Choosing which ear to implant in adult candidates with functional residual hearing

This study examined whether audiologists consider the potential benefits of contralateral hearing aid use following cochlear implantation when recommending which ear to implant in UK adult candidates with residual hearing. Thirty-four audiologists from providers of adult implantation services completed a decision-choice experiment. Clinicians were willing to consider recommending that the poorer ear be implanted, provided it had been aided continuously, suggesting that their decision making seeks to preserve access to residual hearing in the non-implanted ear where possible. Future approaches to determining candidacy should therefore consider that a sub-set of patients may obtain additional benefit from this residual hearing following implantation.     

不同策略的声电双模式助听对事件相关电位的影响

目的 探讨听障儿童单侧耳植入人工耳蜗(cochlear implant,CI)后对侧耳联合使用助听器(hearing aid,HA)的双模式助听策略对事件相关电位P300的影响.方法 研究对象共52人,设实验组(人工耳蜗植入儿童)3组、听力正常对照组1组,每组13人,按实验设计步骤随机测试.按对侧耳配戴HA的不同将人工耳蜗植入儿童分为A(CI+模拟HA)、B(CI+数字HA,未优化)和C(CI+数字HA,优化)3组,评估实验对象术后左右耳的残余听力,分别设置和优化CI及HA的技术参数并在声场中评估其助听后的音频感知情况,测试并比较各组的P300潜伏期及振幅.结果 3组患者术后双耳均有残余听力,助听后组间比较无差别(P>0.05).P300潜伏期比较A组>B组>C组(P<0.05),A、B两组P300潜伏期比对照组延长(P<0.05),C组与对照组比较无差别(P>0.05);P300振幅A组和B组与对照组比较均无意义(P>0.05),C组P300振幅低于对照组(P<0.05).结论 大部分听障儿童一侧耳植入人工耳蜗后对侧耳仍有可利用的残余听力,可以联合配戴适合的全数字编程助听器,大脑听觉中枢可以整合声电双模式助听设备上传的听觉信息.     

Cochlear implantation in patients with substantial residual hearing

OBJECTIVES: Cochlear implantation is an effective means for providing auditory rehabilitation in adult patients with severe to profound sensorineural hearing loss. It has been hypothesized that patients with substantial, preoperative residual hearing would be excellent cochlear implant candidates because of surviving neural populations and a lack of auditory deprivation. The purpose of this study is to describe the outcomes of patients with substantial residual hearing who have undergone cochlear implantation. STUDY DESIGN: Retrospective chart review of patients with substantial preoperative residual hearing who underwent cochlear implantation. METHODS: Chart reviews were completed for patients with substantial residual hearing who underwent cochlear implantation (City University of New York Sentence Test [CUNY] > 60%, Hearing in Noise Test sentences presented in quiet [HINTQ] > 50%, or Consonant-Nucleus-Consonant [CNC] > 20% in the ear to be implanted). Preoperative and postoperative measures of audiologic performance as well as complications were assessed. RESULTS: All 12 patients who met inclusion criteria ultimately surpassed their preoperative aided performance level after implantation and gained significant benefit from their cochlear implant. At 6 months postimplantation, mean CUNY, HINTQ, and CNC scores were 93%, 78%, and 48% in the implant ear alone, respectively. However, progress was slower than expected for many patients, and at least one patient took 1 year to surpass his preoperative performance level. There were no complications from surgery in this selected group of patients. CONCLUSIONS: Patients with some degree of residual hearing do benefit from cochlear implantation. However, there may be an initial decline in performance as compared with preoperative levels. This decline is overcome in time in this patient population. These patients need to be counseled accordingly.     

双耳双模式聆听的优势及目前存在的问题

近十年来,人工耳蜗植入已经成为治疗小儿和成人重度以上感音性神经性聋的标准疗法.但在耳聋患者中存在这样一群特殊患者,他们一侧耳重度或极重度聋,但对侧耳尚有一定的残余听力.在中国大多数此类患者接受了单侧人工耳蜗植入,形成了单耳听觉.然而对于这些患者,其单侧人工耳蜗植入在其音调、音乐感知以及声源定位等能力并没有达到理想状态,是以针对那些对侧耳有残余听力的单侧人工耳蜗植入者,出现了给非植入耳佩带助听器的“双耳双模装配”模式,从而使患者能够“双耳双模式聆听”.那么相对于单耳听觉或双耳耳蜗模式究竟有何优势,并且就目前的研究或是技术而言,还存在哪些主要的问题呢？本文在回顾近年文献的基础上,对这些问题做一综述.     

Bimodal studies using adaptive dynamic range optimization (ADRO) technology

This study investigated the effects of adaptive dynamic range optimization (ADRO®) processing for six bimodal listeners who used a hearing aid in one ear and a cochlear implant in the other. ‘Bimodal’ refers to the use of acoustic and electrical stimulation together. Bimodal speech recognition thresholds with the Japanese hearing in noise test were significantly lower for two ADRO devices than two non-ADRO devices in quiet, in noise from the front, and in noise from the implanted side. When the noise was presented from the non-implanted side there was no significant difference between the ADRO and non-ADRO conditions. The hearing aid measure of contrast questionnaire indicated that participants preferred ADRO in 77.3% of situations. ADRO was especially preferred in more difficult situations. The ADRO processing was designed for use in bimodal prostheses, and this study confirmed that speech intelligibility and sound quality improvements are obtainable by using ADRO in a bimodal context.     

Comparison of two frequency-to-electrode maps for acoustic-electric stimulation

The fitting of a cochlear implant together with aided residual hearing was evaluated by means of matching frequency and/or perceived pitch between acoustic and electric modalities. Five cochlear implant users with the Nucleus^® Freedom? electrode array with residual acoustic hearing participated. Psychophysical procedures were used to create a map in which the implant was programmed to provide the listener with high-frequency information only above the frequency at which acoustic hearing was no longer considered useful. This was compared to a second map which provided the full frequency range. Listeners wore each map for a number of weeks before speech recognition was measured in quiet and noise. Post-operatively across subjects, average hearing thresholds worsened by 27 dB. However, cochlear implantation provided superior recognition of speech compared to pre-operative scores, with the best results found when subjects were wearing their hearing aids together with the implant. No significant differences were found between the two maps on speech tests when subjects were wearing their implant together with hearing aid/s. In conclusion, the combination of a cochlear implant together with hearing aid/s was effective at providing speech perception benefits for the listeners of the current study, regardless of the frequency-to-electrode allocation selected.     

Long-term results of hearing preservation cochlear implant surgery in patients with residual low frequency hearing

Conclusion: Differences were found between patients with stable hearing and those with progressive hearing loss in the lower frequencies with respect to the rate of progression in the contralateral ear. It is suggested that the electric acoustic stimulation (EAS) can provide improvement in hearing ability over the long-term if residual hearing might be lost to some extent.

Objective: To evaluate the long-term threshold changes in the low frequency hearing of the implanted ear as compared with the non-implanted ear, and the hearing abilities with EAS along with the extent of residual hearing.

Methods: Seventeen individuals were enrolled and received the EAS implant with a 24-mm FLEXeas electrode array. Hearing thresholds and speech perception were measured pre- and post-operatively for 1–5 years. Post-operative hearing preservation (HP) rates were calculated using the preservation numerical scale.

Results: The average linear regression coefficient for the decline in hearing preservation score was ?6.9 for the implanted ear and the patients were subsequently categorized into two groups: those with better than average, stable hearing; and those with worse than average, progressive hearing loss. EAS showed better results than electric stimulation alone, in spite of an absence of speech perception with acoustic stimulation.     

Unilateral cochlear implantation in children with a potentially useable contralateral ear

Increasingly, children are considered for a unilateral CI, even if the contralateral ear falls outside current audiological guidelines, especially if they are not considered to be reaching their educational potential. The primary aim was to investigate the benefit of unilateral CI in children currently outside UK [National Institute for Health and Care Excellence Technology Appraisal Guidance. 2009. Cochlear implants for children and adults with severe to profound deafness. NICE technology appraisal guidance [TAG166]. Available January 29, 2016 from http://www.nice.org.uk/ta166] audiological guidelines in the contralateral ear. The secondary aim was to measure compliance. A retrospective case review with standard demographic data was performed. Forty-seven children were identified as having received a unilateral CI with the contralateral ear falling outside of current UK audiological criteria. These children were allocated to two groups; with hearing between 50 and 70?dB, and 70 and 90?dB at 2 and 4?kHz in the contralateral ear, respectively. Categories of auditory performance (CAP) were assessed. Pre- and post-operative CAP scores demonstrated a statistically significant improvement in auditory perception. We would suggest that assessing candidacy in individual ears and subsequent unilateral CI, has given these children a benefit they may not otherwise have acquired if they only had bilateral hearing aid.     

有低频残余听力感音神经聋的人工耳蜗植入术

目的介绍一种有低频残余听力感音神经聋的人工耳蜗植入技术,探讨人工耳蜗植入手术对有残余听力患者的治疗效果和价值。方法15例有残余听力的患者接受了保护残余听力的人工耳蜗植入手术。术中电极植入深度在19mm～24mm左右。术后分别检测单纯使用助听器、单纯使用人工耳蜗、人工耳蜗结合助听器三种不同状态下的听力。结果15例患者中,有13例术后残余听力保存良好,仅分别丢失5～20dB听力,但另2例术后残余听力全部丧失。术后在安静、信噪比15dB和10dB三种不同状态下的言语测试结果显示,人工耳蜗结合助听器使用者测试得分始终保持在很高水平;单纯使用人工耳蜗者也有较好的成绩,但在信噪比达10dB的条件下,测试成绩下降;而单纯使用助听器者,不仅在安静状态下听力成绩不甚理想,一旦加入竞争性噪声,听力测试成绩急剧下降。结论保护和利用残余听力的人工耳蜗植入技术,使人工耳蜗植入手术对象从重度或极重度聋扩大到高频为重度或极重度聋,低频（≤500Hz）为中、轻度聋的患者。接受这项技术患者的听力和言语识别能力均明显优于其单纯配戴助听器和单纯使用人工耳蜗时的听力和言语识别能力。     

Residual hearing in cochlear implant patients

Preservation of residual hearing should be a desirable outcome of implant surgery. Prevention of neural degeneration due to loss of residual hair cells, together with the continuous progress in cochlear implant technology should be able to preserve cochlear integrity as well as possible. The degree of hearing preservation may vary depending on surgical approach, maximum insertion depth and other factors not uniformly considered to date. The aim of this retrospective case controlled study is to evaluate residual hearing after cochlear implant surgery. In particular, we analyzed data obtained with use of two different kinds of electrode arrays, with and without rigid introductor (stylet). We report the results on 37 patients with measurable preoperative hearing thresholds, mean age of 28 years (5–70 years), having the following implants: seven Advanced Bionics^®, four Med-El^®, 24 Cochlear^®, two MXM^®; 19 of them were performed using the stylet and the other 18 without it. A minimally invasive surgical approach was performed with a short retroauricular incision and a 1.2 mm cochleostomy. A complete electrode array insertion was obtained in all patients. Responses to pure-tone stimuli were measured for each ear in pre-implantation conditions and 3–12 months after surgery. After implantation 14 patients (38%) showed no hearing threshold variation, 29 (78%) maintained an appreciable hearing threshold level in the implanted ear, 8 (22%) had a total loss of residual hearing. Median increases of threshold levels were, in all 37 studied patients, 5, 10, 10 and 5 dB HL, respectively, for 125, 250, 500 and 1 kHz. For the 18 patients having implants without the stylet median increases of threshold levels were 0, 10, 5 and 7 dB HL; in the stylet group, they were 10, 5, 5 and 10 dB HL. On a comparison between the stylet and the non-stylet group, no significant differences in mean hearing threshold worsening were found. Data seem to suggest that cochlear function is less sensitive to mechanical trauma during implant surgery than was thought. Besides, electrode array stiffness seems not to influence preservation of cochlear residual functional integrity. Finally, the authors hypothesize a direct spiral ganglion activation under strong mechanical stimulation.     

Effect of preoperative residual hearing on speech perception after cochlear implantation

Objective: To assess the effect of substantial preoperative residual hearing on speech perception outcomes in adult cochlear implant recipients. Setting: Tertiary care academic referral center. Methods: Twenty‐nine patients with substantial preoperative residual hearing underwent cochlear implantation. Twenty‐one implant recipients matched for age and duration of hearing loss, but without preoperative residual hearing, served as controls. Postoperative speech perception was assessed using City University of New York sentence, consonant‐nucleus‐consonant, and hearing in noise test in quiet and in noise (+10 dB signal to noise ratio) tests at 1, 3, 6, and 12 months after fitting. Results: After implantation, there were no significant differences between groups for any of the tests administered. The mean change in speech perception abilities from baseline was significantly greater for the control patients than those with substantial preoperative residual hearing at a number of the test intervals across the various conditions. Moreover, at both 1 and 3 months, some patients in the residual hearing group had speech perception scores that were worse than their preoperative values. Ultimately, all of the patients with substantial residual hearing surpassed their preoperative performance. Discussion: Patients with substantial preoperative residual hearing can gain significant benefit from cochlear implantation. Although the degree of improvement in these individuals is somewhat more modest than for those patients without preoperative residual hearing, the outcomes are still excellent. That there were no significant differences between the patient groups suggests that having substantial residual hearing before implantation does not provide a measurable performance advantage for electrical stimulation. Patients with substantial residual hearing who are contemplating cochlear implantation should be counseled regarding a possible initial decline in speech perception performance.     

The hearing benefit of cochlear implantation for individuals with unilateral hearing loss,but no tinnitus

Conclusion: Cochlear implants improve the hearing abilities of individuals with unilateral hearing loss and no tinnitus. The benefit is no different from that seen in patients with unilateral hearing loss and incapacitating tinnitus.

Objective: To evaluate hearing outcomes after cochlear implantation in individuals with unilateral hearing loss and no tinnitus and compare them to those obtained in a similar group who had incapacitating tinnitus.

Methods: Six cases who did not experience tinnitus before operation and 15 subjects with pre-operative tinnitus were evaluated with a structured interview, a monosyllabic word test under difficult listening situations, a sound localization test, and an APHAB (abbreviated profile of hearing aid benefit) questionnaire.

Results: All subjects used their cochlear implant more than 8?hours a day, 7 days a week. In ‘no tinnitus’ patients, mean benefit of cochlear implantation was 19% for quiet speech, 15% for speech in noise (with the same signal-to-noise ratio in the implanted and non-implanted ear), and 16% for a more favourable signal-to-noise ratio at the implanted ear. Sound localization error improved by an average of 19°. The global score of APHAB improved by 16%. The benefits across all evaluations did not differ significantly between the ‘no tinnitus’ and ‘tinnitus’ groups.     

Does acoustic fundamental frequency information enhance cochlear implant performance?

Abstract

Objectives

Low-frequency information via an acoustic aid has been shown to increase speech intelligibility in noise for cochlear implant (CI) listeners. It has been suggested that fundamental frequency (F0) provides this advantage. This study aimed to investigate the contribution of F0.

Methods

Seven cochlear implant users having residual hearing at 125, 250, and 500 Hz contralateral to the implant were recruited. Speech intelligibility in noise was measured using an adaptive procedure for three listening conditions: (1) CI alone, (2) CI plus filtered acoustic information contralaterally, and (3) CI plus acoustic F0 contralaterally. In condition 2, the sentence material was low-passed at 500 Hz and presented via an insert earphone into the contralateral ear. In condition 3, F0 was extracted using Praat and presented as a sine wave with the same F0 variation over time as the original sentence.

Results

Although benefit was observed when low-frequency information was added for the majority of participants, on average no statistically significant difference was found for the three listening conditions.

Discussion

These results are not consistent with current literature. It is proposed that glimpsing cues may be responsible for the advantage observed in previous studies; in this study, both target and masker were presented in the acoustic condition and this may explain the discrepancy.

Conclusion

The benefit of additional acoustic information may be highly variable and individual to participants, but on average no statistically significant difference was seen.     

Effect of bimodal hearing in Korean children with profound hearing loss

Conclusion. Bimodal hearing with combined acoustic stimulation and electric stimulation could enhance speech performance in deaf patients by residual hearing even though the amount of residual hearing is not enough to be used for communication by amplification. Objectives. The cochlear implant (CI) is a well-known therapeutic option for patients with profound hearing loss. However, deaf patients with a CI still have trouble in localization of sounds and understanding speech in a noisy environment. The aim of this study was to evaluate the benefits of bimodal hearing with a CI in one ear and a hearing aid in the contralateral ear in Korean children with profound hearing loss. Subjects and methods. Fourteen deaf children with residual hearing participated in this study. There were eight male and six female patients, with an age range of 4.6–13.8 years at the time of testing. The test was conducted between 3 months and 4.2 years after cochlear implantation. Speech performance was examined in a noisy environment using Korean word lists. A speech sound and the noise were presented to the child from the front loudspeaker. Results. The results showed that speech performance in a noisy environment was significantly better with bimodal hearing than with a CI alone.     

Evidence-based guidelines for recommending cochlear implantation for postlingually deafened adults

Abstract

Objective: Adult selection criteria for cochlear implantation have been developed based on analysis of the post-operative performance of a large group of postlingually deafened adults. Original criteria published in 2004 were reviewed and amended to reflect outcomes currently being achieved by implant recipients. Design: Retrospective review of 12-month post-operative speech perception performance of adults implanted at the Eye and Ear Hospital, Melbourne, Australia. Study sample: A total of 382 postlingually deafened adults, using a Freedom, Nucleus 5, or CI422 Slim Straight cochlear implant were used to create a comparative set of data. Results: Revised guidelines suggest that adults with postlingual hearing loss can now be considered cochlear implant candidates if they obtain scores of up to 55% for open-set phonemes in quiet in the ear to be implanted. Functional benefit may vary depending on the recipients’ contralateral hearing. Conclusions: This study supports the provision of cochlear implants to candidates with significant residual hearing when at least one ear meets the criterion outlined above. Patient-specific counseling is required to ensure the potential to benefit predicted by the current model is acceptable to the individual patient and their family. Counseling regarding functional benefit must take into consideration hearing in the contralateral ear.     

语前聋患儿一侧人工耳蜗对侧助听器效果分析

目的:通过对人工耳蜗植入对侧耳不同听力损失的患儿联合使用助听器与人工耳蜗语前聋患儿的听觉、语言及学习能力进行评估和比较,探索对患儿更为有效的助听方法,帮助患儿获得最大限度的言语交流。方法:将30例3～6岁语前聋患儿按照植入人工耳蜗对侧耳听力损失程度及是否佩戴助听器,分为一侧人工耳蜗+对侧重度听力损失助听器组(CI+SHA组)、一侧人工耳蜗+对侧极重度听力损失助听器组(CI+PHA组)、单耳人工耳蜗组(CI组)。评估各组在康复3、6、9、12、15、18个月时听觉、语言及学习能力,并记录结果。结果:随着术后康复时间的延长,聋儿听觉、语言及学习能力逐渐提高(P<0.05),CI+SHA组听觉能力优于CI+PHA组及CI组(均P<0.05),语言能力及学习能力无明显差异(P>0.05)。结论:语前聋患儿单耳人工耳蜗植入后,若对侧耳尚有残余听力,佩戴助听器后听觉能力效果显著,长期佩戴有助于患儿的康复。     

A new electrode for residual hearing preservation in cochlear implantation: first clinical results

Conclusion. A so far unattained high rate (100%) of residual hearing preservation in cochlear implantation for electric-acoustic stimulation could be achieved using sophisticated surgical techniques in combination with the MedEl Flex EAS electrode. Objectives. This study aimed to gather first audiological and surgical results from the experience gained with the new MedEl Flex EAS electrode array. Patients and methods. Nine patients (aged 7.62–71.32 years) with profound high frequency hearing loss were supplied with this atraumatic electrode, which was designed to preserve residual hearing despite intracochlear insertion of an electrode array. All patients were implanted by the same surgeon. Results. Hearing preservation was achieved in all patients (complete preservation 44.44%) after a mean follow-up period of 9.73 months. Mean monosyllabic test scores improved from 9% correct with the hearing aid alone to 48% with the cochlear implant and to 65% in the electric-acoustic mode.     

Speech and language outcomes in children with auditory neuropathy/dys-synchrony managed with either cochlear implants or hearing aids

The aim of this study was to assess the receptive language and speech production abilities of a group of school-aged children with auditory neuropathy/dys-synchrony-type hearing loss. Ten children who had received a cochlear implant in one or both ears participated. Findings for this group were compared with those for a matched cohort of implanted children with other forms of sensorineural hearing loss and with those for a group of auditory neuropathy/dys-synchrony children who were long-term hearing aid users.

Results for 9 of the ten implanted children with auditory neuropathy/dys-synchrony were similar to those of the general population of paediatric implant recipients. (One child, who gained little perceptual benefit from his device, showed severely delayed spoken language development). Results for the group of aided auditory neuropathy/dys-synchrony subjects were comparable to those for their implanted counterparts suggesting that affected children should not automatically be considered cochlear implant candidates.     

Cochlear implant candidacy in the United States: prevalence in children 12 months to 6 years of age

OBJECTIVE: Pediatric cochlear implantation has been demonstrated to be effective for children as well as cost effective for society. One of Healthy People 2010 goals is to increase the number of people who are deaf or significantly hard of hearing to begin to use a cochlear implant system. NIDCDs Healthy Hearing Progress Reports from 1999 reported that only 2 out of every 1000 adults who are deaf or hard of hearing received a cochlear implant. There were two main objectives for this study: (1) to estimate the number of children between the ages of 12 months and 6 years of age with severe to profound bilateral hearing loss who could benefit from a cochlear implant and (2) to determine if the number of children projected to be candidates received this medical care. METHODS: Using the 2000 US Census Data from children 12 months to 6 years, the number of children with severe to profound bilateral hearing loss was calculated. Children who would be considered "neurologically devastated" and the children with absent eighth nerves were excluded from the calculations. RESULTS: Based on the total population of slightly over 231 million, 15,219 children presented with severe to profound hearing loss. Taking into account some exclusions, 12,816 children would be considered cochlear implant candidates. Based on the number of children who were implanted in 2000, approximately 55% of the projected number of candidates received a cochlear implant. CONCLUSION: Even though the estimates do not reflect a direct measure of actual candidates in the targeted age groups, the population who could benefit from this technology is still being significantly underserved in the United States. With a continued shortage of qualified personnel to serve these children, insufficient reimbursement rates, and disparities in implantation rates based on ethnicity and socioeconomic status, the question remains can we truly meet the needs of these children?     

Effects of loss of residual hearing on speech performance with the CI422 and the Hybrid-L electrode

Abstract

Objective

Preservation of residual low-frequency hearing has become a priority in cochlear implantation. The purpose of this study was to compare rates of hearing preservation and effects on performance of loss of low-frequency acoustic hearing with two different length electrodes.

Study design

Retrospective chart review.

Setting

Tertiary Care Hospital.

Patients

Twelve patients were implanted with the CI422 a slim-straight electrode; the second group consisted of 10 patients implanted with the Hybrid-L, a shorter hearing preservation electrode.

Main outcome measure

Audiometric thresholds and speech perception measures.

Results

At 1 year, 3/10 (30%) patients with the Hybrid-L and 7/12 (58%) patients with the CI422 lost residual acoustic hearing resulting in a profound hearing loss in the implanted ear. In comparing these patients in particular, mean CNC words in the implanted ear were 72% in the CI422 electrode group and 15% in the Hybrid-L electrode group at 1 year (P = 0.03). While hearing preservation rates with the Hybrid-L tended to be better, among recipients who lost residual hearing, speech perception was better in those with the longer CI422 electrode.

Conclusions

With emphasis on preservation of residual hearing, patients need to be counseled regarding possible outcomes and options should loss of residual hearing occur following implantation. While shorter electrodes may have better rates of hearing preservation, the patients with the longer straight electrode in our study had significantly better speech understanding following the loss of residual hearing.