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

In patients with some residual hearing and minor benefit from conventional hearing aids, the benefits of cochlear implantation have to be weighed carefully against eventual adverse effects. In this study, pre- and post-operative thresholds as well as functional results after cochlear implantation are reported; 17 of 44 implanted adults had residual hearing pre-operatively (mean threshold(250 to 4000 Hz): 106 dB HL) in the implanted ear. Residual hearing in the implanted ear could not, in general, be preserved post-operatively. Seventeen of 44 implanted children had some amount of residual hearing in the implanted ear pre-operatively (implanted ear: 114 dB HL; contralateral ear: 109.9 dB HL; mean thresholds(250 to 4000 Hz))). Contrary to the results in adults, residual hearing in the implanted ear remained statistically unchanged. Hearing in the contralateral ear increased significantly from 109.9 to 101.9 dB HL post-operatively. This increase was mainly attributed to maturation of the central auditory pathway. In adults with residual hearing, the monosyllable word recognition scores increased significantly from 9 per cent pre-operatively to 42 per cent post-operatively. Children with residual hearing tended to perform better on speech-related test material compared to children without prior auditory experience. Cochlear implantation is indicated in adults and children with residual hearing and minor benefit from conventional amplification. The contralateral ear in children should be considered for additional acoustical stimulation.     

Cochlear implants: selection criteria and shifting borders

Cochlear implants have proven to be effective and reliable in postlingually deaf adults. This is also true for congenitally deaf and perilingually deaf children up to the age of six years. Due to the increasing experience, the improvement of implant technology and the proven reliability the selection criteria are broadened with shifting borders. The main extensions are related to age, additional handicaps, residual hearing and special etiologies of deafness. Increasing evidence shows that very early implantation results in better performance and better hearing and speech development. Near-normal language acquisition can be achieved in children implanted under the age of four. Additional handicaps do not automatically exclude a candidate from cochlear implantation. A case-to-case decision has to be made based on additional diagnostics and the experience of the implant centre. A list of suitable handicaps is provided. Severely hearing impaired patients may also be considered for cochlear implantation if their residual hearing provides no benefit for speech discrimination. The same holds true for children. Cochlear implantation in obliterated cochleae and inner ear malformation requires a special surgical technique and special electrode arrays. In this way even difficult cases can be managed with remarkable outcome. Over all, the selection criteria have been broadened with increasing experience and technological improvement. This development may continue and the borderline between hearing aids and cochlear implants will shift further towards severe hearing loss. However, the basis for success still remains good rehabilitation, a team approach and the willingness of the patient to undergo the whole process of cochlear implantation.     

Reliability of monosyllabic discrimination tests in white noise for differentiating among hearing aids

In spite of criticism, monosyllabic discrimination tests are widely employed for hearing aid selection. The current study was designed to investigate the following questions: (1) How reliable is aided speech discrimination of monosyllables in a background of white noise? (2) Can differences among hearing aids be reliably demonstrated by measuring intelligibility of monosyllables in a background of white noise? and (3) Do hearing aids interact with hearing loss? Twenty subjects with mild-moderate sensorineural hearing losses participated in two experimental sessions. Four hearing aids were evaluated using the NU-6 monosyllables in a background of white noise (s/n = +20 dB). Since the standard deviation of the test-retest differences was 6%, differences between aids were not considered significant unless they exceeded 12%. An interaction between subjects and hearing aids was found; that is, the best aid for one person was not the best for all. Measuring monosyllabic word intelligibility in a background of white noise does not reliably identify a single best aid. However, one or more inferior aids were consistently eliminated in 80% of the subjects.     

Improvements in speech perception by children with profound prelingual hearing loss: effects of device, communication mode, and chronological age

The present investigation expanded on an earlier study by Miyamoto, Osberger, Todd, Robbins, Karasek, et al. (1994) who compared the speech perception skills of two groups of children with profound prelingual hearing loss. The first group had received the Nucleus multichannel cochlear implant and was tested longitudinally. The second group, who were not implanted and used conventional hearing aids, was tested at a single point in time. In the present study, speech perception scores were examined over time for both groups of children as a function of communication mode of the child. Separate linear regressions of speech perception scores as a function of age were computed to estimate the rate of improvement in speech perception abilities that might be expected due to maturation for the hearing aid users (n=58) within each communication mode. The resulting regression lines were used to compare the estimated rate of speech perception growth for each hearing aid group to the observed gains in speech perception made by the children with multichannel cochlear implants. A large number of children using cochlear implants (n=74) were tested over a long period of implant use (m=3.5 years) that ranged from zero to 8.5 years. In general, speech perception scores for the children using cochlear implants were higher than those predicted for a group of children with 101-110 dB HL of hearing loss using hearing aids, and they approached the scores predicted for a group of children with 90-100 dB HL of hearing loss using hearing aids.     

The assembly of Ni2+-actin: some peculiarities

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

Predictive factors for speech perception in patients with cochlear implant

Cochlear implant therapy is an epoch-making advance in artificial sensory organ transplants, but the positive effects on speech perception vary. Quantification theory type I, a multivariate analysis, was used to determine predictive factors for speech perception in patients with cochlear implants. Fifty-one postlingual deaf adults (18 male and 33 female, mean age, 53.4, mean duration of deafness, 8.6 years) were tested for speech perception three or more months after a Nucleus 22 channels cochlear implant. The cause of deafness in nine patients was labyrinthitis, ototoxicity in five, meningitis in three and unknown in the remaining 34. Speech perception was measured by vowel, consonant and word recognition using a live voice, and monosyllable, word and sentence recognition using a videodisc. All tests were administered in a sound only condition. Results of the univariate analysis indicated that age at implantation was correlated with monosyllable recognition, and duration of deafness was correlated with live voice word recognition. Residual hearing and coding strategy were both correlated with all outcome measures. The multivariate analysis revealed that coding strategy, duration of deafness, residual hearing and the number of electrodes were significant predictors of live voice word recognition in that order.     

Preferred CDRH3 lengths for antibodies with defined specificities

OBJECTIVES/HYPOTHESIS: To compare early (<1 y) and longer-term (1.0-7.5 y; mean follow-up, 2.8 y) hearing results following surgery for congenital aural atresia and to analyze revision cases for cause of failure, time of occurrence, and outcome. STUDY DESIGN: Retrospective study of 55 consecutive patients (59 ears) undergoing surgery during an 11-year period for congenital aural atresia. METHODS: The best speech reception threshold (SRT) during the first postoperative year was compared with the most recent SRT beyond the first postoperative year. The complication rate and long-term hearing results (>1 y) for initial and revision surgeries were compared. RESULTS: In the early postoperative period, an SRT of < or =25 dB was achieved in 60% and an SRT of < or =30 dB in 70%. With longer follow-up (mean, 2.8 y), 46% of patients maintained an SRT < or =25 dB. Revision surgery was necessary in approximately one third of patients. Longer-term hearing results following initial surgery only or after revision surgery showed an SRT < or =25 dB in 53% and an SRT < or =30 dB in 64%. For primary and revisions surgeries the incidence of temporary facial paralysis was 1.5% and for significant hearing loss, 3.0%. CONCLUSIONS: Some degradation in hearing does occur as patients are followed beyond the first postoperative year. Revision surgery will be necessary in approximately one third of cases. With revisions, an SRT < or =25 dB can be expected in half of cases and an SRT < or =30 dB in two thirds of cases. The ability to provide these hearing results supports this surgery in unilateral cases.     

Noise-induced hearing loss in young adults: the role of personal listening devices and other sources of leisure noise

CONCEPT: No consensus exists regarding the magnitude of the risk of noise-induced hearing loss (NIHL) associated with leisure noise, in particular, personal listening devices in young adults. OBJECTIVE: Examine the magnitude of hearing loss associated with personal listening devices and other sources of leisure noise in causing NIHL in young adults. STUDY DESIGN: Prospective auditory testing of college student volunteers with retrospective history exposure to home stereos, personal listening devices, firearms, and other sources of recreational noise. METHODS: Subjects underwent audiologic examination consisting of estimation of pure-tone thresholds, speech reception thresholds, and word recognition at 45 dB HL. RESULTS: Fifty subjects aged 18 to 30 years were tested. All hearing thresholds of all subjects (save one-a unilateral 30 dB HL threshold at 6 kHz) were normal, (i.e., 25 dB HL or better). A 10 dB threshold elevation (notch) in either ear at 3 to 6 kHz as compared with neighboring frequencies was noted in 11 (22%) subjects and an unequivocal notch (15 dB or greater) in either ear was noted in 14 (28%) of subjects. The presence or absence of any notch (small or large) did not correlate with any single or cumulative source of noise exposure. No difference in pure-tone threshold, speech reception threshold, or speech discrimination was found among subjects when segregated by noise exposure level. CONCLUSION: The majority of young users of personal listening devices are at low risk for substantive NIHL. Interpretation of the significance of these findings in relation to noise exposure must be made with caution. NIHL is an additive process and even subtle deficits may contribute to unequivocal hearing loss with continued exposure. The low prevalence of measurable deficits in this study group may not exclude more substantive deficits in other populations with greater exposures. Continued education of young people about the risk to hearing from recreational noise exposure is warranted.     

Macrolides in the management of streptococcal pharyngitis/tonsillitis

OBJECTIVE: This study aimed to compare the hearing changes in the long term after vestibular neurectomy, endolymphatic mastoid shunt, and medical treatment in classic Meniere's disease. STUDY DESIGN: A retrospective case review was conducted based on audiologic follow-up between 5 and 21 years. SETTING: The study was performed at two centers in Bari University Hospital, one performing vestibular neurectomy as the first surgical procedure for Meinere's disease and the other, endolymphatic mastoid shunt. PATIENTS AND INTERVENTIONS: Of 68 patients with intractable idiopathic Meniere's disease, 29 underwent middle fossa vestibular neurectomy, and 17 had endolymphatic mastoid shunt; 22 were offered surgery but declined. MAIN OUTCOME MEASURES: Outcome measures were puretone average (PTA), speech reception threshold, and speech discrimination score before and after treatment. RESULTS: PTA declined by an average of 9.3 dB in neurectomy patients, 13.3 dB in patients undergoing endolymphatic mastoid shunt, and 18.1 dB in patients who were offered surgery but declined. Patients were subdivided into two cohorts based on their preoperative or initial PTA. In the patients who had PTA scores worse than 50 dB initially, the PTA declined an average of 4.3 dB in the vestibular neurectomy group, 11.5 dB in the endolymphatic sac group, and 4 dB in the nonsurgical group. In the patients with PTA > or = 50 dB initially, the PTA declined an average of of 25.3 dB in the vestibular neurectomy group, 16.1 in the endolymphatic sac group, and 26.2 dB in the nonsurgical group. Although shunt patients with good hearing initially deteriorated less than neurectomy patients and less than patients who declined surgery, the difference was not significant. CONCLUSIONS: These results indicate that patients with poor hearing stabilized, while patients with good hearing continued to deteriorate. The same conditions were observed in the patients who had surgery and those who were offered surgery but declined.     

A new quadruple therapy for the eradication of Helicobacter pylori. Effect of pretreatment with omeprazole on the cure rate

The aim of the study was to assess the speech discrimination ability of postlingually deaf adults implanted with the Combi 40 cochlear implant and to compare the results with the postoperative data published for other devices. The postoperative open and closed set speech perception performance of 21 consecutive patients was tested using a standardized test battery comprising a number, monosyllable, sentence, consonant and vowel discrimination test as well as a rhyme test in the sound only condition. Mean values achieved for each test 1, 6 and 12 months after "switch on" were evaluated. The results demonstrate that all patients have a substantial benefit from their implant and show a continuous improvement in their speech perception abilities with increased device experience. The mean percentages of correct answers after 12 months were 93.4 for numbers, 44.6 for monosyllables, 78.5 for sentences, 67.6 for the rhyme test, 59.8 for vowel, and 67.3 for consonant discrimination. Preoperatively, the mean discrimination score for monosyllables was 0%. The speech discrimination scores of our patients were similar or higher than described for similar patient groups implanted with other devices. The high stimulation rate of the implant system using the continuous interleaved speech processing strategy as well as a deep atraumatic electrode insertion into the apicalmost regions of the scala tympani may be the reason for good performance.     

Cochlear implantation of children with minimal open-set speech recognition skills

OBJECTIVE: The purpose of this study was to evaluate the postoperative performance of 12 children who demonstrated some open-set speech recognition skills before receiving a Nucleus multichannel cochlear implant with a view toward expanding the selection criteria for cochlear implant candidacy to include children who derive minimal benefit from amplification. DESIGN: Pre- and postoperative performance of two groups of children were compared. Group 1 consisted of 12 children who demonstrated some open-set speech recognition skills before receiving a Nucleus multichannel cochlear implant (Borderline group). Group 2 consisted of 12 children who demonstrated no open-set speech recognition skills before implantation with a Nucleus device (Traditional group). In all children, candidacy was determined based on preimplant binaural aided performance. For most subjects, the poorer ear was selected for implantation. Mean pre- and postoperative speech recognition scores of the Borderline subjects were compared to determine the benefit provided by their cochlear implants. Secondly, matched-pair analyses were used to compare the mean speech recognition scores obtained by the Borderline and Traditional subjects. RESULTS: The scores of the Borderline group improved significantly on five of six speech recognition measures when 6 mo postoperative scores obtained with the implant were compared with preoperative test scores obtained with hearing aids. By the 12 mo postoperative interval, the scores of the Borderline group had improved significantly (p < 0.05) on all six measures. In contrast, scores obtained by the Traditional group had improved significantly on three of six measures at both the 6 and 12 mo postoperative intervals. Comparison of postoperative test scores revealed that the Borderline group scored significantly higher than the Traditional group on three of six measures at the 6 mo test interval and on six of six measures at the 12 mo test interval (p < 0.05). CONCLUSIONS: The findings of this study indicate that both groups derive significant benefit from their cochlear implants. Although the mean preoperative audiograms for the implanted ears did not differ significantly for the two groups of subjects, members of the Borderline group exhibited significantly better speech recognition skills than the Traditional group during the first year after implantation. These findings suggest that the increased auditory experience of the Borderline subjects positively influenced their performance with a cochlear implant. The authors advocate that the selection criteria used to determine pediatric cochlear implant candidacy be broadened to include consideration of children who demonstrate minimal open-set speech recognition skills.     

Long-term hearing results following vestibular surgery in Meniere's disease

OBJECTIVES: The purpose of this study is to evaluate the long-term hearing changes following vestibular surgery in patients with Meniere's disease. Study DESIGN: This is a retrospective analysis of patients operated on in a tertiary referral center setting. METHODS: Preoperative, postoperative, and 3- to 9-year postoperative audiograms were analyzed in two patient groups. Twenty-one patients underwent posterior fossa vestibular neurectomy (VN) and five, mastoid endolymphatic sac decompression and shunt (ELS). All frequencies, four-frequency pure-tone averages (PTAs), spondee thresholds, and speech recognition scores were compared for operated ear against nonoperated ear of VN subjects. The results were subjected to a covariance analysis. VN and ELS patients whose hearing deteriorated from "serviceable" (PTA < or =70 dB hearing level) and speech recognition > or =30%) to nonserviceable status were compared using nonparametric statistics. RESULTS: Progressive hearing loss beyond the rate of change of the normal contralateral ear was evident in all patients. Serviceable hearing dropped from 81% to 43% of patients an average of 4 years following VN. CONCLUSIONS: VN patients have significant hearing deterioration over time in the operated ear. This finding suggests that continued postoperative medical management is necessary for patients undergoing VN.     

Cochlear implants in children

Cochlear implants are no longer considered new or experimental technology. Difficulty in evaluating the degree of hearing loss and response to traditional forms of amplification in young children makes pediatric cochlear implant candidacy a complex issue. Cochlear implantation and, in particular, pediatric cochlear implantation, requires a team commitment with contributions from surgeons, audiologists, speech pathologists, psychologists, and special educators. Elements discussed include assessment and candidacy issues, surgical technique, elements of a cochlear implant team, outcome assessment, and potential complications. The decision to perform pediatric cochlear implantation should not be undertaken without serious consideration to the enormous commitment required in both financial and personnel terms.     

Cochlear implant performance after reimplantation: a multicenter study

OBJECTIVE: This study compares auditory performance between original and replacement cochlear implants. STUDY DESIGN AND SETTING: Data from 18 U.S. cochlear implant programs were obtained by retrospective chart review. Patients received and returned subjective questionnaires. PATIENTS: Twenty-eight adults with once-functioning Nucleus 22 cochlear implants that failed received replacement Nucleus 22 cochlear implants in the same ears. MAIN OUTCOME MEASURES: Objective measures included sentence (CID Everyday Sentences or Iowa Sentences) and monosyllabic word (NU-6 Words or CNC Words) speech discrimination scores. Patients also rated and compared performance using subjective scales. RESULTS: Thirty-seven percent of patients had significantly higher sentence or word scores with their replacement cochlear implants than with their original implants, 26% had no significant change, and 37% had significantly poorer scores. Subjectively, 57% of patients reported that the performance of their replacement device was better or the same and 43% reported that it was poorer. There was no correlation between performance with the replacement cochlear implant and cause of the original device failure, duration of original device use before failure, surgical complications with either implantation, changes in electrode insertion depths, or preoperative variables, such as age, etiology, or duration of deafness. CONCLUSIONS: Speech recognition ability with a replacement cochlear implant may significantly increase or decrease from that with the original implant. Experienced cochlear implant patients facing reimplantation must be counseled regarding the possibility of differences in sound quality and speech recognition performance with their replacement device.     

Acquired transplant tolerance

For many people with profound hearing loss conventional hearing aids give only little support in speechreading. This study aims at optimizing the presentation of speech signals in the severely reduced dynamic range of the profoundly hearing impaired by means of multichannel compression and multichannel amplification. The speech signal in each of six 1-octave channels (125-4000 Hz) was compressed instantaneously, using compression ratios of 1, 2, 3, or 5, and a compression threshold of 35 dB below peak level. A total of eight conditions were composed in which the compression ratio varied per channel. Sentences were presented audio-visually to 16 profoundly hearing-impaired subjects and syllable intelligibility was measured. Results show that all auditory signals are valuable supplements to speechreading. No clear overall preference is found for any of the compression conditions, but relatively high compression ratios (> 3-5) have a significantly detrimental effect. Inspection of the individual results reveals that compression may be beneficial for one subject.     

Treatment of intractable Menière's disease with intratympanic gentamicin: review of the University of Ottawa experience

OBJECTIVE: Intractable Meniere's disease has traditionally been treated surgically, with either labyrinthectomy, vestibular nerve section, or endolymphatic sac procedures. Another option is the use of intratympanic gentamicin to effect a 'gentamicin labyrinthectomy.' Nedzelski and coworkers have previously reported an 83% complete elimination and 17% substantial reduction in vertigo using this method. METHOD: We retrospectively reviewed 21 patients treated at our centre with intratympanic gentamicin between 1991 and 1995, all of whom fulfilled the criteria for reporting results in Meniere's therapy described in the American Association of Otolaryngology Committee on Hearing and Equilibrium 1995 guidelines. Our patients are presented using these guidelines, specifically examining four criteria: frequency of vertigo, word recognition, functional level, and hearing threshold. RESULTS: At 2-year follow-up, 17 of 21 patients (80.9%) had complete elimination of vertigo, with 3 of 21 (14.3%) reporting a 60 to 99% reduction in frequency. Nineteen of 21 patients (90.5%) described themselves as having no impairment secondary to dizziness. Average hearing thresholds and word-recognition scores appear to have both worsened after gentamicin therapy. CONCLUSION: Intratympanic gentamicin therapy for vertigo in Meniere's disease was shown to be an effective treatment choice, as shown by our results. However, with the reduction of average hearing thresholds and word-recognition scores, patients should be advised of these possible complications as part of informed consent.     

A review of 308 cases of revision stapedectomy

OBJECTIVE/HYPOTHESIS: Identify causes of primary and revision stapedectomy failure in 308 patients, assess whether these are different based on source of initial surgery, and evaluate hearing results in revision stapedectomy to improve outcome. Study Design: Retrospective, nonrandomized chart review of patients undergoing revision stapedectomy in a referral otology practice in a large metropolitan region. MATERIALS AND METHODS: Intraoperative findings, preoperative and postoperative revision stapedectomy air and bone conduction pure-tone averages, speech discrimination scores, postoperative air-bone gaps, complications, and repeated revisions were noted in 308 patients. RESULTS: Leading causes of primary stapedectomy failure included dislocated prosthesis (24.4%), inadequate prosthesis length (14%), long process resorption (14%), and fibrous adhesions (13.6%). Revision stapedectomy air-bone gaps were less than 10 dB in 80% and greater than 30 dB in 6.8% of cases. Increased sensorineural hearing loss occurred in 0.8% of revision stapedectomy cases. Five of seven cases of vertigo associated with primary stapedectomy resolved after revision surgery. CONCLUSION: Revision stapedectomy by experienced surgeons is highly effective in attaining successful air-bone gap closure in 80% and improved closure in 84.8% of operative cases. Risk of vertigo and/or sensorineural hearing loss was not any higher in this patient population when compared with reports of primary stapedectomy.     

Cochlear implants in children

Cochlear implants allow the rehabilitation of children with severe to profound hearing loss. They are beneficial for not only postlingual children with hearing loss but also for children with congenital or prelingual hearing loss. Issues regarding cochlear implant candidacy and surgery are discussed. The results of cochlear implants in children and the complications related to cochlear implant surgery in children are reviewed.     

Communication and noise. Speech intelligibility of airplane pilots with and without active noise compensation

Noise exposure measurements were performed with pilots of the German Federal Navy during flight situations. The ambient noise levels during regular flight were maintained at levels above a 90 dB A-weighted level. This noise intensity requires wearing ear protection to avoid sound-induced hearing loss. To be able to understand radio communication (ATC) in spite of a noisy environment, headphone volume must be raised above the noise of the engines. The use of ear plugs in addition to the headsets and flight helmets is only of limited value because personal ear protection affects the intelligibility of ATC. Whereas speech intelligibility of pilots with normal hearing is affected to only a smaller degree, pilots with pre-existing high-frequency hearing losses show substantial impairments of speech intelligibility that vary in proportion to the hearing deficit present. Communication abilities can be reduced drastically, which in turn can affect air traffic security. The development of active noise compensation devices (ANC) that make use of the "anti-noise" principle may be a solution to this dilemma. To evaluate the effectiveness of an ANC-system and its influence on speech intelligibility, speech audiometry was performed with a German standardized test during simulated flight conditions with helicopter pilots. Results demonstrate the helpful effect on speech understanding especially for pilots with noise-induced hearing losses. This may help to avoid pre-retirement professional disability.