Open-set Speech Understanding Research Articles

Neurofibromatosis type 2 and auditory brainstem implantation

Neurofibromatosis type 2 and auditory brainstem implantation

Cochlear implantation in the irradiated temporal bone

To demonstrate the feasibility and complexities of cochlear implantation in the setting of bilateral temporal bone osteoradionecrosis. Case report. Tertiary care referral centre. A 66-year-old woman with bilateral temporal bone osteoradionecrosis and profound hearing loss, following treatment for tonsillar cancer, underwent cochlear implantation. Prior canal wall down mastoidectomy and subsequent temporal bone resection with free flap reconstruction had been performed on the implanted ear. The contralateral ear received a canal wall down mastoidectomy. A completely dehiscent mastoid segment of the facial nerve and extensive fibrosis were evident in the implanted ear. Only minimal fibrous reaction was found within the cochlea, allowing for full electrode insertion. At three months, speech recognition testing documented a consonant-nucleus-consonant (CNC) word score of 54 per cent. This report demonstrates the feasibility of cochlear implantation after temporal bone surgery and free flap reconstruction in the setting of diffuse osteoradionecrosis. The patient's excellent open-set speech understanding using the cochlear implant implies that radiation did not severely damage the central auditory pathways. Thus, some patients with radiation-induced hearing loss may be appropriate cochlear implant candidates. Special attention should be paid to surgical planning, as complications related to wound healing, electrode insertion and facial nerve injury may be more likely.

Three-year follow-up of children with open-set speech recognition who use the MED-EL cochlear implant system

Improvement in implant technology and the fact that children with cochlear implants have surpassed all expectations have led the field to believe that open-set speech understanding is a common and expected outcome. The available literature suggests this to be the case in open-set word understanding. This study shows the results of 41 pre-lingually deafened children with a minimum of 3 years' cochlear implant experience assessed on the EARS test battery, which includes open-set phoneme, word and sentence tests. Results show that some open-set skills emerge by 6 months after implantation. There was significant improvement over time, even after 3 years of cochlear implant experience. A significant effect of age at implantation was also demonstrated. Results suggest that cochlear-implanted children develop open-set speech recognition soon after implantation, and these skills develop over a long period of time, highlighting the need for continued therapy to maximize listening and learning.

Three-year follow-up of children with open-set speech recognition who use the MED-EL cochlear implant system

Improvement in implant technology and the fact that children with cochlear implants have surpassed all expectations have led the field to believe that open-set speech understanding is a common and expected outcome. The available literature suggests this to be the case in open-set word understanding. This study shows the results of 41 pre-lingually deafened children with a minimum of 3 years' cochlear implant experience assessed on the EARS test battery, which includes open-set phoneme, word and sentence tests. Results show that some open-set skills emerge by 6 months after implantation. There was significant improvement over time, even after 3 years of cochlear implant experience. A significant effect of age at implantation was also demonstrated. Results suggest that cochlear-implanted children develop open-set speech recognition soon after implantation, and these skills develop over a long period of time, highlighting the need for continued therapy to maximize listening and learning.

Cochlear implants in children: safety as well as speech and language

The development of cochlear implants for children at the University of Melbourne and the Bionic Ear Institute, has consisted of a routine of biological and engineering safety followed by evaluation of speech processing strategies on adults before they are undertaken on children. The initial safety studies were to ensure that insertion was atraumatic, the electrical stimulus parameters did not lead to loss of ganglion cells and that the electrode could be inserted without the risk of middle ear infection leading to meningitis. The initial second formant extraction scheme was shown to produce significant open-set speech understanding in adults and was approved by the US Food and Drug Administration (FDA) in 1985. Following this, an international study was undertaken for the FDA on children using a strategy that also included the first formant, and was approved in 1990. Additional advances in speech processing have been evaluated on adults. However, before using one with high rates of stimulation, it was tested for safety on experimental animals. Further advances have been anticipated in particular through the development of a peri-modiolar array, the Nucleus Contour. Prior to its use on adults, it was tested in the human temporal bone and found to lead to minimal trauma. It was evaluated in adults and found to lead to better current localization and lower thresholds. A study was undertaken in children using a spectral maxima scheme at high rates (advanced combination encoder (ACE)) and the Contour array as it had given best results in adults. It was approved as safe and effective for use in children in 2000. Studies were also undertaken to look at plasticity and visual dominance particularly through cognitive studies and the use of the McGurk effect. This demonstrated that deaf children with implants rely heavily on visual information and there is a great need to have unambiguous auditory stimuli to get best results.

Cochlear implants in Children: safety as well as speech and language

The development of cochlear implants for children at the University of Melbourne/Bionic Ear Institute has consisted of a routine of biological and engineering safety followed by evaluation of speech processing strategies on adults before they are undertaken on children. The initial safety studies were to ensure that insertion was atraumatic, the electrical stimulus parameters did not lead to loss of ganglion cells and that the electrode could be inserted without the risk of middle ear infection leading to meningitis.The initial second formant extraction scheme was shown to produce significant open set speech understanding in adults and was approved by the U.S. Food and Drug Administration (FDA) in 1985. Following this, an international study was undertaken for the FDA on children using a strategy that also included the first formant, and was approved in 1990.Additional advances in speech processing have been evaluated on adults. However, before using one with high rates os stimulation it was tested for safety on experimental animals. Further advances have been anticipated in particular through the development of a perimodiolar array, the Nucleus “Contour.” Prior to its use on adults, it was tested in the human temporal bone and found to lead to minimal trauma. It was evaluated in adults and found to lead to better current localization and lower thresholds. A study was undertaken in children using a spectral maxima scheme at high rates (ACE) and the contour array as it had given best results in adults. It was approved as safe and effective for use in children in 2000.Studies have also been undertaken to look at plasticity and visual dominance particularly through cognitive studies and the use of the McGurk effect. This demonstrated that deaf children with implants rely heavily on visual information and there is a great need to have unambiguous auditory stimuli to get best results.

Cochlear implantation for adolescents and adults with prelinguistic deafness.

Previous studies have suggested that individuals with long-term prelinguistic deafness who receive cochlear implants show little improvement in speech recognition skills. The purpose of this study was to examine the auditory functioning of individuals with prelinguistic deafness who received cochlear implants after the age of 12. A retrospective study of open-set speech recognition was undertaken for 15 patients (adolescents and adults) with prelinguistic deafness who underwent implantation in the Ottawa Cochlear Implant Program. The results of open-set speech perception tests, both words and sentences, were reviewed to assess auditory functioning after implantation. Qualitative data using the Performance Inventory for Profound and Severe Loss questionnaire were also collected for the adults. The results of this study indicate that individuals with long-term prelinguistic deafness can achieve significant open-set speech understanding with a cochlear implant, although there is a wide range of performance across patients. The results ranged from 0% to 74% for words and 0% to 98% for sentences.

The history of cochlear implantation: from Volta to multichannel-intracochlear stimulation

Seit der Consensus Conference 1995 ist das Cochlear Implant (CI) als Methode der Wahl bei cochleäer Taubheit etabliert. Mit Hilfe des CI ist es erstmals möglich, den auditiven Sinneskanal nach dem Funktionsverlust des Perzeptionsorganes wieder zu nutzen. Weltweit tragen heute mehr als 30 000 Patienten ein CI. Mittlerweile erscheint es bereits selbstverständlich, die Therapie mit Innenohrimplantaten in das Spektrum der HNO-ärztlichen Behandlung als eine Standardtherapie einzubeziehen.

Delayed implantation in congenitally deaf children and adults.

To determine the efficacy of cochlear implants with current processing strategies in children and adults with long-term congenital deafness, and to determine whether the growth of auditory perceptual skills in these patients is similar to the data reported for patients who have undergone implantation with earlier devices and coding strategies. A prospective study of children and adults fulfilling the study inclusion criteria. University medical center. Thirty-five congenitally deaf children who received implants after the age of 8 years and 14 congenitally deaf adults who received implants as adults participated in this study. Length of device use ranged from 6 months to 3 years. Open set phoneme, word recognition tests, and sentence recognition tests were administered in quiet and noise auditory only conditions preoperatively and postoperatively. Changes in test scores were examined by paired t tests, and differences between groups were compared by Student's t tests. Spearman correlation coefficients were calculated to identify associations between scores and subject characteristics. A two-sided alpha of less than 0.05 was considered statistically significant. The results indicated significant improvement in open set speech perception skills in the children after implantation; the adults demonstrated improved mean scores on both word and sentence recognition. A shorter length of deafness correlated with better postoperative performance, but all subjects continued to improve over time. The improvement in test scores was similar between the devices, and no significant differences were detected between the different processing strategies. Children and adults with long-term congenital deafness can obtain considerable open set speech understanding after implantation. Length of deafness (age at implantation), length of device use, and mode of communication contribute to outcome.

Nucleus 21-Channel Auditory Brainstem Implant in Patients with Previous Tumour Removal: El implante auditivo de tallo cerebral Nucleus de 21 canales en pacientes con reseccion tumoral previa

Three patients with neurofibromatosis type 2 who had undergone previous cochlear nerve tumour removal were implanted with the Nucleus 21-channel auditory brainstem implant (ABI). The time intervals between tumour removal and implantation were 4, 5, and 7 years, respectively. Total bilateral deafness was confirmed before implantation. One patient was also blind after acute intracranial hypertension. The translabyrinthine approach was used in all cases. The choice of side for implantation depended on pre-operative magnetic resonance imaging study, the facial nerve function, the presence of recurrent and/or other lesions, and the patient's preference. Although the scarring of prior surgical procedure largely changed the anatomical structures in the cerebello-pontine angle, various landmarks could be found to locate the foramen of Luschka, where the ABI electrode was inserted into the lateral recess of the fourth ventricle. During surgery, the electrically evoked auditory brainstem responses were recorded to confirm that the ABI stimulation activated the auditory system; the electromyogram of the 7th and 9th nerves was helpful in finding the landmarks and minimising the triggering of the cranial nerves with ABI stimulation. The number of active electrodes was 21, 7, and 4 in the three patients. All obtained meaningful pitch scaling and useful auditory sensations. One patient, with 21 activated electrodes, has achieved functional open-set speech understanding. The second patient, with 7 activated electrodes, has benefited from environmental sound awareness and improved lipreading. The last, blind, patient, with 4 electrodes activated, achieved only perception of environmental sounds.

Early and long-term results of rehabilitation of cochlear implant patients]

Cochlear implantation is nowadays a reliable and well-accepted method of auditory rehabilitation in selected adults and children. We present rehabilitation data on 21 adult patients provided with the Nucleus CI22 M cochlear implant using the SPEAK strategy. Results of first tune-up show an open set speech understanding in approximately 50% of patients. Long-term results also reveal further improvement in patients who had no open set speech understanding. Our data seem to indicate similar results in comparison to other groups using the CIS strategy. In adults, open set speech understanding can be achieved even at the first tune-up. Results of early rehabilitation seem to be influenced by duration and etiology of deafness, experience with hearing aids, and other factors.

The Vienna Cochlear Implant Program

The cochlear implant program in Vienna has now gathered 160 patient years of experience with 25 patients who have received an extracochlear implant prosthesis and 31 patients who have received an intracochlear implant prosthesis. The sound processor avoids the transformation of speech into pulses and provides a processed analog broad-band stimulation signal. Approximately one half of the patients are prelingually deaf. The selection criteria include electrical promontory stimulation and acoustic and electrical brain-stem audiometry. The rehabilitation program consisting of counseling, communication training, and auditory training is considered an important part of the program. The results are assessed using the Vienna Auditory Test battery. Sixty per cent of the postlingually deafened patients achieve some open-set speech understanding without lip-reading. Sixty-five per cent of the users show a substantial improvement in aided speech understanding versus lip-reading alone.

Clinical Results Using a Multiple-channel Cochlear Prosthesis

A total of eight profoundly deaf patients have been implanted with the Nucleus Limited multiple-channel cochlear prosthesis at the University of Melbourne since it became available in late 1982. All patients are everyday users of the device. Speech testing using the device alone has shown consistently high scores for a variety of closed set tests and significant levels of open set speech understanding in most of the patients. Lipreading assessment with phoneme, word, sentence and speech tracking material shows significant improvement when using the prosthesis for all patients tested. Other benefits reported are recognition of environmental sounds, decrease in tinnitus, increased confidence in social and vocational situations and improved voice control. One patient is able to cope with interactive conversations over the telephone and three others are able to use the telephone in a limited way without special codes.