Cochlear implantation in adults with prelingual deafness. Part II. Underlying constraints that affect audiological outcomes

Clinical characteristics and hearing loss etiology of cochlear implantees undergoing surgery in their teens, 20s, and 30s

PURPOSE

This study aimed to investigate the etiology of hearing loss, including genetic variants, in individuals who underwent cochlear implantation (CI) in their teens to thirties. It also sought to analyze post-CI speech performance and identify prognostic factors affecting CI outcomes in this age group.

METHODS

We conducted a retrospective review of 421 cochlear implant patients at Seoul National University Bundang Hospital, focusing on 63 subjects aged 10-39 years who underwent their first CI by a single surgeon between July 2018 and June 2022. The study included audiologic evaluation, molecular genetic testing, and analysis of speech performance post-CI. Statistical analyses were performed using SPSS 25 and GraphPad Prism 7.

RESULTS

Among 63 participants (M:F, 24:39), nine underwent CI in their teens, 24 in their 20 s, and 30 in their 30 s. Most of them (40, 63.5%) had postlingual deafness. The study found that 65.2% (40/63) of subjects received a genetic diagnosis, with DFNB4 being the most common etiology (37.5%, 15/40). Post-CI speech evaluation showed an average sentence score of 80% across all subjects. Factors such as the onset of hearing loss, duration of deafness (DoD), and preoperative Speech Intelligibility Rating (SIR) significantly influenced CI outcomes. Notably, longer DoD was associated with poorer CI outcomes, but this did not affect individuals with postlingual hearing loss as much.

CONCLUSION

The study concludes that in individuals aged 10-39 undergoing CI, the onset of hearing loss and preoperative SIR are critical predictors of postoperative outcomes. CI is recommended for those with postlingual hearing loss in this age group, irrespective of the DoD. The study highlights the importance of genetic factors especially DFNB4 in hearing loss etiology and underscores the value of the relatively easy-to-evaluate factor, preoperative SIR in predicting CI outcomes.

Impact of superior semicircular canal dehiscence on cochlear implant audiologic outcomes

PURPOSE

Determine whether adult cochlear implant users with radiographic superior semicircular canal dehiscence experience clinically significant differences in audiological outcomes when compared to cochlear implant users with normal temporal bone anatomy.

MATERIALS AND METHODS

Retrospective, single institution review. Adult, post-lingual deaf patients implanted between 2010 and 2020. Inclusion criteria included age 18 years or older, available preoperative computed tomography imaging, and preoperative and postoperative AzBio audiological data for at least 6 months of cochlear implant use. Preoperative and postoperative AzBio Sentence Test scores were compared between patients with normal temporal bone anatomy and those with radiographic superior semicircular canal dehiscence or near dehiscence.

RESULTS

110 patients met inclusion criteria. Mean AzBio score for normal temporal bone anatomy group improved from 35.2 % (SD 28.2) preoperatively to 70.3 % (SD 25.7) postoperatively, an improvement of 35.1 % (SD 28.6). Mean AzBio score for near dehiscent temporal bone anatomy group improved from 26.6 % (SD 28.9) preoperatively to 64.5 % (SD 30.6) postoperatively, an improvement of 37.9 % (SD 27.9). Mean AzBio score for dehiscent temporal bone anatomy group improved from 26.3 % (SD 20.4) preoperatively to 65.1 % (SD 27.6) postoperatively, an improvement of 38.7 % (SD 26.9). Utilizing the one-way analysis of variance test, there was no significant difference in audiologic outcomes between the three groups.

CONCLUSIONS

Patients with complete or near complete radiographic superior canal dehiscence at the time of cochlear implantation achieve similar improvements in speech perception scores compared to normal anatomy adult cochlear implant users.

Benefits of auditory-verbal intervention for adult cochlear implant users: perspectives of users and their coaches

OBJECTIVE

Post-implant rehabilitation is limited for adult cochlear implant (CI) recipients. The objective of this research was to capture the perspectives of CI users and their coaches regarding their experiences with auditory-verbal intervention as an example of post-implant rehabilitation and their views on perceived benefits and challenges related to the intervention.

DESIGN

This qualitative study involved semi-structured focus group interviews with adult CI users and their coaches who accompanied them in a 24-week auditory-verbal intervention program.

STUDY SAMPLE

A total of 17 participants (eight CI users and nine coaches) contributed to the interviews.

RESULTS

Three key topic areas emerged from the interviews capturing CI users' and coaches' experiences related to the intervention program: (1) benefits of the intervention, (2) factors affecting experiences, and (3) challenges and barriers. Benefits included increased confidence in hearing, communication, social participation, and new knowledge about technology and hearing. Factors affecting the experience were participants' motivation and the therapist's skills. The primary challenge was the time commitment for weekly therapy.

CONCLUSIONS

Both CI users and coaches perceived a focussed auditory-verbal intervention to be beneficial in improving speech understanding, confidence in using hearing, social interaction, and knowledge about technology. Participants recommended reducing the intensity of intervention to facilitate participation.

Cochlear implant in prelingually hearing-impaired adults: prognostic factors and results

Objectives

The aim of present study is to evaluate the impact of prognostic factors on the outcome in a group of prelingually hearing-impaired patients submitted to cochlear implantation (CI) at an adult age.

Methods

This is a retrospective study on a cohort of prelingually severe-to-profound hearing-impaired patients cochlear implanted in adulthood and followed by a single audiology centre. We correlated post-CI results in term of speech perception with patients’ speech perception with hearing aids before implantation, history of progression of hearing loss (HL), and levels of education and cognition. The study group was composed of 49 patients.

Results

Post-CI open-set recognition score in silence and noise was significantly correlated with pre-CI open-set recognition score in silence and with background noise. Patients with a history of progression of HL gained significantly better results. Furthermore, we found higher improvements in patients with a higher level of education.

Conclusions

Prelingually deafened patients implanted in adulthood achieved satisfactory results. Significantly better results were achieved by patients with better pre-operative speech perception scores, progressive HL and higher level of education.

The Effect of Monaurally Fitted Hearing Aid Use on the Evolution of Presbycusis

OBJECTIVE

The effect of hearing aid use on the evolution of presbycusis has not been well described in the literature, with only a handful of publications addressing this topic. This paper aims to evaluate the long-term use of amplification and its effect on pure-tone thresholds and word recognition scores.

METHOD

Monaurally fitted patients were followed with serial audiograms. Data was collected from hearing aid centers. Seventy-seven patients with presbycusis met the inclusion criteria and participated in the present study. The progression of hearing loss in both pure tone thresholds and word recognition scores were compared between the hearing aid ears (HA), and the non-hearing aid ears (NHA). Pure tone thresholds were analyzed by comparing the pure tone average at the initial and last audiograms. Word Recognition Scores (WRS) were analyzed using the model of Thornton and Raffin (1978), and by comparing the change in the absolute values of WRS from the initial to the last audiogram between the HA ear and the NHA ear.

RESULTS

No significant difference in pure-tone thresholds between the HA ear and NHA ear was found at the last audiogram (P = .696), even after dividing the patients into groups based on the duration of amplification. Both methods of analysis of patients' WRS showed a statistically significant worsening in NHA (P < .05).

CONCLUSION

The present study supports the previously defined auditory deprivation effect on non-fitted ears, which showed worsening of word recognition over time and no effect on pure tone average. It provides an additional argument for the counseling of patients with presbycusis considering amplification, and highlights the importance of bilateral amplification in preserving the residual hearing of hearing impaired patients.

Acoustic and Aerodynamic Analyses of the Voice of Prelingually Deaf Young Men After Cochlear Implantation

OBJECTIVE

The purpose of this study was to characterize the acoustic and aerodynamics of the voice of young men with prelingual deafness after cochlear implantation (CI) to provide a theoretical basis for their rehabilitation after CI.

METHODS

The CI group included 17 young men with prelingual deafness who implanted cochlear at 18-24 years old. The control group included 17 normally hearing young men at the same age. The 10-item Voice Handicap Index, acoustic parameters, and aerodynamic parameters were evaluated.

RESULTS

For the acoustic parameters, the F0, SDF0, and Jitter of the CI group were higher than those of the Control group, and these differences were statistically significant. Additionally, The difference in mean shimmer and mean NHR values between the CI group and the Control group was not statistically significant For the aerodynamic parameters, the subglottal pressure and aerodynamic power of the CI group were significantly higher than those of the Control group, whereas the MPT was significantly shorter.

DISCUSSION

Due to excessive stress on the laryngeal muscle and limited pneumo-phono-articulatory coordination, the young men in the CI group had a thin voice and poor voice control and muscle coordination, and they exhibited excessive laryngeal resistance. We propose that after CI, in addition to regular hearing and speech rehabilitation, voice training is also extremely important for prelingually deaf young men.

The use of the MUSS and the SIR scale in late-implanted prelingually deafened adolescents and adults as a subjective evaluation

Background: The SIR scale has been widely used to measure speech improvement in late-implanted prelingually deafened adolescents and adults. However the ceiling effect of the SIR scale may lead to the loss of some information.Aim/objectives: To evaluate the oral ability of late-implanted prelingually deafened adolescents and adults using the MUSS and SIR scale and to analyse the relationship between the SIR score and the MUSS score.Material and methods: Ninety-four prelingually deafened adolescents and adults who had received cochlear implants were investigated. The MUSS and SIR scale were used to evaluate oral ability.Results: The relationship between the duration of implant use and the MUSS score was significantly different. No significant differences were found among the groups for age at implantation, gender and side of cochlear implantation. The total score on the MUSS was positively correlated with the SIR score.Conclusions and significance: The MUSS and the SIR scale could be used to evaluate the oral ability of late implanted patients. The SIR scale could be used to perform a rapid assessment and the MUSS could help provide more information. The combination of the two scales could be used to evaluate vocal ability more accurately and effectively.

Early Deafened, Late Implanted Cochlear Implant Users Appreciate Music More Than and Identify Music as Well as Postlingual Users

Introduction: Typical cochlear implant (CI) users, namely postlingually deafened and implanted, report to not enjoy listening to music, and find it difficult to perceive music. Another group of CI users, the early-deafened (during language acquisition) and late-implanted (after a long period of auditory deprivation; EDLI), report a higher music appreciation, but is this related to a better music perception?

Materials and Methods: Sixteen EDLI and fifteen postlingually deafened (control group) CI users participated in the study. The inclusion criteria for EDLI were: severe or profound hearing loss onset before the age of 6 years, implantation after the age of 16 years, and CI experience more than 1 year. Subjectively, music perception and appreciation was evaluated using the Dutch Musical Background Questionnaire. Behaviorally, music perception was measured with melodic contour identification (MCI), using two instruments (piano and organ), each tested with and without a masking contour. Semitone distance between successive tones of the target varied from 1 to 3 semitones.

Results: Subjectively, the EDLI group reported to appreciate music more than postlingually deafened CI users. Behaviorally, while clinical phoneme recognition test score on average was lower in the EDLI group, melodic contour identification did not significantly differ between the two groups. There was, however, an effect of instrument and masker for both groups; the piano was the best-recognized instrument, and for both instruments, the masker with non-overlapping pitch was best recognized.

Discussion: EDLI group reported higher appreciation of music than postlingual control group, even though behaviorally measured music perception did not differ significantly between the two groups. Both surprising findings since EDLI CI users would be expected to have lower outcomes based on the early deafness onset, long duration of auditory deprivation, and on average lower clinical speech scores. Perhaps, the music perception difficulty comes from similar electric hearing limitations in both groups. The higher subjective appreciation in EDLI might be due to the lack of a musical memory, with no ability to compare music heard via the CI to acoustic music perception. Overall, our findings support a benefit from implantation for a positive music experience in EDLI CI users.

Application of auditory cortical evoked potentials for auditory assessment in people using auditory prosthesis

The present study explored the application of auditory cortical evoked potentials (ACEP) in the auditory assessment of people using an auditory prosthesis. There were 126 patients with prelingual deafness who were selected from January 2012-June 2017 from the First People's Hospital of Kunshan (Kunshan, China). HEARLab™ system was used to induce a P1-N1-P2 waveform under the condition of 60 dB sound pressure level at /m/, /g/ and /t/ acoustic stimulations. Speech production ability and auditory perception ability of patients were evaluated by speech intelligibility rating (SIR) and categories of auditory performance (CAP). Extraction rate of P1 waves of patients with auditory prosthesis was higher than that of N1 and P2 waves under different acoustic stimulations. A younger initial age and shorter deafness duration before patients used an auditory prosthesis led to more marked P1-N1-P2 waveforms and longer P1 latencies. At /m/ acoustic stimulation, P1 latency and amplitude were negatively associated with the usage time of auditory prosthesis. There were significant differences in the results of SIR and CAP and the initial age of use of auditory prosthesis and deafness duration before patients used the auditory prosthesis. These findings suggest that ACEP can be used to evaluate the auditory assessment of people using an auditory prosthesis. The initial age of use of an auditory prosthesis and deafness duration can affect the P1-N1-P2 waveform and P1 latency of prelingual deafness.

Cochlear implant in prelingually deafened oralist adults: speech perception outcomes, subjective benefits and quality of life improvement

The aim of this study is to report our results in a group of prelingually deafened adults, who followed an oralist rehabilitation programme, and submitted to cochlear implant at our institution. We evaluated 30 prelingually deafened adult patients, 18 males and 12 females, median age 35 years, of a group of 36 prelingually deafened adult patients consecutively submitted to unilateral cochlear implantation at the ENT Unit of the University of Pisa. After implantation, patients achieved significant benefits in terms of speech perception skills, including the ability to have telephone conversations in some cases, quality of life and their own perception of disability. According to literature data, the results herein reported are quite variable but generally satisfactory. Procedures other than traditional speech perception measures should be used to evaluate the benefits of cochlear implant in such patients, to compressively evaluate the global benefits, not only in terms of speech perception, but also in terms of quality of life and daily life.

Intelligibility of the Patient's Speech Predicts the Likelihood of Cochlear Implant Success in Prelingually Deaf Adults

OBJECTIVES

The objective of this study was to determine the validity and clinical applicability of intelligibility of the patient's own speech, measured via a Vowel Identification Test (VOW), as a predictor of speech perception for prelingually deafened adults after 1 year of cochlear implant use. Specifically, the objective was to investigate the probability that a prelingually deaf patient, given a VOW score above (or below) a chosen cutoff point, reaches a postimplant speech perception score above (or below) a critical value. High predictive values for VOW could support preimplant counseling and implant candidacy decisions in individual patients.

DESIGN

One hundred and fifty-two adult cochlear implant candidates with prelingual hearing impairment or deafness took part as speakers in a VOW; 149 speakers completed the test successfully. Recordings of the speech stimuli, consisting of nonsense words of the form [h]-V-[t], where V represents one of 15 vowels/diphthongs ([(Equation is included in full-text article.)]), were presented to two normal-hearing listeners. VOW score was expressed as the percentage of vowels identified correctly (averaged over the 2 listeners). Subsequently, the 149 participants enrolled in the cochlear implant selection procedure. Extremely poor speakers were excluded from implantation, as well as patients who did not meet regular selection criteria as developed for postlingually deafened patients. From the 149 participants, 92 were selected for implantation. For the implanted group, speech perception data were collected at 1-year postimplantation.

RESULTS

Speech perception score at 1-year postimplantation (available for 77 of the 92 implanted participants) correlated positively with preimplant intelligibility of the patient's speech, as represented by VOW (r = 0.79, p < 0.00001): the more intelligible the patient's speech, the higher the predicted postimplant speech perception score. This correlation is explained by the hypothesis that the two variables have a common driving force, i.e., (in)adequacy of auditory speech input in the earliest years of life. With a 60% cutoff point, VOW can discriminate between individuals with "above-chance" postimplant speech perception and those with "chance level" postimplant speech perception with sensitivity and specificity of 0.84 and 0.86, respectively. The probability that a patient with a VOW score ≥ 60% achieves "above-chance" speech perception after implantation is 0.91. Conversely, the probability that a patient with VOW < 60% reaches "above-chance" speech perception is 0.25.

CONCLUSIONS

For prelingually deaf adults, intelligibility of the patient's speech-as represented by VOW-is a valid predictor of postimplant speech perception. A patient with a VOW score above a preset cutoff is much more likely to develop acceptable speech perception after implantation than a patient with a VOW score below that cutoff. The binary classification based on VOW and the associated probabilities of cochlear implant success in terms of speech perception can be used-in addition to existing criteria-to support the clinician in guiding patient expectations and in considering implant candidacy for individual patients.

Sensitivity of expressive linguistic domains to surgery age and audibility of speech in preschoolers with cochlear implants

OBJECTIVES

To determine whether relative delays among domains exist in the conversational use of vocabulary, syntax, and morphology by children with cochlear implants (CIs) and whether these were differentially affected by age of implantation (AOI) and the audibility of speech.

METHODS

Participants in this short-term longitudinal study were 126 children with AOI of 6-38 months and a matched group of 30 children without hearing loss. Language samples of the same children at ages 3.5 and 4.5 were analyzed for the breadth of vocabulary and bound morphemes used, and sentence length.

RESULTS

At both test ages, expressive language domains were delayed equally. Higher performance across domains was independently associated with younger AOI and better pre-implant-aided thresholds. No domain was affected differently by very early implantation, but bound morpheme breadth was associated with better CI-aided thresholds. Between 63 and 78% of children with AOI of 6-11 months scored close to hearing age-mates by 4.5, a level achieved by fewer than 25% of those with AOI of 19-24 months or later ages.

DISCUSSION

Previous studies indicated greater language delays in the areas of morphology and syntax than those of vocabulary, with the earliest ages of implantation conferring the greatest benefit to those domains. The current design addressed inconsistency across studies in modes of communication used, presence/absence of other disabilities, and differences in language domains chosen as outcome measures.

CONCLUSIONS

Linguistic domains benefitted equally from early implantation, regardless of the duration of auditory stimulation. Better pre-CI-aided hearing often compensated for later AOI. Bound morpheme use was greater with better CI-aided thresholds.

The effects of early auditory-based intervention on adult bilateral cochlear implant outcomes

OBJECTIVES

The goal of this exploratory study was to determine the types of improvement that sequentially implanted auditory-verbal and auditory-oral adults with prelingual and childhood hearing loss received in bilateral listening conditions, compared to their best unilateral listening condition.

METHODS

Five auditory-verbal adults and five auditory-oral adults were recruited for this study. Participants were seated in the center of a 6-loudspeaker array. BKB-SIN sentences were presented from 0° azimuth, while multi-talker babble was presented from various loudspeakers. BKB-SIN scores in bilateral and the best unilateral listening conditions were compared to determine the amount of improvement gained.

RESULTS

As a group, the participants had improved speech understanding scores in the bilateral listening condition. Although not statistically significant, the auditory-verbal group tended to have greater speech understanding with greater levels of competing background noise, compared to the auditory-oral participants.

DISCUSSION

Bilateral cochlear implantation provides individuals with prelingual and childhood hearing loss with improved speech understanding in noise. A higher emphasis on auditory development during the critical language development years may add to increased speech understanding in adulthood. However, other demographic factors such as age or device characteristics must also be considered.

CONCLUSION

Although both auditory-verbal and auditory-oral approaches emphasize spoken language development, they emphasize auditory development to different degrees. This may affect cochlear implant (CI) outcomes. Further consideration should be made in future auditory research to determine whether these differences contribute to performance outcomes. Additional investigation with a larger participant pool, controlled for effects of age and CI devices and processing strategies, would be necessary to determine whether language learning approaches are associated with different levels of speech understanding performance.

PET-CT observations of cortical activity in pre-lingually deaf adolescent and adult patients with cochlear implantation

CONCLUSIONS

The present study yielded useful information concerning pre-lingually deaf adolescents and adults who try or manage to understand languages. PET-CT can provide insights into brain plasticity and elucidate which mode of communication is the most effective for education of such patients.

OBJECTIVES

To study the cortical activity in pre-lingually deaf adolescent and adult cochlear implants (CI) users who have been trained in auditory-verbal/oral communication since childhood.

METHODS

Using positron emission tomography (PET) and 18F-fluorodeoxyglucose (FDG), brain activities in six pre-lingually and two post-lingually deaf CI users (mean age at CI surgery = , 20.3 years; three males, five females) were compared with those of 10 normal age-matched controls (mean age = 27.1 years). Regional cerebral blood flow changes were measured during an acoustic presentation of a story.

RESULTS

In compliant CI users, the number of hypermetabolic auditory-related areas was greater in those who had a CI in their 20s than in those who did so in their adolescence. In poor and non-compliant users, hypermetabolism was not seen in the auditory association area, but in the primary auditory areas (BA41) and the Broca's area (BA45). In post-lingually deaf CI users, no increase in the number of hypermetabolic areas was found in auditory-related regions.

Cochlear implantation outcomes in children with common cavity deformity; a retrospective study

Objective

A common cavity deformity (CCD) is a deformed inner ear in which the cochlea and vestibule are confluent forming a common rudimentary cystic cavity that results in profound hearing loss. There are few studies paying attention to common cavity. Our group is engrossed in observing the improvement of auditory and verbal abilities in children who have received cochlear implantation (CI), and comparing these targets between children with common cavity and normal inner ear structure.

Material and methods

A retrospective study was conducted in 12 patients with profound hearing loss that were divided into a common cavity group and a control group, six in each group matched in sex, age and time of implantation, based on inner ear structure. Categories of Auditory Performance (CAP) and speech intelligibility rating (SIR) scores and aided hearing thresholds were collected and compared between the two groups. All patients wore CI for more than 1 year at the Cochlear Center of Anhui Medical University from 2011 to 2015.

Results

Postoperative CAP and SIR scores were higher than before operation in both groups (p < 0.05), although the scores were lower in the CCD group than in the control group (p < 0.05). The aided threshold was also lower in the control group than in the CCD group (p < 0.05).

Conclusion

Even though audiological improvement in children with CCD was not as good as in those without CCD, CI provides benefits in auditory perception and communication skills in these children.

[The results of cochlear implantation in the patient with hereditary and non-hereditary hearing loss]

The objective of the present study was to evaluate the effectiveness of rehabilitation of the patients after cochlear implantation in the early and late periods after operation taking into consideration the etiology of congenital deafness. The comprehensive clinico-audiological examination performed during the period from 2010 to 2015 involved 246 children who had undergone cochlear implantation (CI). All children were operated at the National Research Center for Audiology and Hearing Rehabilitation in the period from 2003 to 2013. 83 (56%) patients were aged 1 to 3 years at the time of surgery. Their age varied from 3 to 18 years when they underwent the clinico-audiological examination. Thus, the study is based on the experience with cochlear implantation varying from 3 to 12 years. The genetic analysis revealed mutations in the GJB2 gene in 49% of the children, in agreement with the data of earlier studies. 85% of all the children with GJB2 deafness surgically treated at the age under 4 years attend ordinary institutions of learning. Within 24 months after the onset of the observations the majority of the children with hereditary deafness (63%) were referred to the groups with good and excellent results of the rehabilitation and only 6 (12%) patients presented with unsatisfactory results. It was shown that the acquired causes of the loss of hearing including severe prenatal pathology have a negative influence on the long-term outcomes of rehabilitation. The results of the genetic analysis for the elucidation of the cause of impaired hearing can be employed as a prognostic criteria not only for the prediction but also for the guarantee of the success of cochlear implantation provided the rehabilitative process was initiated in a proper time.

Factors Affecting Speech Perception Improvement Post Implantation in Congenitally Deaf Adults

OBJECTIVES

To identify factors preimplantation associated with postimplantation speech perception improvement in the adult congenitally deaf population.

DESIGN

Forty-four adult cochlear implant (CI) patients who had a severe to profound hearing loss from birth were identified from this centre's database. Eight preimplantation factors, speech intelligibility, preimplantation hearing levels, communication mode, preimplantation speech perception scores, progression of hearing loss, age at implantation, hearing aid use preimplantation, and gender, were recorded during the CI assessment process. These factors were investigated to determine their effect on speech perception improvement postimplantation. The outcome measures were the improvement in scores for the BKB Sentence test and CUNY Sentence test with lipreading after implantation. In the final analysis, 26 patients were included in the CUNY analysis, and 30 patients were included in the BKB analysis.

RESULTS

Speech intelligibility rating, preimplantation hearing levels, and communication mode were shown to be significantly associated with improvements in speech perception postimplantation.

CONCLUSION

Three factors were identified that affected speech perception improvement postimplantation: speech intelligibility, preimplantation hearing levels, and communication mode. These factors can be used to counsel CI patients regarding potential speech perception improvements from cochlear implantation, although these are based on average data and may not reflect individual performance.

Trials of a Contralateral Hearing Aid After Long-Term Unilateral Cochlear Implant Use in Early-Onset Deafness

PURPOSE

The purpose of this study was to evaluate the practicability of binaural hearing by adding a contralateral hearing aid (HA) after long-term cochlear implant (CI) use in prelingually deaf adults.

METHOD

Five individuals with 1 CI volunteered for a 3-week bimodal (CI + HA) trial. HA gain was set low until sound was tolerable, then increased as listeners acclimated. Participants logged their daily listening experiences and were closely monitored by the audiologist. Measures included pre- and posttrial consonant-nucleus-consonant (CNC) word and phoneme scores and self-reports of satisfaction and listening ability in difficult situations.

RESULTS

Acoustic stimulation was initially unpleasant, but approached comfort at target gain within the 3-week period. Benefit was demonstrated in continued voluntary HA use and higher bimodal phoneme scores compared to CI alone (8%-31% increases) for 4 of the participants.

CONCLUSIONS

When a second CI is not a consideration, a contralateral HA should be pursued as the standard of care for prelingually deaf adults despite substantial auditory deprivation in the previously unaided ear, unpleasant sensations at initial HA fit, or lack of dramatic objective test gains. Frequent audiologist contact, repeated HA adjustments, and client journals are valuable in promoting favorable outcomes with bimodal hearing (adaptation, acceptance, and benefit) for this population.

Receptive language as a predictor of cochlear implant outcome for prelingually deaf adults

OBJECTIVE

This study investigated outcomes and predictive factors, specifically language skills, for a group of prelingually hearing-impaired adults who received a cochlear implant.

DESIGN

Speech perception data, demographic information, and other related variables such as communication mode, residual hearing, and receptive language abilities were explored. Pre- and post-implant speech perception scores were compared and multiple regression analysis was used to identify significant predictive relationships.

STUDY SAMPLE

The study included 43 adults with a prelingual onset of hearing loss, who proceeded with cochlear implantation at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia.

RESULTS

The majority of patients experienced benefit from their cochlear implants, with 88% demonstrating significant improvement in speech perception performance. Volunteers achieved better post-operative speech perception scores if they had a shorter duration of severe-to-profound hearing loss, better language skills, and used an exclusively oral communication mode.

CONCLUSIONS

Although post-operative speech perception performance is significantly poorer for prelingually hearing-impaired adults compared to postlingually hearing-impaired patients, the study group demonstrated significant benefit from their cochlear implants. The variability in post-operative outcomes can be predicted to some extent from the hearing history and language abilities of the individual patient.

Differential activity in Heschl's gyrus between deaf and hearing individuals is due to auditory deprivation rather than language modality

Sensory cortices undergo crossmodal reorganisation as a consequence of sensory deprivation. Congenital deafness in humans represents a particular case with respect to other types of sensory deprivation, because cortical reorganisation is not only a consequence of auditory deprivation, but also of language-driven mechanisms. Visual crossmodal plasticity has been found in secondary auditory cortices of deaf individuals, but it is still unclear if reorganisation also takes place in primary auditory areas, and how this relates to language modality and auditory deprivation. Here, we dissociated the effects of language modality and auditory deprivation on crossmodal plasticity in Heschl's gyrus as a whole, and in cytoarchitectonic region Te1.0 (likely to contain the core auditory cortex). Using fMRI, we measured the BOLD response to viewing sign language in congenitally or early deaf individuals with and without sign language knowledge, and in hearing controls. Results show that differences between hearing and deaf individuals are due to a reduction in activation caused by visual stimulation in the hearing group, which is more significant in Te1.0 than in Heschl's gyrus as a whole. Furthermore, differences between deaf and hearing groups are due to auditory deprivation, and there is no evidence that the modality of language used by deaf individuals contributes to crossmodal plasticity in Heschl's gyrus.

Long-term asymmetric hearing affects cochlear implantation outcomes differently in adults with pre- and postlingual hearing loss

In many countries, a single cochlear implant is offered as a treatment for a bilateral hearing loss. In cases where there is asymmetry in the amount of sound deprivation between the ears, there is a dilemma in choosing which ear should be implanted. In many clinics, the choice of ear has been guided by an assumption that the reorganisation of the auditory pathways caused by longer duration of deafness in one ear is associated with poorer implantation outcomes for that ear. This assumption, however, is mainly derived from studies of early childhood deafness. This study compared outcomes following implantation of the better or poorer ear in cases of long-term hearing asymmetries. Audiological records of 146 adults with bilateral hearing loss using a single hearing aid were reviewed. The unaided ear had 15 to 72 years of unaided severe to profound hearing loss before unilateral cochlear implantation. 98 received the implant in their long-term sound-deprived ear. A multiple regression analysis was conducted to assess the relative contribution of potential predictors to speech recognition performance after implantation. Duration of bilateral significant hearing loss and the presence of a prelingual hearing loss explained the majority of variance in speech recognition performance following cochlear implantation. For participants with postlingual hearing loss, similar outcomes were obtained by implanting either ear. With prelingual hearing loss, poorer outcomes were obtained when implanting the long-term sound-deprived ear, but the duration of the sound deprivation in the implanted ear did not reliably predict outcomes. Contrary to an apparent clinical consensus, duration of sound deprivation in one ear has limited value in predicting speech recognition outcomes of cochlear implantation in that ear. Outcomes of cochlear implantation are more closely related to the period of time for which the brain is deprived of auditory stimulation from both ears.

Delayed prelingual cochlear implantation in childhood and puberty

OBJECTIVE

To evaluate the results of delayed cochlear impantion performed in childhood and puberty in the light of speech language pathology assessments.

METHODS

Totally 49 children with prelingual profound hearing loss were included in the study. All children received a cochlear implant between the ages of 5 and 19 years (Group 1 aged between 5 and 9 years, group 2 aged between 10 and 14 years, group 3 aged between and 15 and 19 years). The MAIS, MUSS and PLS-4 scores of children were evaluated one month before, and one year and two years after the operation. The descriptive statistics included several independent variables; age of implantation; gender; trade name of the implant; preoperative duration of hearing aid use; preoperative special education, family support and additional handicap. These variables were categorical variables. We used repeated measures analysis of variance to test improvements in MAIS, MUSS and PLS scores, and whether this improvement depend on the independent variables. In addition, we also tested the interaction between time and the independent variables.

RESULTS

The preoperative MAIS, MUSS and language scores were significantly higher in older children compared to younger children (p<0.01). After two years these scores were similar between the all age groups (p>0.4). There was a significant age and time interaction (p=0.005). That is, improvement continued in all age groups in a parallel way and group 2 reached to the level of group 1 after two years. However, group 3 almost reached to a plateau level after two years. The family support was associated with the MAIS, MUSS and language scores of the patients (p=0.01), and there was a family support-time interaction (p<0.0001). In group 1 and 2, the way of communication shifted from total communication (lip reading, sign language, auditory) to auditory-verbal communication in a significant number of the patients (p<0.01). However, that change in the way of communication was not statistically significant in group 3 (p>0.05).

CONCLUSION

The decision of delayed cochlear implantation in children can be made in the light of following parameters. A good family support is most important. The patients must be wearing hearing aids regularly since early childhood, and preferably use the auditory verbal communication. Evaluation of the patient with MAIS, MUSS and PLS is important to understand the level of receptive and expressive communication level.

Cochlear implantation in late-implanted prelingually deafened adults: changes in quality of life

BACKGROUND

With expanding inclusion criteria for cochlear implantation, the number of prelingually deafened persons who are implanted as adults increases. Compared with postlingually deafened adults, this group shows limited improvement in speech recognition. In this study, the changes in health-related quality of life in late-implanted prelingually deafened adults are evaluated and related to speech recognition.

METHODS

Quality of life was measured before implantation and 1 year after implantation in a group of 28 prelingually deafened adults, who had residual hearing and who used primarily oral communication. Patients completed 3 questionnaires (Nijmegen Cochlear Implant Questionnaire, Glasgow Benefit Inventory, and Health Utility Index 3). Postoperative scores were compared with preoperative scores. Additionally, phoneme recognition scores were obtained preimplantation and 1 year postimplantation.

RESULTS

Quality of life improved after implantation: scores on the Nijmegen Cochlear Implant Questionnaire improved significantly in all subdomains (basic speech perception, advanced speech perception, speech production, self-esteem, activity, and social interaction), the total Glasgow Benefit Inventory score improved significantly, and the Health Utility Index 3 showed a significant improvement in the utility score and in the subdomains "hearing" and "emotion." Additionally, a significant improvement in speech recognition scores was found. No significant correlations were found between gain in quality of life and speech perception scores.

CONCLUSION

The results suggest that quality of life and speech recognition in prelingually deafened adults significantly improved as a result of cochlear implantation. Lack of correlation between quality of life and speech recognition suggests that in evaluating performance after implantation in prelingually deafened adults, measures of both speech recognition and quality of life should be used.

Cortical auditory evoked potentials in unsuccessful cochlear implant users

In some cochlear implant users, success is not achieved in spite of optimal clinical factors (including age at implantation, duration of rehabilitation and post-implant hearing level), which may be attributed to disorders at higher levels of the auditory pathway. We used cortical auditory evoked potentials to investigate the ability to perceive and discriminate auditory stimuli in 10 unsuccessful implant users aged 8-10 years (CI) and 10 healthy age-matched controls with normal hearing (NH). Pure tones (1 and 2 kHz) and double consonant-vowel syllables were applied. The stimuli were presented in an oddball paradigm that required the subjects to react consciously. The latencies and amplitudes of the P1, N1, P2, N2 and P3 waves were analyzed, in addition to reaction times and number of responses. Significant differences in the average response times and number of responses were observed between the CI and NH groups. The latencies also indicate that the CI group took longer to perceive and discriminate between tonal and speech auditory stimuli than the NH group.

Speech intelligibility as a predictor of cochlear implant outcome in prelingually deafened adults

OBJECTIVES

Among adult patients with prelingual deafness, interindividual variability in speech perception outcome after cochlear implantation is generally large. It was hypothesized that the intelligibility of the patient's own speech may be predictive of speech perception with a cochlear implant. The objectives were (1) to provide a validation of a new test battery as a measurement tool for intelligibility using a group of prelingually deafened patients; (2) to investigate the validity of the test battery as a predictor of postimplant speech perception, based on preliminary data with a cochlear implant from a subgroup of patients; and (3) to investigate the validity of the test battery as a predictor of postimplant health-related quality of life (HRQoL) for the same subgroup of patients.

DESIGN

Twenty-five adult cochlear implant candidates with prelingual deafness participated in this study. Average age at onset of deafness was 8 mos (range 0 to 4 yrs). Speech samples from the participants were recorded and presented to two normal-hearing listeners. Results from the seven intelligibility tests in the battery were subjected to analyses of reliability and validity. Furthermore, the multiple test outcomes were submitted to a Principal Component Analysis to investigate the possibility of summarizing the data. Subsequently, from the group of 25 participants, 9 participants with above-average intelligibility were selected for implantation. Speech perception data with a cochlear implant from the nine implantees were collected at 12 mos postimplantation, as well as HRQoL data. Predictive validity of the intelligibility test battery was determined, using the postimplant data as the criterion.

RESULTS

Results from the 25 participants averaged over listeners showed that all tests in the battery had good reliability and validity as measures of intelligibility. Principal Component Analysis showed that the multiple test outcomes could be summarized by a single underlying variable. Despite the early age at onset of deafness, the subgroup of nine participants who received a cochlear implant included several good performers in terms of speech perception with the implant. The intelligibility test battery summary score had good validity as a predictor of postimplant outcome: the more intelligible the participant's speech, the better his or her speech perception outcome with the cochlear implant. Availability of effective auditory input in early life may be the fundamental factor underlying the potential for speech perception with a cochlear implant in later life. The intelligibility test battery can be reduced to a single test to minimize testing time without negatively affecting its predictive validity. Predictive validity of the intelligibility test battery can be generalized to HRQoL outcomes of cochlear implantation, provided these outcomes are concerned with speech processing abilities.

CONCLUSIONS

The new test battery (or its reduced version), used as a measure of intelligibility, is a promising tool for guiding cochlear implant candidacy decisions and counseling for individual patients with prelingual deafness. Because intelligibility has superior predictive power in comparison to age at onset of deafness, the latter should be discarded as an exclusion criterion for cochlear implantation.

Observation of cortical activity during speech stimulation in prelingually deafened adults with cochlear implantation by positron emission tomography-computed tomography

OBJECTIVES

We evaluated the cortical activity of 2 successful prelingually deafened adult cochlear implant (CI) users who have been trained by auditory-verbal/oral communication since childhood.

METHODS

Changes in regional cerebral blood flow were measured by positron emission tomography using '8F-fluorodeoxyglucose while the subjects were receiving auditory language stimuli by listening to a story. Ten normal-hearing volunteers were observed as age-matched control subjects.

RESULTS

In both cases, the auditory-related regions, when compared to same regions in the control subjects, showed hypermetabolism in the left dorsolateral prefrontal cortex and the left precentral gyrus--similar to that in successful CI users who are prelingually deafened children or postlingually deafened adults. Both subjects had the ability to activate these areas, and this ability might be one of the reasons that accounts for such exceptionally good performance in older prelingually deaf CI users. As for the visual-related regions, hypometabolism was observed in Brodmann areas 18 and 19, and this finding might be related to the intensive auditory-verbal/oral education that the subjects had received since childhood.

CONCLUSIONS

Despite the limits imposed by the small sample size and the spatial resolution of positron emission tomography, this study yielded insights into the nature of the brain plasticity in prelingually deafened adults who are successful CI users.

Delayed cochlear implantation in adults with prelingual severe-to-profound hearing loss

OBJECTIVES

To evaluate the results of late cochlear implantation in prelingually deaf patients with significant residual hearing loss and to evaluate patient factors relevant to postoperative auditory outcomes in this patient group.

STUDY DESIGN

Analysis of results of cochlear implantation using postoperative speech perception test scores per each condition.

SETTING

Tertiary referral center.

PATIENTS

Thirty-two subjects with severe to profound hearing loss that developed before the age of 4.

INTERVENTIONS

Subjects were implanted at a mean age of 24.8 years (range, 16-44) with Nucleus CI24 (n = 18, 56%), Clarion HiRes 90K (n = 11, 34%), and Medel PULSA (n = 3, 10%) device. Details of etiology, duration of deafness, hearing aid history, hearing thresholds before operation, communication mode, and educational environment were investigated. Speech perception tests were performed preoperatively and 12 months after the operation.

MAIN OUTCOME MEASURES

Postoperative speech perception test scores between different options within patient group.

RESULTS

: The results showed significant improvement in open set speech perception (sentence) scores after the implantation (mean scores from 7.0 to 46.7, p < 0.05). Preoperative hearing of better ear and preoperative speech perception scores correlated with postoperative performances (r = -0.70 and r = 0.46, respectively, p < 0.05). Education and communication mode were also closely related to postoperative performances. In the group with poorer performances, preoperative hearing thresholds were significantly worse than those with better performances, and a larger portion of those patients attended special schools and used sign language.

CONCLUSION

We found that residual auditory capacity in the better ear is an important factor in predicting outcomes after cochlear implantation in patients with prelingual hearing loss.

Cochlear implantation in patients with bilateral cochlear trauma

PURPOSE

Temporal bone fracture, which involves the otic capsule, can lead to complete loss of auditory and vestibular functions, whereas the patients without fractures may experience profound sensorineural hearing loss due to cochlear concussion. Cochlear implant is indicated in profound sensorineural hearing loss due to cochlear trauma but who still have an intact auditory nerve.

MATERIAL AND METHODS

This is a retrospective review study. We report 5 cases of postlingually deafened patients caused by cochlear trauma, who underwent cochlear implantation. Preoperative and postoperative hearing performance will be presented. These patients are cochlear implanted after the cochlear trauma in our department between 2001 and 2006.

RESULTS

All patients performed very well with their implants, obtained open-set speech understanding. They all became good telephone users after implantation. Their performance in speech understanding was comparable to standard postlingual adult patients implanted.

CONCLUSION

Cochlear implantation is an effective aural rehabilitation in profound sensorineural hearing loss caused by temporal bone trauma. Preoperative temporal bone computed tomography, magnetic resonance imaging, and promontorium stimulation testing are necessary to make decision for the surgery and to determine the side to be implanted. Surgery could be challenging and complicated because of anatomical irregularity. Moreover, fibrosis and partial or total ossification within the cochlea must be expected.

Cochlear implantation in adolescents with prelinguistic deafness

Objective: The aims of this study were to examine auditory function in a group of adolescents with prelingual deafness who received cochlear implants (CI) and to identify poor-outcome predictors in order to define reliable prognostic indicators useful in selecting patients for CI.

Study Design: Prospective study.

Setting: The study was conducted in the Audiology Unit of Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.

Subjects and Methods: The study involved 45 adolescents (mean age at implantation: 13.4 ± 2.6 years, range: 11-18) with profound congenital hearing impairment with a follow-up of three years. Preimplantation and postimplantation auditory performance and speech perception were evaluated using the mean score of three hearing and speech perception tests (vowel-consonant-vowel [VCV], identification of disyllabic words, and recognition of short sentences) performed in auditory-only listening conditions.

Results: Significant improvements in all speech perception tests were observed after CI. However, 15 cases were considered “poor performers” (i.e., the auditory performance of these patients was less than 30 percent). The diagnosis of deafness in these subjects was significantly delayed (18.07 ± 6.25 and 34.4 ± 10.26 months in good and poor performers, respectively, P = 0.006), and their hearing threshold was significantly lower than in the good users group. The mean age at CI was 12.8 ± 2.33 and 14.53 ± 2.70 years in good and poor performers, respectively ( P = ns).

Conclusion: CI was shown to be a useful device with the ability to reverse the adverse consequences of hearing loss, particularly for prelingual adolescents who receive implantation early in life and who present a hearing threshold of 100 dB or better both at diagnosis and at surgery.

Transfer of auditory perceptual learning with spectrally reduced speech to speech and nonspeech tasks: implications for cochlear implants

OBJECTIVE

The objective of this study was to assess whether training on speech processed with an eight-channel noise vocoder to simulate the output of a cochlear implant would produce transfer of auditory perceptual learning to the recognition of nonspeech environmental sounds, the identification of speaker gender, and the discrimination of talkers by voice.

DESIGN

Twenty-four normal-hearing subjects were trained to transcribe meaningful English sentences processed with a noise vocoder simulation of a cochlear implant. An additional 24 subjects served as an untrained control group and transcribed the same sentences in their unprocessed form. All subjects completed pre- and post-test sessions in which they transcribed vocoded sentences to provide an assessment of training efficacy. Transfer of perceptual learning was assessed using a series of closed set, nonlinguistic tasks: subjects identified talker gender, discriminated the identity of pairs of talkers, and identified ecologically significant environmental sounds from a closed set of alternatives.

RESULTS

Although both groups of subjects showed significant pre- to post-test improvements, subjects who transcribed vocoded sentences during training performed significantly better at post-test than those in the control group. Both groups performed equally well on gender identification and talker discrimination. Subjects who received explicit training on the vocoded sentences, however, performed significantly better on environmental sound identification than the untrained subjects. Moreover, across both groups, pre-test speech performance and, to a higher degree, post-test speech performance, were significantly correlated with environmental sound identification. For both groups, environmental sounds that were characterized as having more salient temporal information were identified more often than environmental sounds that were characterized as having more salient spectral information.

CONCLUSIONS

Listeners trained to identify noise-vocoded sentences showed evidence of transfer of perceptual learning to the identification of environmental sounds. In addition, the correlation between environmental sound identification and sentence transcription indicates that subjects who were better able to use the degraded acoustic information to identify the environmental sounds were also better able to transcribe the linguistic content of novel sentences. Both trained and untrained groups performed equally well ( approximately 75% correct) on the gender-identification task, indicating that training did not have an effect on the ability to identify the gender of talkers. Although better than chance, performance on the talker discrimination task was poor overall ( approximately 55%), suggesting that either explicit training is required to discriminate talkers' voices reliably or that additional information (perhaps spectral in nature) not present in the vocoded speech is required to excel in such tasks. Taken together, the results suggest that although transfer of auditory perceptual learning with spectrally degraded speech does occur, explicit task-specific training may be necessary for tasks that cannot rely on temporal information alone.

Cochlear implants and spoken language processing abilities: review and assessment of the literature

Cochlear implants (CIs) process sounds electronically and then transmit electric stimulation to the cochlea of individuals with sensorineural deafness, restoring some sensation of auditory perception. Many congenitally deaf CI recipients achieve a high degree of accuracy in speech perception and develop near-normal language skills. Post-lingually deafened implant recipients often regain the ability to understand and use spoken language with or without the aid of visual input (i.e. lip reading). However, there is wide variation in individual outcomes following cochlear implantation, and some CI recipients never develop useable speech and oral language skills. The causes of this enormous variation in outcomes are only partly understood at the present time. The variables most strongly associated with language outcomes are age at implantation and mode of communication in rehabilitation. Thus, some of the more important factors determining success of cochlear implantation are broadly related to neural plasticity that appears to be transiently present in deaf individuals. In this article we review the expected outcomes of cochlear implantation, potential predictors of those outcomes, the basic science regarding critical and sensitive periods, and several new research directions in the field of cochlear implantation.

Behavioral and electrophysiological measures of auditory change detection in children following late cochlear implantation: a preliminary study

OBJECTIVE

The purpose of the current study was to longitudinally assess the development of automatic sound feature discrimination and compare it to behavioral discrimination in late-implanted cochlear implant users.

METHODS

Scalp-recorded auditory evoked potentials (AEPs) and behavioral discrimination of frequency, duration and intensity differences within an oddball paradigm using complex stimuli were recorded in three late-implanted cochlear implant subjects beginning on turn-on day.

RESULTS

Variable results were obtained in behavioral and AEPs that were consistent with the amount of pre-implant auditory experience each subject had. The best user showed rapid development of neurophysiologic indices of change detection along with improvement in behavioral and real-world auditory skills. In contrast, there were no recordable AEPs in the poorer CI user and there was little change in behavioral outcomes.

CONCLUSION

There is evidence of utilization of usual auditory processing pathways in the AEPs of some children who receive cochlear implants late in their childhood. Some plasticity in the auditory cortical pathways may be present despite prolonged auditory deprivation in school-aged children who are late-implanted cochlear implant recipients.

What can be expected from a late cochlear implantation?

OBJECTIVE

Verify if late cochlear implantation allows pre-lingual deafs to convert from visual to oral communication mode only.

METHOD

Thirteen pre-lingual profoundly deaf patients implanted the ages of 8 and 22 years were included in the study. Before cochlear implantation, none of the patients used the oral language. Six patients used cued speech and seven used the sign language to communicate. Evaluations were made with measures of hearing thresholds, phoneme identification, categories of auditory performance and rating of the intelligibility of speech before and after implantation. Changes in principal mode of communication (i.e. oral, cued speech or sign language) were also monitored.

RESULTS

The former users of cued speech benefited significantly more from cochlear implantation than the sign language users for phoneme identification and categories of auditory performance, although all had similar hearing thresholds before and after cochlear implantation. After a mean implant use of 4.5 years, four out of six cued speech users converted to exclusive use of the oral language, while only one out of seven former users of the sign language converted to the use of the oral language.

DISCUSSION

It is possible for pre-lingual or congenital deafs to convert totally from a visual to an oral communication mode even in case of late cochlear implantation. Previous awareness of the structure of the oral language, even without hearing (e.g. via cued speech) influences positively the outcome of delayed implantations. We recommend the adoption of oral communication with the cued speech code in cases where a late cochlear implantation is envisioned.

Cochlear Implant Outcomes and Quality of Life in Adults with Prelingual Deafness

OBJECTIVES

To evaluate sound and speech perception and quality of life in prelingually deafened adults implanted with state of the art devices. To investigate which patient factors influence postoperative performance.

STUDY DESIGN

Prospective intervention study.

METHODS

Eight prelingually deafened subjects (with onset of severe hearing impairment before the age of 4 years and functioning in an oral-aural setting) participated in this study. Subjects were implanted at a mean age of 36 (range, 21-55) years with a CII or 90 K cochlear implant (Advanced Bionics Corp.). All subjects completed standard speech perception tests as well as quality of life measures (Health Utility Index Mark-II, Nijmegen Cochlear Implant Questionnaire, visual analogue scale for subject's hearing and health) at different points in time. Postoperative scores were compared with each other and with the baseline preoperative scores. The relationship between nine patient variables and the postoperative consonant-vowel-consonant (CVC) phoneme score was also investigated.

RESULTS

Significant improvement was measured for CVC word and phoneme scores and several quality of life measures. Postoperative speech perception correlated with a new and promising factor named quality of a patient's own speech production (QoSP).

CONCLUSION

With state of the art implants, speech perception and quality of life do improve in prelingually deafened adults. More importantly, the prognostic value of QoSP should be investigated further.

Otosclerosis

OBJECTIVES

1. To examine whether speech perception after implantation is correlated with the total duration of deafness, the duration of deafness in the implanted ear, or age at implantation. 2. To examine whether the rate of facial nerve stimulation postoperatively is correlated with the type of electrode used.

STUDY DESIGN

Retrospective case note review.

SETTING

Tertiary referral center.

PATIENTS

Fifty-nine adults with profound postlingual sensorineural hearing loss due to otosclerosis.

INTERVENTION

Cochlear implantation with the Nucleus device using either a straight (n = 35) or Contour (n = 29) electrode array.

MAIN OUTCOME MEASURES

Speech perception scores for patients at 3, 6 and 12 months postimplantation were correlated against duration of deafness in the implanted ear, duration of total deafness, and age at implantation. Data on facial nerve stimulation rates postoperatively were collected.

RESULTS

Implantation in the shortest deafened ear conferred an initial advantage for speech perception 3 months after surgery; however, this effect was lost by 6 months. There were no significant correlations between the duration of bilateral deafness and hearing outcomes. Age at implantation was negatively correlated with outcome at 3 months, but not at 6 and 12 months. Fourteen of 35 patients with straight electrodes and 0 of 24 patients with Contour electrodes experienced facial nerve stimulation during mapping sessions (p < 0.005, chi).

CONCLUSION

Patients with otosclerosis are not disadvantaged in the long term by implantation in the longest deafened ear. Increasing age at implantation did not predict poorer outcomes. A perimodiolar design of electrode should be used in otosclerotic patients when possible to reduce the risk of facial nerve stimulation.

Development of Pre-Word-Learning Skills in Infants with Cochlear Implants

Families of infants who are congenitally deaf now have the option of cochlear implantation at a very young age. In order to assess the effectiveness of early cochlear implantation, however, new behavioral procedures are needed to measure speech perception and language skills during infancy. One important component of language development is word learning-a complex skill that involves learning arbitrary relations between words and their referents. A precursor to word learning is the ability to perceive and encode intersensory relations between co-occurring auditory and visual events. Recent studies in infants with normal hearing have shown that intersensory redundancies, such as temporal synchrony, can facilitate the ability to learn arbitrary pairings between speech sounds and objects (Gogate & Bahrick, 1998). To investigate the early stages of learning arbitrary pairings of sounds and objects after cochlear implantation, we used the Preferential Looking Paradigm (PLP) to assess infants' ability to associate speech sounds to objects that moved in temporal synchrony with the onset and offsets of the signals. Children with normal hearing ranging in age from 6, 9, 18, and 30 months served as controls and demonstrated the ability to learn arbitrary pairings between temporally synchronous speech sounds and dynamic visual events. Infants who received their cochlear implants (CIs) at earlier ages (7-15 months of age) performed similarly to the infants with normal hearing after about 2-6 months of CI experience. In contrast, infants who received their implants at later ages (16-25 months of age) did not demonstrate learning of the associations within the context of this experiment. Possible implications of these findings are discussed.