Open-set Speech Perception Abilities Research Articles

Assistive Devices for Patients with Auditory Neuropathy: Hearing Aid Use

Auditory neuropathy (AN) is a hearing disorder characterized by disruption of temporal coding of acoustic signals in the auditory nerve resulting from lesions involving auditory nerve fibers, the inner hair cells, or their synapses with auditory nerve terminals. Disruption of auditory nerve discharge underlies both the absence of auditory brainstem responses (ABRs) and impairment of speech perception. AN may be related to genetic disorders or result from a wide range of other etiologies. It can be identified either as an isolated disorder (isolated AN) or associated with multisystem involvement (non-isolated AN). Effectiveness and choice of assistive devices depend crucially upon etiology, site of lesion, and stage of the disease. Cochlear implants constitute an effective rehabilitative tool able to restore speech perception in many patients with genetic AN, especially those affected by the isolated form of the disorder. Some children with isolated AN have proved to be good hearing aid users, showing satisfactory open-set speech perception abilities in the aided condition. Over 50% of children discharged from neonatal intensive care units showing the electrophysiological profile of AN (absent ABRs, presence of otoacoustic emissions) benefit from hearing aid use, the provision of amplification resulting in remarkable improvement in speech perception. It can be concluded that differences in cochlear implant outcome or hearing aid use in patients with AN are related to the pathophysiological mechanisms underlying alteration of auditory nerve discharge associated with individual etiologies.

Stimulation Rate Reduction and Auditory Development in Poorly Performing Cochlear Implant Users With Auditory Neuropathy

Patients with auditory neuropathy spectrum disorder (ANSD) exhibit altered neural synchrony in response to auditory stimuli. It has been hypothesized that a slower rate of electrical stimulation in programming strategies for cochlear implant (CI) users with ANSD may enhance development of neural synchrony and speech perception abilities. Retrospective case series. Tertiary otologic practice. Twenty-two patients with ANSD underwent CI. Patients with complete postoperative audiometric data and at least 2 years of follow-up were included in further analysis. Thirteen patients patients met inclusion criteria. Five "poorly performing" CI recipients with ANSD who had not developed closed-set speech perception abilities despite at least 2 years of implant use underwent implant programming to lower the neural stimulation rate. Speech perception abilities over time using parent questionnaire, closed-set testing, and open-set measures. A high incidence of comorbid conditions was present in the poor performers, including cognitive delay (n = 2), motor delay (n = 3), and autism spectrum disorder (n = 1). The median time to rate slowing in 5 poor performers was 29 months after implant activation. Three of 5 patients achieved closed-set speech perception scores higher than 60% after 6 to 16 months of implant use at the slower rates. At last follow-up (median, 42 mo), no poor performer had yet achieved open-set speech perception abilities. Of all CI recipients with ANSD included in analysis, open-set speech perception abilities developed in 46% (6/13). In CI recipients with ANSD who demonstrate limited auditory skills development despite prolonged implant use, lowering the stimulation rate may facilitate acquisition of closed-set speech perception abilities. Further efforts on the study of programming parameters in ANSD patients with CIs are necessary to maximize auditory development in this patient population.

Cochlear Implant–Evoked Cortical Activation in Children With Cochlear Nerve Deficiency

To report the results of cochlear implant-elicited cortical auditory evoked potentials (eCAEP) in children with cochlear nerve deficiency (CND). Case control series. Tertiary academic referral center. Seven children with CND that have a cochlear implant in their affected ear. Four children without CND served as controls. eCAEPs were elicited by activation of individual cochlear implant electrodes. Onset responses (P1-N1-P2 complex). Three of 7 CND children demonstrated eCAEP responses across a broad range of electrodes despite having limited or no open set speech perception abilities using their implants. Two of these children had eCAEPs that were characterized by substantial variability in latency, amplitude, and number of electrodes with identifiable responses. The remaining 4 ears with CND and poor speech perception had multiphasic responses that are inconsistent with eCAEPs. Non-CND ears with excellent speech perception abilities demonstrated robust responses on all electrodes stimulated. Abent eCAEP responses were indicative of poor open-set speech perception skills in all cases. However, eCAEP onset responses were measurable in some children with imaging evidence of CND, indicating probable cochlear nerve hypoplasia rather than aplasia. That some children with CND and poor speech perception had robust eCAEPs in some instances makes this particular measure of limited use for predicting good speech perception outcomes after cochlear implantation in these children. The origin of multiphasic responses remains to be determined but may be of somatosensory origin in some instances.

Cochlear implantation in children with cochlear aplasia

Conclusion: Children with cochlear aplasia can achieve favorable speech perception abilities from cochlear implantation (CI) by inserting an electrode array into the vestibule if an audiological response is reliably demonstrated before surgery by behavioral audiometry and objective measures. Objectives: The purpose of this study was to evaluate the surgical outcome of CI in children with cochlear aplasia. Methods: The medical records of 454 children who underwent CI at the Dong-A University Hospital between January 1994 and September 2011 were reviewed. The prevalence of cochlear aplasia and the preoperative evaluations, operative findings, and postoperative speech perception abilities of implanted children with cochlear aplasia were evaluated. Results: The implanted children with cochlear aplasia accounted for 2% of those with inner ear malformations and 0.4% of all pediatric cochlear implantees. They showed audiological responses in preoperative electrophysiologic tests, and the eighth nerve was present in magnetic resonance imaging. The electrode array was inserted into the vestibule through an oval window after removing the stapes or through a transmastoid labyrinthotomy site. Electrical compound action potential and electrical auditory brainstem response tests showed clear neural responses after implantation. The hearing thresholds of the implanted ear improved to 25 dB HL and the children achieved significant open set speech perception abilities.

Cochlear implantation in children with postlingual hearing loss

Although it is clear that early auditory stimulation through cochlear implantation (CI) has been shown to improve speech and language development trajectories for children with prelingual hearing loss, data supporting implantation in postlingual children are mostly lacking. The purpose of this study was to characterize speech perception abilities following CI in a group of children with previously well-developed language abilities. Retrospective analysis. Twenty-eight hearing-impaired children who received CIs were selected for study based on the presence of well-developed spoken language skills before implantation. Fifteen children with prelingual hearing loss served as a control group. Speech perception skills were assessed using developmentally appropriate measures. Children with postlingual hearing loss showed a statistically significant improvement in open-set speech perception scores as early as 6 months following CI, whereas prelingual children demonstrated significant improvements only after 24 months of use. Despite these early disparities in performance, the two groups were similar 36 months after implantation and beyond (60 months of implant use). Children with well-developed language abilities before CI showed substantial (and statistically significant) early improvements in open-set speech perception abilities following implantation that continued beyond 2 years of follow-up. These results suggest that postlingual children are excellent candidates for CI.

Cochlear Implantation in Children with Auditory Neuropathy Spectrum Disorder

To report the patient's characteristics, preoperative audiological profiles, surgical outcomes, and postoperative performance for children with auditory neuropathy spectrum disorder (ANSD) who ultimately received cochlear implants (CIs). Prospective, longitudinal study of children with ANSD who received CIs after a stepwise management protocol that included electrophysiologic and medical assessment, documentation of behavioral audiometric thresholds and subsequent fitting of amplification according to Desired Sensation Level targets, auditory-based intervention with careful monitoring of skills development and communication milestones, and finally implantation when progress with the use of acoustic amplification was insufficient. Of 140 children with ANSD, 52 (37%) received CIs in their affected ears (mean duration of use of 41 mos). Many of these children were born prematurely (42%) and impacted by a variety of medical comorbidities. More than one third (38%) had abnormal findings on preoperative magnetic resonance imaging of the brain and inner ear, and 81% had a greater than severe (>70 dB HL) degree of hearing loss before implantation. Although 50% of the implanted children with ANSD demonstrated open-set speech perception abilities after implantation, nearly 30% of them with >6 months of implant experience were unable to participate in this type of testing because of their young age or developmental delays. No child with cochlear nerve deficiency (CND) in their implanted ear achieved open-set speech perception abilities. In a subgroup of children, good open-set speech perception skills were associated with robust responses elicited on electrical-evoked intracochlear compound action potential testing when this assessment was possible. This report shows that children with ANSD who receive CIs are a heterogeneous group with a wide variety of impairments. Although many of these children may ultimately benefit from implantation, some will not, presumably because of a lack of electrical-induced neural synchronization, the detrimental effects of their other associated conditions, or a combination of factors. When preoperative magnetic resonance imaging reveals central nervous system pathology, this portends a poor prognosis for the development of open-set speech perception, particularly when CND is evident. These results also show that electrical-evoked intracochlear compound action potential testing may help identify those children who will develop good open-set speech perception. Instead of recommending CI for all children with electrophysiologic evidence of ANSD, the stepwise management procedure described herein allows for the identification of children who may benefit from amplification, those who are appropriate candidates for cochlear implantation, and those who, because of bilateral CND, may not be appropriate candidates for either intervention.

Self-Reported Listening Habits and Enjoyment of Music among Adult Cochlear Implant Recipients

We sought to assess the associations between self-reported listening habits and enjoyment of music, and the following variables: age at implantation, gender, prelingual versus postlingual deafness, duration of deafness, duration of cochlear implant (CI) use, type of CI, speech coding strategy, and speech perception abilities. A questionnaire on listening habits and enjoyment of music before the onset of deafness and after implantation was sent to 85 adult CI recipients who had been using the devices for at least 6 months. Of the 53 responders, 39 (73.6%) listened to music after implantation. Listening to music was not significantly related to age at implantation, gender, duration of deafness, duration of CI use, type of CI device, speech coding strategy, or open-set speech perception abilities. The 14 nonlisteners were postlingually deafened. The ratings of enjoyment were the same for 22.6% of patients, improved for 26.4%, and worse for 50.9%. Only 2 of 13 patients who played a musical instrument and 14 of 24 patients who sang before the onset of deafness resumed their musical activities. Despite the decline in listening habits and in the enjoyment of music after cochlear implantation, most patients do listen to music. The changes in listening habits and enjoyment were not related to the selected background variables.

Cochlear Implantation in Children with Inner Ear Malformations

The aim of this study was to assess the outcomes of cochlear implantation in children with inner ear malformations (IEMs). A retrospective review of 212 children who received implants from September 1994 to May 2004 was performed. Forty-six of them had radiologic evidence of IEMs. The preoperative evaluations, intraoperative findings, postoperative complications, and performance outcomes were analyzed. For the comparative analysis of performance outcomes, the children with IEMs were matched and compared with children with a normal inner ear who had received implants. Statistical analysis was performed with a repeated-measures analysis of variance. All of the children were studied with computed tomography and magnetic resonance imaging. Three-dimensional volume rendering of magnetic resonance images was performed in cases that were difficult to interpret because of structural complexity. The operative findings included aberrant facial nerves in 2 children and cerebrospinal fluid gushers in 22 children. Intraoperative fluoroscopic examination was performed to evaluate electrode placement. There were no serious postoperative complications. All children with IEMs achieved open-set speech perception abilities, except for the children with a narrow internal auditory canal (IAC), and showed progressive improvement of their speech perception abilities over time. There were no statistically significant differences in performance measured by the Common Phrases test between the 2 groups. Although the repeated-measures analysis of variance indicated that children with IEMs performed more poorly than those with a normal inner ear on the Phonetically Balanced Kindergarten test for phonemes, statistical significance was not found at 2 years after implantation. The children with a narrow IAC benefited from the implantation and used the device every day, although their speech perception abilities were limited. The results of the present study show that cochlear implantation can be performed relatively safely in deaf children with IEMs and that they receive considerable benefit from their implants. Substantial benefit can be expected from implantation in children with most kinds of IEMs, except for a narrow IAC, which is often associated with limited results.

Effect of age at cochlear implantation on open-set word recognition in Mandarin speaking deaf children

The purpose of this study was to determine whether age at cochlear implantation influences open-set speech perception in children after long-term use of the implant device. Twenty-eight congenitally deafened children, receiving implants of Nucleus CI24M devices, were divided into two groups: (1) CI < 3: those who received implants before 3 years of age and (2) CI > 3: those who received implants after 3 years of age. We compared open-set speech perception in CI < 3 and CI > 3 after 4-5 years of device use. Speech perception tests were conducted using the Mandarin Lexical Neighborhood Test (M-LNT). Unpaired t-test was applied for statistical analysis, and p < 0.05 was considered significant. In CI < 3, the average of percent correct was 80.0 +/- 8.8 and 70.5 +/- 9.2% on, respectively, the easy and hard versions of the M-LNT. By contrast, in CI > 3, the average percent correct was 62.5 +/- 19.9 and 59.1 +/- 15.2%, respectively. Regardless of the M-LNT version used, CI < 3 performed significantly better than CI > 3 (easy, p = 0.005 versus hard, p = 0.022). The present investigation demonstrated that age at implantation influences open-set speech perception of cochlear implanted children 4-5 years after device connection. Implantation before 3 years of age promotes the development of open-set speech perception abilities in congenitally deafened children.

Speech perception and cortical event related potentials in children with auditory neuropathy.

1) To investigate the unaided and aided speech perception abilities of children with auditory neuropathy (AN) and to compare their performance to children with sensorineural hearing loss. 2) To establish whether cortical event related potentials (ERPs) could be recorded in children with AN, and to determine the relationship between the presence of these responses and speech perception. Unaided and aided speech perception assessments (PBK words), and cortical-ERP testing was carried out in a group of 18 children with AN. Data also were obtained from a cohort of age and hearing level matched children with sensorineural hearing loss. The speech perception performance of the 15 children with AN able to complete a PBK-word assessment, fell into two distinct categories. The children either showed no open-set speech perception ability (7/15 cases), or performance levels similar to their sensorineural counterparts (8/15 cases). Approximately 50% of children with AN showed ERPs of normal latency, amplitude and morphology. In all cases, response presence (at normal latencies) was consistent with reasonable speech perception ability, and response absence was consistent with negligible speech perception. In approximately 50% of children with auditory neuropathy, the provision of amplification results in significant open-set speech perception improvements. The results confirm the previously published reports that speech perception ability cannot be reliably estimated from the behavioral audiogram in children with AN. Obligatory ERP test results may offer a means of predicting perceptual skills in newly diagnosed youngsters as the presence of ERPs (with age-appropriate latency and morphology) was correlated with significant open set speech perception abilities and amplification benefit. The absence of the ERP in contrast, indicated profound hearing disability evidenced by profound hearing loss and/or extremely poor speech perception.

Speech perception in children using cochlear implants: prediction of long-term outcomes

A group of 102 children using the Nucleus multichannel cochlear implant were assessed for open-set speech perception abilities at six-monthly intervals following implant surgery. The group included a wide range of ages, types of hearing loss, ages at onset of hearing loss, experience with implant use and communication modes. Multivariate analysis indicated that a shorter duration of profound hearing loss, later onset of profound hearing loss, exclusively oral/aural communication and greater experience with the implant were associated with better open-set speech perception. Developmental delay was associated with poorer speech perception and the SPEAK signal coding scheme was shown to provide better speech perception performance than previous signal processors. Results indicated that postoperative speech perception outcomes could be predicted with an accuracy that is clinically useful.

Speech perception in children using cochlear implants: prediction of long-term outcomes

A group of 102 children using the Nucleus multichannel cochlear implant were assessed for open-set speech perception abilities at six-monthly intervals following implant surgery. The group included a wide range of ages, types of hearing loss, ages at onset of hearing loss, experience with implant use and communication modes. Multivariate analysis indicated that a shorter duration of profound hearing loss, later onset of profound hearing loss, exclusively oral/aural communication and greater experience with the implant were associated with better open-set speech perception. Developmental delay was associated with poorer speech perception and the SPEAK signal coding scheme was shown to provide better speech perception performance than previous signal processors. Results indicated that postoperative speech perception outcomes could be predicted with an accuracy that is clinically useful.

Cochlear implantation: long-term functional outcomes

The aim of this study is to evaluate the speech perception of profoundly deaf children following cochlear implantation. Material and methods: A prospective study was undertaken on a consecutive group of 138 children. Fifty children (36.3%) were deafened by meningitis, 75 (54.3%) were congenitally deaf, and 13 children (9.4%) were deafened by other causes. All children had received the Nucleus-22 multi-channel cochlear implant and followed a standard rehabilitation programme. No child was lost to follow-up and there were no exclusions from the study. The Iowa Matrix Closed Set Sentence Test and Connected Discourse Tracking were used to assess closed and open set speech perception respectively. Results: On the Iowa Matrix Test, the median score was 0% before implantation, 0% at 1 year, 85% at 2 years, 99% at 3 years, and 100% at 4 and 5 years following cochlear implantation. On Connected Discourse Tracking the median score was 0 words per min (wpm) before implantation, 3 wpm at 1 year, 10 wpm at 2 years, 22 wpm at 3 years, 34 wpm at 4 years and 37 wpm at 5 years following cochlear implantation. Conclusion: A comprehensive rehabilitation programme can help profoundly deaf children develop significant closed set speech perception abilities in the following 2–3 years after cochlear implantation. However, open set speech perception abilities need significantly more time to develop and they do not reach a plateau even 5 years after cochlear implantation.