Acoustic analysis of the voice in pediatric cochlear implant recipients: a longitudinal study

OBJECTIVE: To characterize inherent acoustic abnormalities of the deaf pediatric voice and the effect of artificially restoring auditory feedback with cochlear implantation. DESIGN: Inception cohort. SETTING: Academic referral center. PATIENTS: Twenty-one children with severe to profound hearing loss (15 prelingually deaf, 6 postlingually deaf) accepted into the cochlear implant program were followed for up to 6 months. Patients unable to perform the vocal exercises were excluded. INTERVENTIONS: Objective voice analysis was performed using the Computerized Speech Laboratory (Kay Elemetrics) prior to cochlear implantation, at the time of implant activation and at 2 and 6 months postactivation. Assessments were based on sustained phonations and dynamic ranges. MAIN OUTCOME MEASURE: Fundamental frequency, long-term control of fundamental frequency (vF0) and long-term control of amplitude (vAM) were derived from sustained phonations. The dynamic frequency range was derived from scale exercises. Formant frequencies (F1, F2, F3) were determined using linear predictive coding. RESULTS: Fundamental frequency was not altered by implant activation or experience (P = 0.342). With profoundly deaf subject, the most prevalent acoustic abnormality was a poor long-term control of frequency (vF0, 2.81%) and long-term control of amplitude (vAm, 23.58%). Implant activation and experience had no effect on the long-term control of frequency (P = 0.106) but normalized the long-term control of amplitude (P = 0.007). The mean frequency range increased from 311.9 Hz preimplantation to 483.5 Hz postimplantation (P = 0.08). The F1/F2 ratio remained stable (P = 0.476). CONCLUSION: In children, severe to profound deafness results in poor long-term control of frequency and amplitude. Cochlear implantation restores control of amplitude only and implies the need for additional rehabilitative strategies for restoration of control of frequency.     

The influence of cochlear implantation on some voice parameters

OBJECTIVE: Some of the voice characteristics of deaf people differ considerably from those of speakers with normal hearing. After a cochlear implantation, auditory control of voice production is possible and the quality of the voice is improved. The aim of this study was to investigate the changes in some of the voice parameters in deaf children after cochlear implantation. METHODS: Thirty-one prelingually deafened children implanted unilaterally at the age of 2.5-13 years were included in the study. For all of the children an acoustic analysis (Multi-Dimensional Voice Program, Kay Elemetrics Corp., USA) of the Slovene vowel 'a' was performed before cochlear implantation and 6, 12 and 24 months after the implantation. The fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR) were compared before and after the implantation. The results of the acoustic analyses were compared for the children who were implanted before or at the age of 4 years and the children who were implanted after the age of 4 years. RESULTS: After the cochlear implantation the fundamental frequency did not change significantly. However, an improvement was noticed in the measurements of jitter (p=0.006) and shimmer (p=0.021) as early as 6 months after the implantation. The noise-to-harmonic ratio improved (p=0.013) 24 months after the implantation. The children implanted before or at the age of 4 years showed a significant improvement in jitter (p=0.003) and shimmer (p=0.004) as early as 6 months and in noise-to-harmonic ratio (p=0.021) 12 months after the implantation. In the children implanted after the age of 4 years the only significant change was detected in F0 (p=0.045), 12 months after the implantation, and in Shimmer (p=0.017), 24 months after the implantation. CONCLUSION: The results of the present study have confirmed that cochlear implantation enables auditory moment-to-moment control of pitch and loudness. The determination of jitter and shimmer in the vowel 'a' sample proved to be a good and early indicator of improved phonation control, even in young children. The deaf children who were implanted before the age of 4 years improved their voice control more quickly and to a greater extent than the children implanted after the age of 4 years.     

Altered phonatory physiology with short-term deactivation of children's cochlear implants.

OBJECTIVES: The purposes of this investigation were 1) to determine whether short-term auditory deprivation results in systematic phonatory changes for prelingually deafened children who use cochlear implants (CIs) and 2) to determine whether such changes are similar to those that have been reported for postlingually deafened adults. DESIGN: Participants were two 6-yr-old children with CIs. Both children had been prelingually deafened, had good to excellent speech production and speech perception skills, and had been using their CIs for 2.5 yr. A single-subject design was used. Intraoral air pressure (Po), phonatory air flow (Vl), electroglottograph (EGG) cycle width, fundamental frequency (F0), and intensity were measured during syllable production over two baseline days and three experimental days. Data were collected twice on each baseline day while the children wore their CIs, with a 1 hr break between data collection sessions. On experimental days, data were collected while the children wore their CIs (ON condition) and after their CIs had been removed for 1 hr (OFF condition). RESULTS: Both children demonstrated highly variable phonatory behaviors in baseline. The child with the more proficient speech production and perception skills showed consistent and significant reductions in Po, F0, and intensity in the OFF condition. These findings were dissimilar to those that occurred with repeated testing in the baseline condition and so were attributed to the sudden loss of auditory feedback. The other child showed a consistent and significant increase in mean Vl in the OFF condition. However, this child exhibited a similar finding with repeated testing in the baseline condition. Therefore, increased Vl in the OFF condition may have represented a practice effect. She also showed a small and consistent decrease in F0 in the OFF condition when F0 was derived from acoustic data, but this effect was not reliable in another data set when F0 was derived from the EGG signal. Our results with prelingually deafened children were inconsistent with reports of increased intensity and F0 in the absence of auditory feedback for postlingually deafened adults with CIs. CONCLUSIONS: Some prelingually deafened children who are successful CI users appear to use auditory feedback to self-monitor phonation. We suggest that the participant in our investigation who showed systematic phonatory changes in response to diminished auditory feedback was using auditory feedback primarily to stabilize her phonatory behaviors. She may not have had adequate experience with auditory feedback or adequate flexibility in her use of feedback mechanisms to implement the phonatory compensations that late-deafened adults use when auditory feedback suddenly is diminished. We further suggest that the phonatory changes that she exhibited during short-term auditory deprivation reflected disruption of her typical speaking strategies or apprehension about speaking when her ability to self-monitor auditorily was compromised.     

Cochlear implantation outcome in prelingually deafened young adults. A speech perception study

The outcome of cochlear implantation in patients with deafness of prelingual onset is largely unpredictable due to high individual variability. This study evaluated speech perception performances in a group of 18 prelingually deafened subjects (aged 13-30 years) which was homogeneous with respect to duration of deafness, hearing aid use before cochlear implantation, mode of communication and administration of auditory-oral speech therapy. Word discrimination length, word and sentence identification, phoneme identification and word and sentence recognition were tested before cochlear implantation and at 6 months, 1, 2 and 3 years of cochlear implant use. Scores on all tests significantly improved after cochlear implantation, although mean values were lower compared to those achieved by postlingually deafened patients. Speech performances on both word and sentence recognition continued to increase over time also beyond 1 year after cochlear implantation. Moreover, scores on sentence recognition tests were significantly higher compared to disyllabic words at 3 years of cochlear implant use. The presence of an auditory input delivered by hearing aids before cochlear implantation associated with auditory-oral therapy and a good level of education may positively influence the cochlear implant outcome in prelingually deafened adults.     

Changes of voice and articulation in children with cochlear implants

OBJECTIVE: The different speech sounds are formed by the primary voice signal and by the shape of the articulation tract. With this mechanism, specific overtones, the formants, are generated for each vowel. The objective of this study was to investigate the fundamental frequency (F0) of the voice signal and the first three formants (F1-F3) as a parameter of the articulation in prelingually deafened children at different timepoints after cochlear implantation (CI) compared with children with normal speech development. METHODS: Using the Kay CSL 4300B, the fundamental frequency and the formants F1-F3 of the Swiss-German vowel /a/ were investigated at different timepoints after CI in 20 prelingually deafened children aged 3.8-10.2 years by means of spectrographic and linear predictive coding (LPC) analysis. RESULTS: Children who had been operated before their fourth birthday showed no significant deviation in their fundamental frequency from age- and sex-matched peers, whereas a significant difference was documented in children who were older at the time of implantation. The first formant was very stable in every child and showed only discrete deviations from the normal range. The second and third formants, however, developed a broader scatter, but there was no systematic deviation of these formants to higher or lower values. The F1:F2 ratio was normal in children who were implanted at the age of up to 4 years and more centralized in children who were older at the time of implantation, as is known from the hearing impaired. CONCLUSIONS: Our results indicate that prelingually deaf children who receive a cochlear implant before their fourth birthday attain a better acoustic control over their speech, normalizing their fundamental frequencies and improving their articulatory skills.     

The additional hospital costs of the LAURA cochlear implant in the department of Otorhinolaryngology, Head and Neck Surgery of the University Hospital of Leuven

From the start of 1994 until 1996 ten patients (eight adults and two children) received cochlear implants after careful preoperative selection in our department. Only the deaf adults implanted with the LAURA cochlear implant were included in this retrospective analysis. In this study, the additional hospital costs associated with cochlear implantations were estimated. In doing this, a differentiation was made between ‘fixed’ costs and ‘variable’ costs. In general, the average cost of cochlear implantation was 1,186,741 BF (29,418.54 EUR) per implanted adult and a direct fixed cost of 262,880 BF (6,516.62 EUR) was needed for the computer requisites. In general, the cochlear implant enhance speech-perception scores in the postlingually deafened patients as well as in the prelingually deafened adults. After intensive training, all implanted adults of the University Hospital Leuven could recognize the segmental aspects of speech with scores above the level of significance. Received: 11 May 1998 / Accepted: 4 March 1999     

Analysis of outcomes for communication mode in cochlear implant in prelingually deafened adults

ObjectiveRecent studies have suggested that speech perception outcomes after cochlear implantation (CI) in prelingually deafened adults have improved with advances in CI technology and speech processing strategies. However, the outcomes vary from case to case. Communication mode has been reported in many studies as the factor that related to the post CI outcomes. This study aimed at investigating the post CI outcomes and the progress during 2 years for each communication mode.Material and MethodsThe subjects were 17 prelingually deafened adults undergoing CI at our hospital between April 2013 and March 2019. We investigated preoperative factors affecting post CI outcomes. Also we analyzed post CI outcomes for each communication mode and compared preoperative factors for each communication mode.ResultsCommunication mode and preoperative discrimination score were the factor affecting on postoperative discrimination score. The speech perception score after CI improved significantly in the oral and lip-reading group and total communication group. The speech perception scores in postlingually deafened adults improved significantly during the first six months and became to plateau after CI. On the other hand, the scores of prelingually deafened adults tended to improve gradually after six months postoperatively. Furthermore, the degree of improvement and progress differed by each communication mode.ConclusionThe communication mode is important factors in predicting outcomes in prelingually deafened adults after CI. Long-term auditory training is important for prelingually deafened adults who use visual information as their preoperative method of communication.     

Speech perception results--the first 10 years of a cochlear implant program

Long-term speech perception test results for prelingually deaf children were compared with those of postlingually deafened adults, both groups having undergone cochlear implant at our Center. Average open-set score results of adults were similar to those of the children. However, some qualitative differences were demonstrated on the perception of phonological contrasts between the groups.     

Early-deafened adult cochlear implant users: assessment of outcomes

OBJECTIVE: To determine whether adults deafened in the prelingual and perilingual stages of speech development realize objective and subjective benefits from cochlear implantation. METHOD: Retrospective analysis of the open-set speech recognition and subjective data such as use and quality of life. RESULTS: Between 1989 and 1999, 198 deafened adults underwent cochlear implantation at Sunnybrook and Women's College Health Sciences Centre. Of these, 44 patients were deafened pre- or perilingually. These subjects were implanted with a Nucleus 22, Nucleus 24 (Cochlear Corporation, Denver, Colorado, USA), or Clarion (Advanced Bionics Corporation, Sylmar, California, USA) device. The average age at implantation was 34 years (range 14-62 years). Significant differences in speech perception, as measured by a composite score of open-set word, phoneme, and sentence recognition, were found among groups who differed by type of education and communication training received in childhood. CONCLUSION: By and large, open-set speech recognition in prelingually and perilingually deafened adults is inferior to that achieved in postlingually deafened adults and varies according to the type of communication training they received. However, cochlear implants have significantly improved the overall communication skills and quality of life in all subgroups of patients.     

The relationship between the intraoperative ECAP threshold and postoperative behavioral levels: the difference between postlingually deafened adults and prelingually deafened pediatric cochlear implant users

The purpose of this study was to determine the relationship between electrically evoked compound-action potential (ECAP) thresholds, electrically evoked auditory brain-stem response (EABR) thresholds, behavioral thresholds (T levels) and maximum comfort levels (C levels) in profoundly deaf cochlear-implant users. The ECAP thresholds were measured intraoperatively in eight postlingually deafened adults and nine (eight prelingually and one postlingually deafened) children implanted with the Nucleus CI24 M cochlear implant. The mean ECAP thresholds did not differ between children and adults. The average behavioral T and C levels after at least 6 months of experience with a cochlear implant were significantly higher in children than those in adults. The ECAP thresholds were more strongly correlated with T and C levels in children than in adults. The stronger correlation between ECAP thresholds and behavioral T and C levels in children than in adults might result from differences in loudness sensation, which should in turn depend on auditory experience.     

Speech perception after cochlear implantation over a 4-year time period

OBJECTIVE: To evaluate the long-term speech perception of cochlear implantees and to compare the developing auditory performance patterns of prelingual children and postlingual deaf adults. MATERIAL AND METHODS: Twenty-nine prelingually deaf children and 17 postlingually deaf adults who had been followed up for 4 years were included in the study. Speech perception ability was assessed by means of vowel and consonant confusion tests and the Korean version of the Central Institute of Deafness (K-CID) test (performed without visual cues). The test results were analyzed at 3 and 6 months after implantation and then annually. RESULTS: In the prelingually deaf children, the average results continuously improved over the 4-year period. In the postlingually deaf adults, the average results did not improve further after the first 2 years. Individuals with < 5 years of deafness had a faster rate of recovery of speech perception than those who had been deaf for > 5 years. The K-CID scores were negatively correlated with age at implantation for the prelingually deaf group and with the duration of deafness in the postlingually deaf group. Children fitted with implants at a younger age showed better speech perception ability than those fitted with implants at an older age. Interestingly, prelingually deaf children aged 5-7 years at implantation showed the widest variation in individual outcomes. Amongst this group of children with highly variable outcomes, the metabolic status of brain cortices determined by means of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was available for three patients. The individual with the widest hypometabolic area had the best speech perception ability. CONCLUSION: The extent of hypometabolism as assessed by FDG-PET seemed to be one of the major factors predicting the outcome of cochlear implantation.     

Longitudinal changes in children's speech and voice physiology after cochlear implantation

OBJECTIVES: The purposes of this investigation were 1) to describe speech/voice physiological characteristics of prelingually deafened children before and after cochlear implantation and determine whether they fall into a range that would be considered deviant, 2) to determine whether selected deviant articulatory and phonatory behaviors of children with cochlear implants persist despite long-term cochlear implant use and continued participation in aural rehabilitation services, and 3) to determine whether further development of deviant articulatory and phonatory behaviors occurs postimplantation. DESIGN: Seven prelingually deafened children who received cochlear implants after 5 yr of age were followed from shortly before implantation until 5 to 6 yr postimplantation. These children received their early education in a Total Communication environment and used the Nucleus 22-electrode cochlear implant. All of them initially used the MPEAK speech processing strategy, and five of them eventually upgraded to the SPEAK speech processing strategy. Speech/voice physiological measurements that were obtained periodically from the children included intraoral air pressure (P(o)), nasal and phonatory air flow, voice onset time (VOT), and fundamental frequency (F(o)). Data from the deaf children were compared with a database from 56 children with normal hearing to determine when the deaf children exhibited "deviant" speech/voice behaviors. Speech/voice behaviors were considered "deviant" if they never occurred for children with normal hearing or were associated with z-scores that were outside the range of +/-2.0. RESULTS: The deaf children showed a wide range of deviant speech and voice behaviors both pre- and post-cochlear implant. The most frequently occurring atypical behaviors were use of negative P(o), high P(o) for [b, m], long and short VOT for [p], and high F(o). Some deviant behaviors improved post-cochlear implant. However, deviant behaviors often persisted for several years post-cochlear implant. There was considerable evidence of further development of deviant behaviors post-cochlear implant. All of the deaf children demonstrated deviancy on at least two of our measures at the last data collection interval (5 to 6 yr post-cochlear implant). CONCLUSIONS: Children who received cochlear implants after 5 yr of age and who were educated in a Total Communication setting showed persistence and further development of deviant speech/voice behaviors for several years post-cochlear implant. Although our findings cannot be generalized to other populations of children with cochlear implants (i.e., those who were implanted earlier, those educated in auditory-oral programs), it seems wisest at the present time not to assume that children's deviant speech/voice behaviors will remit spontaneously with continued cochlear implant use. Our data provide an important comparative database for future investigations of pediatric cochlear implant users who have had shorter periods of auditory deprivation and who have received cochlear implants with more current technological features. Longitudinal Changes in Children's Speech and Voice Physiology after Cochlear Implantation     

Chronological changes of stimulation levels in prelingually deafened children with cochlear implant

This study investigated changes in long-term cochlear implant MAPs (values of the program to stimulate electrodes) in children, and examined whether there were significant differences between children and adults. Ten prelingually deafened children (aged from 2.7 to 7.8 years) who received the Nucleus 22 cochlear implant at Kyoto University between 1996 and 1998 participated in this study. Behavioral thresholds (T levels) and maximal comfortable levels (C levels) were evaluated at 3 months post-implant, and then every 6 months up to 4 years. Ten adult cochlear implant users were also evaluated as a control group. All subjects had used their implant for at least 4 years after device connection. All prelingually deafened children demonstrated slower but continuous improvements in speech perception and production abilities during the test period. T levels became stable at 30 months post-implant in children and at 24 months post-implant in adults. C levels became stable at 6 months post-implant in children and within 3 months post-implant in adults. In conclusion, T levels of prelingually deafened children became stabilized 30 months post-implant, while C levels stabilized 6 months post-implant. MAPs of prelingually deafened children were stabilized 30 months post-implant, which was longer than that in adult cochlear implant users.     

Does the electrodes insertion depth influence speech rehabilitation progress in CI patients?

Many interdisciplinary teams from difference CI centers are studying speech rehabilitation process of implanted patients. Speech rehabilitation progress depend on many conditions like: duration of deafness, age at implantation, cause of deafness. Rehabilitation of postlingually deafened patients is very short. These subjects return very fast to the world of sounds. By the other side speech rehabilitation of prelingually deafened patients needs much more time (years). There are although well seen differences in language skills acquisition inside these groups. It confirmed, that speech rehabilitation after cochlear implantation could depends on others conditions as well. The aim of this study was electrodes insertion depth evaluation (cochleograms) and its influence on speech rehabilitation progress.     

Objective methods in postlingually and prelingually deafened adults for programming cochlear implants: ESR and NRT

This study compared responses of prelingually and postlingually deafened adult Nucleus 24 cochlear implant users on two objective measures employed to predict programming levels: neural response telemetry (NRT) and electrically evoked stapedial reflexes (eSR). Thirty experienced postlingually and prelingually deafened adult implant users underwent standard behavioural judgements of maximum comfortable loudness levels (C levels) and thresholds (Ts) followed by eSR and NRT measurements. Two different programs were created based on both the subjective judgement and the objective estimates of C levels (eSR thresholds) and these were compared. Relationships between the subjective and the objective measures were statistically analysed. Maximum stimulation levels estimated by both eSR and NRT were highly correlated with C levels. Variability of NRT results was higher than for eSR results. Mean NRT thresholds for postlingually deafened patients were higher than for prelingually deafened patients. A number of prelingually deafened users could distinguish no difference between programs; however, the majority of postlingually deafened users were sensitive to the difference and many reported preference for the program with eSR-estimated C levels. Neural response telemetry thresholds and eSRTs obtained in Nucleus 24 patients are highly correlated with C levels and Ts. Results suggest that estimation of C levels and Ts using NRT or eSR requires different correction factors for prelingually versus postlingually deafened adult subjects.     

Spatial hearing with a single cochlear implant in late-implanted adults

We assessed sound localisation abilities of late-implanted adults fitted with a single cochlear implant (CI) and examined whether these abilities are affected by the duration of implant use. Ten prelingually and four postlingually deafened adults who received a unilateral CI were tested in a sound-source identification task. Above chance performance was observed in those prelingual CI recipients who had worn their implant for longer time (9 years on average), revealing some monaural sound localisation abilities in this population but only after extensive CI use. On the contrary, the four postlingual recipients performed equal or better with respect to the best prelingual participants despite shorter experience with the monaural implant (11 months on average). Our findings reveal that some sound localisation ability can emerge in prelingually deafened adults fitted with a single implant, at least in a controlled laboratory setting. This ability, however, appears to emerge only after several years of CI use. Furthermore, the results of four postlingually deafened adults suggest that early experience with auditory cues may result in more rapid acquisition of spatial hearing with a single CI.     

Voice Discrimination by Adults with Cochlear Implants: the Benefits of Early Implantation for Vocal-Tract Length Perception

Cochlear implant (CI) users find it extremely difficult to discriminate between talkers, which may partially explain why they struggle to understand speech in a multi-talker environment. Recent studies, based on findings with postlingually deafened CI users, suggest that these difficulties may stem from their limited use of vocal-tract length (VTL) cues due to the degraded spectral resolution transmitted by the CI device. The aim of the present study was to assess the ability of adult CI users who had no prior acoustic experience, i.e., prelingually deafened adults, to discriminate between resynthesized “talkers” based on either fundamental frequency (F0) cues, VTL cues, or both. Performance was compared to individuals with normal hearing (NH), listening either to degraded stimuli, using a noise-excited channel vocoder, or non-degraded stimuli. Results show that (a) age of implantation was associated with VTL but not F0 cues in discriminating between talkers, with improved discrimination for those subjects who were implanted at earlier age; (b) there was a positive relationship for the CI users between VTL discrimination and speech recognition score in quiet and in noise, but not with frequency discrimination or cognitive abilities; (c) early-implanted CI users showed similar voice discrimination ability as the NH adults who listened to vocoded stimuli. These data support the notion that voice discrimination is limited by the speech processing of the CI device. However, they also suggest that early implantation may facilitate sensory-driven tonotopicity and/or improve higher-order auditory functions, enabling better perception of VTL spectral cues for voice discrimination.     

Cochlear implantation in prelingually deafened children with residual hearing

OBJECTIVE: The purpose of this study was to examine the speech perception skills of prelingually deafened French children with preoperative residual hearing who received multichannel cochlear implants. DESIGN: The design of the study incorporated a within-subject, repeated measures design for assessing speech perception skills. SETTING: Montpellier, Toulouse and Lyon Pediatric Cochlear Implant Centers. SUBJECTS: Seven prelingually deafened children demonstrating marginal benefit from conventional amplification prior to implantation with a Nucleus multichannel cochlear implant, served as subjects for the speech perception assessment (a speech recognition score less than 30% defines marginal benefit from acoustic amplification on open set materials). The mean age at implantation was 7 years, 9 months. OUTCOME MEASURES: Speech perception skills were assessed using open set materials and the MUSS and MAIS questionnaires. RESULTS: Open-set speech recognition averaged 21.4% before implantation, and 83.6% after 1 year's cochlear implant experience. All children demonstrated an open-set score over 60% after 12 months of CI use. MAIS test scores averaged 18.1/40 before implantation and 35.1/40 after 9 months of CI use. MUSS test scores averaged 24.4/40 before implantation and 34.1/40 after 9 months of CI use. CONCLUSIONS: Cochlear implantation should be considered for prelingually hearing impaired children demonstrating marginal benefit from hearing aids, with a speech recognition score less than 30% on open set materials, in order to improve their speech discrimination skills.     

Cochlear implantation on prelingually deafened adults

OBJECTIVE: To evaluate the validity of cochlear implantation (CI) on prelingually deafened adults who have been trained by auditory-verbal/oral communication since childhood. METHODS: Preoperative and postoperative data was investigated regarding the rehabilitation, hearing level, and educational experience of eight prelingually deafened adults. All eight patients were diagnosed with severe to profound sensorineural hearing loss (preoperative hearing levels were over 100 dB). All used hearing aids (HA) before the age of two and were trained by auditory-verbal/oral communication since childhood. The average age of the patients at the time of their CI operations was 23.3 ranging from 18 to 29 years of age. The average postoperative observation time was 55.4 months ranging from 11 to 90 months. RESULTS: Improvement was achieved not only on the pure-tone hearing threshold, but also in speech perception on tests using the Japanese video speech discrimination score (SDS) system. All of them now use CI very well in their daily lives and play important roles in society. CONCLUSION: It was demonstrated that even prelingually deafened adult patients could achieve considerable improvement through CI when they were trained well by auditory-verbal/oral communications since childhood. The indications of CI for prelingually deafened adults must be determined carefully, but all of them do not have to be rejected only because they are prelingually deafened. In other words, CI could be recommended for prelingually deafened adult patients if they received habilitation well with consistent auditory-verbal/oral training using well-fitted HAs.