonstrated a statistically significant difference between pre and post-CI outcomes. Patients with no cochlear ossification, full electrode insertion, shorter duration of deafness and no neurological sequelae generally appeared to perform best. A total of 31 minor and 19 major complications were reported, with 15 cases of reimplantation. The methodological quality of the included studies was sufficient, predominantly consisting of cohort studies. 15 studies were OCEBM grade III and 4 studies were OCEBM grade IV. All studies had a minimum of 20 individuals with post-meningitic deafness and used multi-channel cochlear implant devices. Audiological outcomes following cochlear implantation in meningitis are satisfactory, providing functional levels of speech perception and intelligibility. Improvement in hearing is dependent on the amount of cochlear ossification, duration of deafness prior to implantation, electrode insertion depth and presence of neurological sequalae. Cochlear implantation in meningitis patients can be challenging due to the presence of ossification and inaccuracies of pre-operative imaging. Therefore, early and bilateral implantation is recommended in all patients with post-meningitis hearing loss to improve the likelihood of full electrode insertion.

Health-related quality of life in South African children who use cochlear implants

Objective: To describe health-related quality of life (HRQoL) outcomes of school-going paediatric cochlear implant (CI) recipients in a South African cohort from the perspectives of parents.Design: Parents of school-going CI recipients completed the Children with Cochlear Implants: Parental Perspectives (CCIPP) CI-specific HRQoL questionnaire. The effect of different demographic variables on HRQoL outcomes was also determined.Study sample: The study sample included 54 parents of school-going (mean age = 12.2 years; SD = 3.6; range = 6.6–18.3 years) CI recipients with at least six months CI experience.Results: Children’s communication and general functioning with a CI received the most positive parental ratings. Among a number of confirmed statistically significant (p < 0.05) associations between HRQoL outcomes and demographic variables, pre-lingual onset of deafness was linked to better HRQoL in terms of general functioning and well-being. While shorter duration of deafness and unilateral implantation were associated with higher parental ratings for self-reliance and well-being respectively, longer duration of CI use was linked to improved HRQoL outcomes in terms of general functioning.Conclusion: Parents assigned positive ratings to their child’s HRQoL. This exploration of children’s HRQoL related to their CIs contributes to evidence-based paediatric CI services that promote optimal psychosocial outcomes.

Effect of Tinnitus and Duration of Deafness on Sound Localization and Speech Recognition in Noise in Patients With Single-Sided Deafness

Patients with single-sided deafness (SSD) often experience poor sound localization, reduced speech understanding in noise, reduced quality of life, and tinnitus. The present study aims to evaluate effects of tinnitus and duration of deafness on sound localization and speech recognition in noise by SSD subjects. Sound localization and speech recognition in noise were measured in 26 SSD and 10 normal-hearing (NH) subjects. Speech was always presented directly in front of the listener. Noise was presented to the deaf ear, in front of the listener, or to the better hearing ear. Tinnitus severity was measured using visual analog scale and Tinnitus Handicap Inventory. Relative to NH subjects, SSD subjects had significant deficits in sound localization and speech recognition in all listening conditions (p < .001). For SSD subjects, speech recognition in noise was correlated with mean hearing thresholds in the better hearing ear (p < .001) but not in the deaf ear. SSD subjects with tinnitus performed poorer in sound localization and speech recognition in noise than those without tinnitus. Shorter duration of deafness was associated with greater tinnitus and sound localization difficulty. Tinnitus visual analog scale and Tinnitus Handicap Inventory were highly correlated; the degree of tinnitus was negatively correlated with sound localization and speech recognition in noise. Those experiencing noticeable tinnitus may benefit more from cochlear implantation than those without; subjective tinnitus reduction may be correlated with improved sound localization and speech recognition in noise. Subjects with longer duration of deafness demonstrated better sound localization, suggesting long-term compensation for loss of binaural cues.

Speech Production Quality of Cochlear Implant Users with Respect to Duration and Onset of Hearing Loss

Purpose: To assess whether postlingual onset and shorter duration of deafness before cochlear implant (CI) provision predict higher speech intelligibility results of CI users. Methods: For an objective judgement of speech intelligibility, we used an automatic speech recognition system computing the word recognition rate (WR) of 50 adult CI users and 50 age-matched control individuals. All subjects were recorded reading a standardized text. Subjects were divided into three groups: pre- or perilingual deafness (A), both >2 years before implantation, postlingual deafness <2 years before implantation (B), or postlingual deafness >2 years before implantation (C). Results: CI users with short duration of postlingual deafness (B) had a significantly higher WR (median 74%) than CI users with long duration of postlingual deafness (C; 68%, p < 0.001) or pre-/perilingual onset (A; 56%, p < 0.001). Compared to their control groups only CI users with short duration of postlingual deafness reached similar WR, others showed significantly lower WR. Other factors such as hearing loss onset, duration of CI use, or duration of amplified hearing showed no consistent influence on speech quality. Conclusions: The speech production quality of adult CI users shows dependencies on the onset and duration of deafness. These features need to be considered while planning rehabilitation.

Results of Speech Audiometry Testing in Case of Transcranial CROS Depend on Duration of Deafness

In single sided deafness, treatment with transcranial CROS makes pseudo stereophonic listening possible. This leads to improved speech understanding in noise. However, several reports show large variations between the individual results of the benefit by speech audiometry in noise. One possible factor is the duration and changes in the auditory pathway between the onset of deafness to CROS supply. 18 patients with single sided deafness have tested a transcranial CROS supply. The speech intelligibility thresholds were evaluated in 2 spatial hearing situations each with CROS and unaided. When speech was arriving at 45° from the deaf ear and noise at 45° from the hearing ear, a significant improvement of speech reception threshold for 50% intelligibility was detected by CROS supply compared the medians. Patients with longer duration of deafness showed higher benefit by an average of -4.0 dB, in contrast to patients with short duration of deafness. In the reversed situation, that speech on the hearing ear and noise on the deaf ear was a significant deterioration observed, an average of 3.1 dB at longer deafened patients. In addition, a highly significant correlation was found with the individual changes in the speech recognition threshold between the two situations. The duration of deafness is an essential factor in the individual benefit estimate for treatment with transcranial CROS supply. The time frame for audimetrically proven changes in the auditory pathway as a result of unilateral auditory deprivation can be estimated to about 1-3 years. Patients with short duration of deafness have low or no benefit from transcranial CROS supply.

Predicting speech perception outcomes following cochlear implantation in adults with unilateral deafness or highly asymmetric hearing loss

Objective: Unilateral deafness and highly asymmetric hearing loss can impair listening abilities in everyday situations, create substantial audiological handicap, and reduce overall quality of life. Preliminary evidence suggests that cochlear implantation may be effective in reversing some of these detrimental effects. Patient-level data from existing studies were re-analysed to explore potential factors that may be predictive of improved speech perception scores following implantation.Methods: Logistic regression modelling examined whether improved speech perception following implantation under various listening conditions was related to the duration of deafness of the severe-to-profoundly deaf ear and/or the level of hearing in the better ear.Results: Patients with a shorter duration of deafness were more likely to improve in listening conditions that created a less favourable SNR at the implanted ear than the non-implanted ear. Those with more residual hearing in the better ear were more likely to improve in the listening condition that created a less favourable SNR at that ear.Discussion: The analysis suggests that characteristics of both ears may be relevant when seeking to identify those candidates who are likely to obtain benefit to speech perception following cochlear implantation.

Does cochlear implantation restore music appreciation?

Does cochlear implantation restore music appreciation?

A cochlear implant user with exceptional musical hearing ability

Although the perception of music is generally poor in cochlear implant users, there are a few excellent performers. Objective: The aim of this study was the assessment of different aspects of music perception in one exceptional cochlear implant user. Design: The assessments included pitch direction discrimination, melody and timbre recognition, relative and absolute pitch judgment, and consonance rating of musical notes presented through the sound processor(s). Study sample: An adult cochlear implant user with musical background who lost her hearing postlingually, and five normally-hearing listeners with musical training participated in the study. Results: The CI user discriminated pitch direction for sounds differing by one semitone and recognized melody with nearly 100% accuracy. Her results in timbre recognition were better than average published data for cochlear implant users. Her consonance rating, and relative and absolute pitch perception were comparable to normally-hearing listeners with musical training. Conclusion: The results in this study showed that excellent performance is possible on musical perception tasks including pitch perception using present day cochlear implant technologies. Factors that may explain this user's exceptional performance are short duration of deafness, pre- and post-deafness musical training, and perfect pitch abilities before the onset of deafness.

Language and verbal reasoning skills in adolescents with 10 or more years of cochlear implant experience.

The purpose of this study is to identify factors predictive of successful English language outcomes in adolescents who received a cochlear implant (CI) between 2 and 5 yrs of age. All 112 participants had been part of a previous study examining English language outcomes at the age of 8 and 9 yrs with CIs. The participants were given a battery of language and verbal reasoning tests in their preferred communication mode along with measures of working memory (digit span) and verbal rehearsal speed (sentence repetition duration). The degree to which students' language performance was enhanced when sign was added to spoken language was estimated at both test sessions. Multiple linear regression analyses were used to document factors contributing to overall language outcomes. A substantial proportion of the adolescents obtained test scores within or above 1SD compared with hearing age-mates in the tests' normative samples: 71% on a verbal intelligence test, 68% on a measure of language content, 71% on receptive vocabulary, and 74% on expressive vocabulary. Improvement in verbal intelligence scores over an 8-yr interval exceeded expectation based on age-mates in the test's normative sample. Better English language outcomes were associated with shorter duration of deafness before cochlear implantation, higher nonverbal intelligence, higher family socioeconomic status, longer digit spans, and faster verbal rehearsal speed as measured by sentence repetition rate. Students whose current receptive vocabulary scores were not enhanced by the addition of signs also exhibited higher English language scores than those without sign enhancement; however, sign enhancement demonstrated in the elementary school years was not predictive of later high-school language skills. Results of this study support the provision of CIs to children at the youngest age possible. In addition, it highlights the substantial role that cognition plays in later language outcomes. Although the students' use of sign to enhance language skills during the elementary years does not appear to have a negative impact on later language skills, students who continue to rely on sign to improve their vocabulary comprehension into high school typically exhibit poorer English language outcomes than students whose spoken language comprehension parallels or exceeds their comprehension of speech + sign. Overall, the language results obtained from these teenagers with more than 10 yrs of CI experience reflect substantial improvement over the verbal skills exhibited by adolescents with similar levels of hearing loss before the advent of CIs. These optimistic results were observed in teenagers who were among the first in the United States and Canada to receive a CI. We anticipate that the use of improved technology that is being initiated at even younger ages should lead to age-appropriate language levels in an even larger proportion of children with CIs.

COMBINED THERAPY (INTRATYMPANIC DEXAMETHASONE + HIGH-DOSE PREDNISONE TAPER) FOR IDIOPATHIC SUDDEN SENSORINEURAL HEARING LOSS

COMBINED THERAPY (INTRATYMPANIC DEXAMETHASONE + HIGH-DOSE PREDNISONE TAPER) FOR IDIOPATHIC SUDDEN SENSORINEURAL HEARING LOSS

Clinical Relevance of Quality of Life Outcome in Cochlear Implantation in Postlingually Deafened Adults

To evaluate the benefits of cochlear implantation in postlingually deafened adults and estimate the clinical relevance of these benefits. Prospective intervention study. Tertiary referral hospital. Forty-four postlingually deafened adults. Cochlear implantation with a Clarion CII HiFocus 1 or HiRes 90K. The Health Utility Index Mark II (HUI2) and Nijmegen Cochlear Implant Questionnaire were administered to quantify health-related QoL (HRQoL); utilities were obtained from the HUI2 and time trade-off instrument. Speech perception scores were analyzed. Patient factors were correlated with postimplant HRQoL and speech perception scores. Clinical significant benefit was estimated using the minimal clinically significant difference (MID) and effect size (ES). The results show a significant improvement in HRQoL and speech perception (p < 0.001). The improvement in HRQoL is mainly obtained in the first months after implantation and is largest in the categories concerning physical functioning (hearing). A shorter duration of deafness (p = 0.003) and higher educational level (p = 0.015) were significant predictors of better speech perception. Cochlear implantation proved to be a cost-effective procedure. By using the MID and ES, we found important clinical improvements on 6 health domains of the Nijmegen Cochlear Implant Questionnaire and on the sensation domain of the HUI2 in most patients; all but 1 of the ESs were large. Cochlear implants have a large and significant positive impact on HRQoL and speech perception and are cost-effective. These improvements are clinically relevant as measured by the MID.

Multicenter U.S. Bilateral MED-EL Cochlear Implantation Study: Speech Perception over the First Year of Use

Binaural hearing has been shown to support better speech perception in normal-hearing listeners than can be achieved with monaural stimulus presentation, particularly under noisy listening conditions. The purpose of this study was to evaluate whether bilateral electrical stimulation could confer similar benefits for cochlear implant listeners. A total of 26 postlingually deafened adult patients with short duration of deafness were implanted at five centers and followed up for 1 yr. Subjects received MED-EL COMBI 40+ devices bilaterally; in all but one case, implantation was performed in a single-stage surgery. Speech perception testing included CNC words in quiet and CUNY sentences in noise. Target speech was presented at the midline (0 degrees), and masking noise, when present, was presented at one of three simulated source locations along the azimuth (-90, 0, and +90 degrees). Benefits of bilateral electrical stimulation were observed under conditions in which the speech and masker were spatially coincident and conditions in which they were spatially separated. Both the "head shadow" and "summation" effects were evident from the outset. Benefits consistent with "binaural squelch" were not reliably observed until 1 yr after implantation. These results support a growing consensus that bilateral implantation provides functional benefits beyond those of unilateral implantation. Longitudinal data suggest that some aspects of binaural processing continue to develop up to 1 yr after implantation. The squelch effect, often reported as absent or rare in previous studies of bilateral cochlear implantation, was present for most subjects at the 1 yr measurement interval.

Three‐year follow‐up of children with postmeningitic deafness and partial cochlear implant insertion

To evaluate the long-term outcome of children with postmeningitic deafness and partial insertion of the Nucleus electrode array, and to compare their speech perception performance with that of children with full insertion of the electrode array. A battery of seven speech perception tests was administered to 25 children with a cochlear implant (CI). Results were reduced into one score: equivalent hearing loss (EHL). Tertiary referral centre. The partial insertion group comprised seven children, mean age at implantation 5.5 years, mean duration of deafness 3.6 years. The full-insertion control group comprised 18 children. Mean age at implantation: 4.4 years; mean duration of deafness: 2.9 years. All the children became deaf between 0 and 3 years of age. Over a 3-year follow-up period, the children with partial insertion showed continuing progress, although there was wide variation in performance and the rate of progression. Some open-set comprehension could even be achieved with the insertion of only eight electrodes of a nucleus device. Three years after implantation, speech perception in the partial insertion children was poorer than that in the control groups with long (P < 0.01; 95% confidence interval 7-43 dB EHL) and short duration of deafness (P < 0.0001; 95% confidence interval 28-53 dB EHL). They showed slower progress and reached a poorer EHL plateau. Four of the seven children acquired open-set word recognition. Patients with partial insertion of the electrode array benefit from a CI, although less than patients with complete insertion.

Veränderungen der späten akustisch evozierten Potenziale bei postlingual ertaubten CI-Trägern

The speech recognition performances in postlingually deaf patients, which had a long duration of deafness, seem to be poorer than in patients with a short duration of deafness. The reason could be a functional reorganization in the auditory cortex. A long time of auditory deprivation may decrease neuronal activity in the auditory related cortices. As the late acoustically evoked potentials are generated in this region, we compared the speech recognition performances and also the late acoustically evoked potentials with the individual duration of deafness in a series of postlingually deaf patients. In 9 patients (cochlear implant (CI), MED EL) with postlingual deafness the late acoustically evoked potentials and the HSM-set-test on the quiet were measured. Additionally 1 patient with prelingual deafness was examined. The CI-operation was done, when he was 14 years old. The relations between the late acoustically evoked potentials and the speech recognition performances in dependence of the duration of deafness were examined. Typical late acoustically evoked potentials could be measured in 3 patients only. The speech recognition in these patients was very good. The longest time of deafness in these patients was 6 years. In 6 patients the minimum duration of deafness was 12 years. Here were measured the N1-potentials only, the P2- and the N2-potentials were absent. In these patients the scores of the HSM-set-test were lower than in the others. In the 15-years old patient with prelingual deafness the speech recognition was absent. The late acoustically evoked potentials of this patient showed an atypical form. The results of this study showed a correlation between the duration of deafness, the forms of the late acoustically evoked potentials and the speech perception. The duration of deafness preceding CI-implantation should be very small in deaf children and in postlingually deaf patients.

Predicting speech perception outcomes following cochlear implantation using Nottingham children’s implant profile (NChIP)

Background–Objective: Nottingham children’s implant profile (NChIP) is a systematic framework to assess deaf children before implantation taking into account not only the well-known factors (age, duration of deafness) but also family and support services, expectations, children’s cognitive abilities and learning style. The aim of the present paper is to assess the predictive value of the NChIP in the long-term outcomes of implanted children. Patients: This prospective and longitudinal study involved 51 profoundly deaf children, implanted within the same paediatric cochlear implant programme. All children were pre-lingually deaf with age at onset of deafness <2 years and age at implantation <6 years. Three and 4 years following implantation all children were assessed using two measures of speech perception. No child was lost to follow-up and no child was excluded from the study for any reason. Results: The most constant predictor of the outcomes was children’s learning style explaining upto 29% of the variance. Other significant predictors of the outcome were shorter duration of deafness, young age at implantation and family structure/support. Conclusions: Intrinsic factors in children and how well they communicate with their environment are of paramount importance to the outcome following implantation. The predictive value of NChIP has been demonstrated and the most important predictors of the outcome were children’s learning style, short duration of deafness, young age at implantation, and family structure/support.

Auditory brainstem implants: current neurosurgical experiences and perspective.

The objective of this study was to present aspects of the current treatment protocol, such as patient evaluation and selection for therapy, multimodality monitoring for optimal auditory brainstem implant (ABI) positioning and radiological evaluation, that might have an impact on the functional results of ABI. Out of a series of 145 patients with bilateral vestibular schwannomas 10 patients received an ABI, eight of which are reported here. Patient selection was based on disease course, clinical and radiological criteria (according to the Hannover evaluation and prognosis scaling of neurofibromatosis type 2 (NF2)), extensive otological test battery and psycho-social factors. ABI placement was controlled by multimodality electrophysiological monitoring in order to activate the auditory pathway and to prevent false stimulation of the cranial nerve nuclei or long sensory or motor tracts. Results of hearing function were correlated with patients' ages, duration of deafness, tumour extension, tumour-induced compression or deformation of the brainstem, and numbers of activated electrodes without any side-effects. Out of 59 patients with pre-operative deafness eight patients received an ABI of the Nucleus 22 type. All these patients became continuous users without any side effects and experienced improved quality of life. Speech reception in combination with lip-reading was markedly improved, with further improvement over a long period. A short duration of deafness may be favourable for achieving good results, while age was not a relevant factor. Lateral recess obstruction may necessitate a more meticulous dissection, but did not prevent good placement of the ABI in the lateral recess. Pre-existing brainstem compression did not prevent good results, but brainstem deformation and ipsi- and contralateral distortion were followed by a less favourable outcome. Among the factors that can be influenced by the therapy management are the selection of patients with a slow progressing NF2 disease, a short duration of deafness, a careful analysis of brainstem deformation and consideration of either side for implantation. Long-standing brainstem deformation might not lead to recovery, but instead lead to a low number of active electrodes and possibly only moderate results. ABI treatment is a safe procedure that can increase a patient's quality of life considerably. ABI placement along with neurophysiological control helps to prevent side effects and to improve acoustic activation. Further studies on structural and functional changes of the brainstem after previous tumour compression and distortion should increase our understanding and facilitate a decision on the best side for ABI implantation.

Introduction to cochlear implants

Cochlear implants have been very successful in restoring partial hearing to profoundly deaf people. Many individuals with implants are now able to communicate and understand speech without lip-reading, and some are able to talk over the phone. Children with implants can develop spoken-language skills and attend normal schools (i.e., schools with normal-hearing children). The greatest benefits with cochlear implantation have occurred in patients who (1) acquired speech and language before their hearing loss, and (2) have shorter duration of deafness. Gradual, but steady, improvements in speech production and speech perception have also occurred in prelingually deafened adults or children.