Effects of residual speech and auditory deprivation on speech perception of adult cochlear implant recipients

Objective

Possible predictive factors of cochlear implant (CI) outcomes have been extensively reported in literature for different user groups such as prelingual pediatric or postlingual adult users. However, there remains unexplained outcome variability among adult CI users; therefore, research concerning these patients continues and many different variables have been reported. This study aimed at evaluating the relationship between preoperative speech reception capacity, residual hearing, duration of deafness, age of implantation, and postoperative monosyllabic word recognition scores (WRSs) in postlingual CI users.

Audiovisual speech perception in elderly cochlear implant recipients

OBJECTIVES/HYPOTHESIS: This study examined the speech perception skills of a younger and older group of cochlear implant recipients to determine the benefit that auditory and visual information provides for speech understanding. STUDY DESIGN: Retrospective review. METHODS: Pre- and postimplantation speech perception scores from the Consonant-Nucleus-Consonant (CNC), the Hearing In Noise sentence Test (HINT), and the City University of New York (CUNY) tests were analyzed for 34 postlingually deafened adult cochlear implant recipients. Half were elderly (i.e., >65 y old) and other half were middle aged (i.e., 39-53 y old). The CNC and HINT tests were administered using auditory-only presentation; the CUNY test was administered using auditory-only, vision-only, and audiovisual presentation conditions RESULTS: No differences were observed between the two age groups on the CNC and HINT tests. For a subset of individuals tested with the CUNY sentences, we found that the preimplantation speechreading scores of the younger group correlated negatively with auditory-only postimplant performance. Additionally, older individuals demonstrated a greater reliance on the integration of auditory and visual information to understand sentences than did the younger group CONCLUSIONS: On average, the auditory-only speech perception performance of older cochlear implant recipients was similar to the performance of younger adults. However, variability in speech perception abilities was observed within and between both age groups. Differences in speechreading skills between the younger and older individuals suggest that visual speech information is processed in a different manner for elderly individuals than it is for younger adult cochlear implant recipients.     

Optimizing the perception of soft speech and speech in noise with the Advanced Bionics cochlear implant system

Abstract

Objective: This study aimed to provide guidelines to optimize perception of soft speech and speech in noise for Advanced Bionics cochlear implant (CI) users. Design: Three programs differing in T-levels were created for ten subjects. Using the T-level setting that provided the lowest FM-tone, sound-field threshold levels for each subject, three additional programs were created with input dynamic range (IDR) settings of 50, 65 and 80 dB. Study sample: Subjects were postlinguistically deaf adults implanted with either the Clarion CII or 90K CI devices. Results: Sound-field threshold levels were lowest with T-levels set higher than 10% of M-levels and with the two widest IDRs. Group data revealed significantly higher scores for CNC words presented at a soft level with an IDR of 80 dB and 65 dB compared to 50 dB. Although no significant group differences were seen between the three IDRs for sentences in noise, significant individual differences were present. Conclusions: Setting Ts higher than the manufacturer's recommendation of 10% of M-levels and providing IDR options can improve overall speech perception; however, for some users, higher Ts and wider IDRs may not be appropriate. Based on the results of the study, clinical programming recommendations are provided.

Sumario

Objetivo: Este estudio buscó proporcionar pautas para optimizar la percepción del lenguaje suave y del lenguaje en ruido para usuarios del implante coclear (IC) de Advanced Bionics. Diseño: Se crearon tres programas para diez pacientes, que eran diferentes en sus niveles T. Al usar el control de nivel T que proporcionaba el tono FM más bajo, con niveles de umbral en campo libre para cada sujeto, se crearon tres programas adicionales con controles de ingreso del rango dinámico IRD de 50, 65 y 80 dB. Muestra de Estudio: Los sujetos fueron sordos adultos postlingüísticos implantados con los modelos Clarion CII o 90K CI. Resultados: Los niveles de umbral en campo libre fueron más bajos con los niveles T colocados 10% más alto que los niveles M y con los dos IDR más anchos. Los datos del grupo revelaron puntuaciones significativamente mayores con palabras CNC presentadas en un nivel suave con un IDR de 80 dB y 65 dB comparados con 50 dB. No obstante que no se encontraron diferencias significativas en los grupos entre los tres IDR para oraciones en ruido, si se presentaron diferencias significativas individuales. Conclusiones: La colocación de los niveles T más altos en 10% que la recomendación del fabricante, sobre los niveles M y el proporcionar opciones de IDR, en general pueden mejorar la percepción del lenguaje; no obstante, niveles mayores de T y IDR más anchas, pueden no ser apropiados para algunos usuarios. Con base en los resultados de este estudio, se proporcionan recomendaciones clínicas para la programación.     

Electrical stimulation rate effects on speech perception in cochlear implants

The objective of this study was to explore cochlear implant users’ speech perception performance in quiet and in noise for low to moderate stimulation rates. Eight postlingually deaf adult users of the Nucleus CI24 cochlear implant (contour electrode array) using the ESPrit 3G speech processor participated in this study. Monosyllabic word recognition in quiet and sentence perception in noise was evaluated for low to moderate stimulation rates of 275, 350, 500, and 900 pulses-per-second/channel (pps/ch). All four stimulation rate programs were balanced for loudness. A repeated ABCD experimental design was employed. Take home practice was provided with each stimulation rate. Subjects also responded to a comparative questionnaire to examine their rate preference for a variety of listening situations. Results for six of the eight subjects showed no significant effect of rate for monosyllables in quiet. However, results for the sentence test in noise demonstrated improvements with 500 or 900 pps/ch stimulation rates in seven out of the eight subjects. Although there was not a close relationship between each subject's subjective preference and the rate program that provided best speech perception, most subjects indicated a preference for 500 pps/ch rate in noise.     

Perception of speech by prelingual pre-adolescent and adolescent cochlear implant users

Abstract

This study was undertaken to assess the speech perception benefits, 24 months after cochlear implantation (CI), in 20 young people (age at CI, 8–18.5 years) with prelingual profound hearing loss, in addition to the use of a proposed CI candidacy assessment profile. Speech perception was evaluated in terms of word and sentence perception before CI, and at six-monthly intervals for two years after CI. Before undergoing CI, all participants were tested on a pre-implantation assessment profile. Compared to the pre-CI findings, group results over 24 months post-CI demonstrated improved speech perception abilities reaching, on average, 46% for word recognition, 71.3% for sentences in quiet, and 33.6% for sentences in noise. Pre-CI profile scores correlated significantly with all speech perception results obtained 24 months after CI. Thus, despite their relatively late ages at implantation, all participants showed gradually improving performance in speech perception. The results showed a high variability in the outcomes of the participants. The pre-CI profile appeared to be useful in formulating realistic expectations of CI outcome during pre-implantation consultations, suggesting that expectations can and should be managed according to each patient's pre-implantation assessment.

Sumario

Se llevó a cabo este estudio para evaluar los beneficios en la percepción del lenguaje, 24 meses después de la implant-ación coclear (CI), en 20 personas jóvenes (edad en la CI de 8-18.5 años), con sordera prelingüística profunda, en quienes se usó un perfil propuesto de evaluación para la candidatura a la CI. La percepción del lenguaje se evaluó en términos de percepción de palabras y oraciones antes de la CI y a intervalos de seis meses, durante dos años, después de la CI. Antes de la CI todos los participantes fueron examinados con un perfil de evaluación pre-implantación. Comparados con los hallazgos pre-CI, los resultados del grupo después de 24 meses de la CI mostraron mejoría en las habilidades para la percepción del lenguaje alcanzando, en promedio, 46% para el reconocimiento de palabras, 71.3% para oraciones sin ruido y 33.6% para oraciones con ruido. Las puntuaciones en el perfil pre-CI correlacionaron significativamente con todos los resultados de percepción del lenguaje obtenidos 24 meses después de la CI. Así, a pesar de las edades de implantación relativamente tardías, todos los participantes mostraron un desempeño gradual-mente mejor en la percepción del lenguaje. Los resultados mostraron una gran variabilidad en los resultados de los participantes. El Perfil pre-CI parece ser útil para formular expectativas realistas sobre los resultados de la CI durante las consultas pre-implante, sugiriendo que las expectativas pueden y deben ser manejadas de acuerdo con las evaluaciones pre-implantación de cada paciente.     

双侧人工耳蜗植入术后言语识别效果的评估

目的评估双侧人工耳蜗植入者汉语普通话短句、双音节词单音节词及汉语声调的识别效果,探索双侧人工耳蜗植入者双耳听觉产生的机制及对言语识别率的影响。方法选取双侧人工耳蜗植入患者6人,自制问卷收集受试者的基本信息并评估他们的主观听觉状况。首先测试受试者在使用双侧人工耳蜗（BCI）、单独使用一侧人工耳蜗（RCI/LCI）的听阈,随后测试他们在BCI和RCI/LCI两种听觉模式下的七音节短句、双音节词、声调、韵母、声母识别率,测试背景环境包括安静环境和嘈杂语噪声环境,言语信号强度为65dB SPL,固定信噪比为+10 dB SPL。随后将BCI和RCI/LCI两种听觉模式下的识别效果进行比较。结果除噪声状态下韵母识别测试中其余测试结果均为BCI言语识别率得分高于RCI/LCI。结论对于符合双侧人工耳蜗植入术适应证标准的患者而言,双侧植入人工耳蜗可以在不同程度上提高安静和噪声环境下的短句、双字词、声母、韵母及声调的识别率,降低其声场听阈。     

The long-term results of speech perception in elderly cochlear implant users

Objectives: To evaluate the speech discrimination performance of elderly post-lingually deafened cochlear implant (CI) users and the stability of performance over time relative to a control group of younger CI users.

Methods: The study group consisted of 20 native Dutch speaking, post-lingually deafened CI users, aged 70 or older at the time of implantation. Controls were patients aged 40–60 years at implantation and included according to the same inclusion criteria (except age). Linear mixed models assessed speech recognition scores between groups, the variability of their performance, and stability over time.

Results: 20 elderly and 37 controls were included. The mean follow-up was 4.4 and 5.3 years for elderly and controls, respectively. There was no significant difference in average speech discrimination between both groups. The elderly group had a larger intra-subject variability over time. There was no significant effect of follow-up on the speech discrimination, indicating a stable performance over time.

Discussion: This study has a longer follow-up than methodologically comparable previous studies. We found no difference in speech discrimination between elderly patients and controls and no deterioration of performance over time. The subjects in the elderly group exhibit a larger variability around their mean performance.

Conclusion: Speech recognition in both elderly and younger adult CI users is stable over time and is not significantly related to the age of implantation.     

The effect of pre-operative developmental delays on the speech perception of children with cochlear implants

Objective

The objective of this study was to evaluate the relationship between developmental delays and speech perception in pre-lingually deafened cochlear implant recipients.

Methods

This study was a retrospective review of patient charts conducted at a tertiary referral center. Thirty-five pre-lingually deafened children underwent multichannel cochlear implantation and habilitation at the Kyoto University Hospital Department of Otolaryngology-Head and Neck Surgery. A pre-operative cognitive–adaptive developmental quotient was evaluated using the Kyoto scale of psychological development. Post-operative speech performance was evaluated with speech perception tests two years after cochlear implantation. We computed partial correlation coefficients (controlled for age at the time of implantation and the average pre-operative aided hearing level) between the cognitive–adaptive developmental quotient and speech performance.

Results

A developmental delay in the cognitive–adaptive area was weakly correlated with speech perception (partial correlation coefficients for consonant–vowel syllables and phrases were 0.38 and 0.36, respectively).

Conclusion

A pre-operative developmental delay was only weakly associated with poor post-operative speech perception in pre-lingually deafened cochlear implant recipients.     

Speech and music perception with the new fine structure speech coding strategy: preliminary results

Conclusions. Taking into account the excellent results with significant improvements in the speech tests and the very high satisfaction of the patients using the new strategy, this first implementation of a fine structure strategy could offer a new quality of hearing with cochlear implants (CIs). Objective. This study consisted of an intra-individual comparison of speech recognition, music perception and patient preference when subjects used two different speech coding strategies with a MedEl Pulsar CI: continuous interleaved sampling (CIS) and the new fine structure processing (FSP) strategy. In contrast to envelope-based strategies, the FSP strategy also delivers subtle pitch and timing differences of sound to the user and is thereby supposed to enhance speech perception in noise and increase the quality of music perception. Patients and methods. This was a prospective study assessing performance with two different speech coding strategies. The setting was a CI programme at an academic tertiary referral centre. Fourteen post-lingually deaf patients using a MedEl Pulsar CI with a mean CI experience of 0.98 years were supplied with the new FSP speech coding strategy. Subjects consecutively used the two different speech coding strategies. Speech and music tests were performed with the previously fitted CIS strategy, immediately after fitting with the new FSP strategy and 4, 8 and 12 weeks later. The main outcome measures were individual performance and subjective assessment of two different speech processors. Results. Speech and music test scores improved statistically significantly after conversion from CIS to FSP strategy. Twelve of 14 patients preferred the new FSP speech processing strategy over the CIS strategy.     

Effect of deep insertion of the cochlear implant electrode array on pitch estimation and speech perception

Conclusion. Deeply inserted electrodes offer the possibility that apical stimulation may improve speech performances. Therefore, deep insertion is reasonable and should be performed in patients with profound or total hearing loss. Objectives. To evaluate the importance of insertion depth beyond 25 mm in a group of cochlear implant patients with deeply inserted electrodes up to 32 mm. Patients and methods. In the first part of the study patients were asked to perform a pitch estimation for channels across the whole length of the electrode array. We evaluated whether pitch discrimination was possible along the whole cochlea and especially in its apical part. Then, the audiological performances of 10 patients were tested in 5 conditions, in which we artificially varied the insertion depth in each patient by activating and deactivating channels. The patients were tested immediately in the new condition to avoid adaptation. Results. The results showed that activating the electrodes in the uppermost region of the cochlea improves speech perception significantly. Furthermore it could be demonstrated that the pitch perceived in the cochlea with electrical stimulation decreases with increasing insertion depth along the whole length of deeply inserted electrode arrays.     

Measurement of pitch perception as a function of cochlear implant electrode and its effect on speech perception with different frequency allocations

Objective: An experiment was conducted to investigate the possibility that speech perception could be improved for some cochlear implant (CI) users by adjustment of the frequency allocation to the electrodes, following assessment of pitch perception along the electrode array.

Study sample: Thirteen adult CI users with MED-EL devices participated in the study.

Design: Pitch perception was assessed for individual CI electrode pairs using the Pitch Contour Test (PCT), giving information on pitch discrimination and pitch ranking for adjacent electrodes. Sentence perception in noise was also assessed with ten different frequency allocations, including the default.

Results: Pitch perception was found to be poorer for both discrimination and ranking scores at either end of the electrode array. A significant effect of frequency allocation was found for sentence scores [F(4.24,38.2)?=?7.14, p?F(4.24,38.2)?=?2.95, p?=?0.03]. Participants with poorer pitch perception at the basal end had poorer scores for some allocations with greater basal shift.

Conclusions: The results suggest that speech perception could be improved for CI users by assessment of pitch perception using the PCT and subsequent adjustment of pitch-related stimulation parameters.     

Person-centred cochlear implant care: Assessing the need for clinic intervention in adults with cochlear implants using a dual approach of an online speech recognition test and a questionnaire

Objectives: To evaluate the feasibility of adults with cochlear implants using an online speech recognition test and questionnaire at home to assess whether they need to come to the clinic or not.

Methods: A prospective single-centre feasibility study evaluating

??An online speech recognition test (digit triplet test (DTT)).

??A long-term follow-up questionnaire to assess aspects that a clinician would ask in a face-to-face appointment.

??A satisfaction questionnaire to assess patient perception of remote speech recognition testing.

??Seventeen people using cochlear implants aged from 34 to 84 years took part.

Results:

??The majority of adults were able and willing to use tools at home to assess if they need to come to the centre.

??The DTT speech reception threshold was repeatable on three occasions within 3 weeks.

??The majority of adults felt positive about testing their own hearing using the DTT at home. However, only a minority (two out of 17) felt they preferred remote testing to clinic testing (the majority was undecided).

Conclusion: The concept of a dual approach of online speech recognition test and questionnaire both done at home has potential to identify which adults with cochlear implants require clinic intervention, although sensitivity and specificity measures are unknown. A clinic visit remains the gold standard of care, but remote care may supplement traditional care pathways.     

Deficits in auditory frequency discrimination and speech recognition in cochlear implant users

Abstract

Objectives

Speech recognition varies considerably following cochlear implantation for reasons that are still poorly understood. Considering the role of frequency discrimination in normal speech recognition, the aim of this study was to investigate the association between deficits in auditory frequency discrimination and speech recognition in cochlear implant users.

Methods

Frequency discrimination thresholds and speech recognition were assessed in a group of 20 cochlear implant users and 16 normally hearing controls.

Results

Based on their results on the speech recognition task, the cochlear implant users were categorized either as proficient (n = 10) or non-proficient users (n = 10). The non-proficient cochlear implant users had poorer auditory frequency discrimination compared to the normal hearing participants and proficient cochlear implant users (both P < 0.05). No significant difference was found between the proficient cochlear implant users and the normally hearing group (P > 0.05). Furthermore, a bivariate correlation analysis revealed a relationship between speech recognition and frequency discrimination.

Conclusions

The present findings suggest an association between auditory frequency discrimination and speech recognition proficiency in cochlear implant users. Although no causal link can be drawn from these data, possible reasons for this association are discussed.     

Speech perception with F0mod,a cochlear implant pitch coding strategy

Objective: The fundamental frequency modulation (F0mod) sound processing strategy was developed to improve pitch perception with cochlear implants. In previous work it has been shown to improve performance in a number of pitch-related tasks such as pitch ranking, familiar melody identification, and Mandarin Chinese tone identification. The objective of the current study was to compare speech perception with F0mod and the standard clinical advanced combination encoder (ACE) strategy. Study sample: Seven cochlear-implant listeners were recruited from the clinical population of the University Hospital Leuven. Design: F0mod was implemented on a real-time system. Speech recognition in quiet and noise was measured for seven cochlear-implant listeners, comparing F0mod with ACE, using three different Dutch-language speech materials. Additionally the F0 estimator used was evaluated physically, and pitch ranking performance was compared between F0mod and ACE. Results: Immediately after switch-on of the F0mod strategy, speech recognition in quiet and noise were similar for ACE and F0mod, for four out of seven listeners. The remaining three listeners were subjected to a short training protocol with F0mod, after which their performance was reassessed, and a significant improvement was found. Conclusions: As F0mod improves pitch perception, for the seven subjects tested it did not interfere with speech recognition in quiet and noise, and has a low computational complexity, it seems promising for implementation in a clinical sound processor.     

Mandarin Chinese speech recognition by pediatric cochlear implant users

Objectives

Because of difficulties associated with pediatric speech testing, most pediatric cochlear implant (CI) speech studies necessarily involve basic and simple perceptual tasks. There are relatively few studies regarding Mandarin-speaking pediatric CI users’ perception of more difficult speech materials (e.g., words and sentences produced by multiple talkers). Difficult speech materials and tests necessarily require older pediatric CI users, who may have different etiologies of hearing loss, duration of deafness, CI experience. The present study investigated how pediatric CI patient demographics influence speech recognition performance with relatively difficult test materials and methods.

Methods

In this study, open-set recognition of multi-talker (two males and two females) Mandarin Chinese disyllables and sentences were measured in 37 Mandarin-speaking pediatric CI users. Subjects were grouped according to etiology of deafness and previous acoustic hearing experience. Group 1 subjects were all congenitally deafened with little-to-no acoustic hearing experience. Group 2 subjects were not congenitally deafened and had substantial acoustic hearing experience prior to implantation. Multiple linear regression analyses were performed within each group using subject demographics such as age at implantation and age at testing.

Results

Pediatric CI performance was generally quite good. For Group 1, mean performance was 82.3% correct for disyllables and 82.8% correct for sentences. For Group 2, mean performance was 76.6% correct for disyllables and 84.4% correct for sentences. For Group 1, multiple linear regression analyses showed that age at implantation predicted disyllable recognition, and that age at implantation and age at testing predicted sentence recognition. For Group 2, neither age at implantation nor age at testing predicted disyllable or sentence recognition. Performance was significantly better with the female than with the male talkers.

Conclusions

Consistent with previous studies’ findings, early implantation provided a significant advantage for profoundly deaf children. Performance for both groups was generally quite good for the relatively difficult materials and tasks, suggesting that open-set word and sentence recognition may be useful in evaluating speech performance with older pediatric CI users. Differences in disyllable recognition between Groups 1 and 2 may reflect differences in adaptation to electric stimulation. The Group 1 subjects developed speech patterns exclusively via electric stimulation, while the Group 2 subjects adapted to electric stimulation relative to previous acoustic patterns.     

语前聋儿童人工耳蜗植入效果的评估

目的探索语前聋儿童人工耳蜗植入效果的评估方法.方法受试者为18名接受人工耳蜗植入的语前聋儿童,耳蜗植入时平均年龄6岁.按人工耳蜗使用时间长短分为四个阶段进行评估:第一阶段18名患儿,使用人工耳蜗1～12个月;第二阶段12名,使用人工耳蜗13～24个月;第三阶段8名,使用人工耳蜗25～36个月;第四阶段6名,使用人工耳蜗在36个月以上.描述性分析,以问卷的形式了解儿童在人工耳蜗植入后声音接受、言语表达及行为等方面的变化;言语测试,进行言语识别能力和发声能力测试.结果第一阶段患儿,能够感知和辨别来自家庭和环境中的声音;第二阶段患儿,封闭项词识别率是51%,开放项词识别开始启动;第三阶段患儿,封闭项词识别率达到72%,开放项词识别率是40%,能正确发出的单词数是42%;第四阶段患儿,封闭项词识别率和开放项词识别率分别达到84%和53%,能正确发出的单词数达62%,部分患儿已有自发的口语表达.结论人工耳蜗植入对语前聋患儿的言语发育有帮助,患儿的言语能力随着人工耳蜗使用时间的推移不断进步.     

Auditory neuropathy in systemic sclerosis: a speech perception and evoked potential study before and after cochlear implantation

We report the results of speech perception and electrophysiological evaluation of the auditory periphery performed before and after cochlear implantation in a 18-year-old girl with systemic sclerosis (SS) who presented the clinical picture of auditory neuropathy. Transtympanic electrocochleography (ECochG) in response to 0.1 ms clicks was recorded 1 month before cochlear implantation on both sides while the electrically evoked neural response was obtained intraoperatively in the right ear through cochlear implant stimulation. The ECochG recordings revealed the presence of the cochlear microphonic with normal amplitude and threshold on both sides. A compound action potential was only detected in the left ear at high stimulation intensity, while the electrically evoked neural response was clearly identifiable at all the recording sites during neural response telemetry. Standardized speech perception tests were performed 1 month before cochlear implantation and several times after cochlear implant connection. Speech perception scores were close to chance before cochlear implantation while they showed a remarkable improvement thereafter. The results of this study show that subjects affected by SS could present the clinical picture of auditory neuropathy which is possibly underlain by lesions involving the distal portion of auditory nerve fibers and/or synapses with inner hair cells. The restoration of synchronous neural discharge could be achieved by electrical stimulation through cochlear implant.