A longitudinal study of speech perception skills and device characteristics of adolescent cochlear implant users

Short-term overstimulation affects peripheral but not central excitability in an animal model of cochlear implantation

Objective: A smallbut persistent proportion of individuals do not gain the expected benefit from cochlear implants(CI). A step-change in the understanding of factors affecting outcomes could come through data science. This study evaluates clinical data capture to assess the quality and utility of Cl user's health records for data science, by assessing the recording of otitis media. Otitis media was selected as it is associated with the development of sensorineural hearing loss and may affect cochlear implant outcomes.Methods: A retrospective service improvement project ·evaluating the medical records of 594 people with a Cl under the care of the University of Southampton Auditory Implant Service between 2014 and 2020.Results: The clinicalrecords are suitable for data science research. Of the cohort studied 20% of Adults and more than 40% of the paediatric cases have a history of middle ear inflammation.Discussion: Data science has potentialto improve cochlear implant outcomes and improve understanding of the mechanisms underlying poor performance, through retrospective secondary analysis of real-world data.Conclusion: Implant centres and the British Cochlear Implant Group National Hearing Implant Registry are urged to consider the importance of consistently and accurate recording of patient data over time for each Cl user. Data where links to hearing loss have been identified, such as middle ear inflammation, may be particularly valuable in future analyses and to inform clinical trials.

Listening Difficulties of Children With Cochlear Implants in Mainstream Secondary Education

OBJECTIVES

Previous research has shown that children with cochlear implants (CIs) encounter more communication difficulties than their normal-hearing (NH) peers in kindergarten and elementary schools. Yet, little is known about the potential listening difficulties that children with CIs may experience during secondary education. The aim of this study was to investigate the listening difficulties of children with a CI in mainstream secondary education and to compare these results to the difficulties of their NH peers and the difficulties observed by their teachers.

DESIGN

The Dutch version of the Listening Inventory for Education Revised (LIFE-R) was administered to 19 children (mean age = 13 years 9 months; SD = 9 months) who received a CI early in life, to their NH classmates (n = 239), and to their teachers (n = 18). All participants were enrolled in mainstream secondary education in Flanders (first to fourth grades). The Listening Inventory for Secondary Education consists of 15 typical listening situations as experienced by students (LIFEstudent) during class activities (LIFEclass) and during social activities at school (LIFEsocial). The teachers completed a separate version of the Listening Inventory for Secondary Education (LIFEteacher) and Screening Instrument for Targeting Educational Risk.

RESULTS

Participants with CIs reported significantly more listening difficulties than their NH peers. A regression model estimated that 75% of the participants with CIs were at risk of experiencing listening difficulties. The chances of experiencing listening difficulties were significantly higher in participants with CIs for 7 out of 15 listening situations. The 3 listening situations that had the highest chance of resulting in listening difficulties were (1) listening during group work, (2) listening to multimedia, and (3) listening in large-sized classrooms. Results of the teacher's questionnaires (LIFEteacher and Screening Instrument for Targeting Educational Risk) did not show a similar significant difference in listening difficulties between participants with a CI and their NH peers. According to teachers, NH participants even obtained significantly lower scores for staying on task and for participation in class than participants with a CI.

CONCLUSIONS

Although children with a CI seemingly fit in well in mainstream schools, they still experience significantly more listening difficulties than their NH peers. Low signal to noise ratios (SNRs), distortions of the speech signal (multimedia, reverberation), distance, lack of visual support, and directivity effects of the microphones were identified as difficulties for children with a CI in the classroom. As teachers may not always notice these listening difficulties, a list of practical recommendations was provided in this study, to raise awareness among teachers and to minimize the difficulties.

Longitudinal Speech Recognition in Noise in Children: Effects of Hearing Status and Vocabulary

Objectives: The aims of the current study were: (1) to compare growth trajectories of speech recognition in noise for children with normal hearing (CNH) and children who are hard of hearing (CHH) and (2) to determine the effects of auditory access, vocabulary size, and working memory on growth trajectories of speech recognition in noise in CHH. Design: Participants included 290 children enrolled in a longitudinal study. Children received a comprehensive battery of measures annually, including speech recognition in noise, vocabulary, and working memory. We collected measures of unaided and aided hearing and daily hearing aid (HA) use to quantify aided auditory experience (i.e., HA dosage). We used a longitudinal regression framework to examine the trajectories of speech recognition in noise in CNH and CHH. To determine factors that were associated with growth trajectories for CHH, we used a longitudinal regression model in which the dependent variable was speech recognition in noise scores, and the independent variables were grade, maternal education level, age at confirmation of hearing loss, vocabulary scores, working memory scores, and HA dosage. Results: We found a significant effect of grade and hearing status. Older children and CNH showed stronger speech recognition in noise scores compared to younger children and CHH. The growth trajectories for both groups were parallel over time. For CHH, older age, stronger vocabulary skills, and greater average HA dosage supported speech recognition in noise. Conclusion: The current study is among the first to compare developmental growth rates in speech recognition for CHH and CNH. CHH demonstrated persistent deficits in speech recognition in noise out to age 11, with no evidence of convergence or divergence between groups. These trends highlight the need to provide support for children with all degrees of hearing loss in the academic setting as they transition into secondary grades. The results also elucidate factors that influence growth trajectories for speech recognition in noise for children; stronger vocabulary skills and higher HA dosage supported speech recognition in degraded situations. This knowledge helps us to develop a more comprehensive model of spoken word recognition in children.

The Estimated Electrode-Neuron Interface in Cochlear Implant Listeners Is Different for Early-Implanted Children and Late-Implanted Adults

Cochlear implant (CI) programming is similar for all CI users despite limited understanding of the electrode-neuron interface (ENI). The ENI refers to the ability of each CI electrode to effectively stimulate target auditory neurons and is influenced by electrode position, neural health, cochlear geometry, and bone and tissue growth in the cochlea. Hearing history likely affects these variables, suggesting that the efficacy of each channel of stimulation differs between children who were implanted at young ages and adults who lost hearing and received a CI later in life. This study examined whether ENI quality differed between early-implanted children and late-implanted adults. Auditory detection thresholds and most comfortable levels (MCLs) were obtained with monopolar and focused electrode configurations. Channel-to-channel variability and dynamic range were calculated for both types of stimulation. Electrical field imaging data were also acquired to estimate levels of intracochlear resistance. Children exhibited lower average auditory perception thresholds and MCLs compared with adults, particularly with focused stimulation. However, neither dynamic range nor channel-to-channel threshold variability differed between groups, suggesting that children’s range of perceptible current was shifted downward. Children also demonstrated increased intracochlear resistance levels relative to the adult group, possibly reflecting greater ossification or tissue growth after CI surgery. These results illustrate physical and perceptual differences related to the ENI of early-implanted children compared with late-implanted adults. Evidence from this study demonstrates a need for further investigation of the ENI in CI users with varying hearing histories.

Electrical dynamic range is only weakly associated with auditory performance and speech recognition in long-term users of cochlear implants

OBJECTIVE

The electrical dynamic range (EDR) has been suggested to be related to auditory performance in cochlear implant (CI) users. However, few reports have evaluated postlingual CI users who have used CIs for long periods in comparison with prelingual CI users. Here, we evaluated auditory perception and speech performance in terms of the EDR in long-term CI users. The EDR, and auditory and speech performances, were compared between pre- and post-lingual CI users.

METHODS

We enrolled all patients who received CIs from April 2000 to December 2010 at Seoul National University Hospital, and who had ≥5 years of experience with CIs. The EDRs affording subjective responses at the threshold level (T-level) and comfortable level (C-level) were analyzed in terms of their relationships with pure tone audiometry levels, speech evaluation scores, including those on the Phonetically Balanced (PB) Word List test, vowel and consonant tests, a sentence test, and the Korean version of the Central Institute for the Deaf (K-CID) test; we also calculated Category in Auditory Performance (CAP) scores.

RESULTS

We found no significant difference in the average EDR, CAP, K-CID, PB word, consonant, or vowel scores between pre- and post-lingual CI users. The EDR was weakly associated with the PB word (P = 0.003, r = 0.462) and consonant scores (P = 0.005, r = 0.438). Other speech evaluations, such as the CAP, K-CID, and vowel scores, were not significantly associated with the EDR T-level. We found no association between pure tone thresholds at 0.5, 1, or 2 kHz, and the speech evaluation scores or EDRs of low-, middle-, or high-frequency channels.

CONCLUSIONS

The EDR was only weakly associated with speech performance, such as scores on consonant and PB word tests in long-term CI users, irrespective of pre- or post-lingual deafness status.

Level of emotion comprehension in children with mid to long term cochlear implant use: How basic and more complex emotion recognition relates to language and age at implantation

OBJECTIVES

The current study was designed with three main aims: To document the level of emotional comprehension skills, from basic to more complex ones, reached by a wide sample of cochlear implant (CI) deaf children with at least 36 months of device use; To investigate subjective and audiological factors that can affect their emotional development; To identify, if present, a "critical age", in which early intervention might positively affect adequate emotional competence development.

DESIGN

This is an observational cohort study. Children with congenital severe/profound deafness were selected based on: aged by 4-11 years, minimum of 36 months of CI use, Italian as the primary language in the family; normal cognitive level and absence of associated disorders or socio-economic difficulties. Audiological characteristics and language development were assessed throughout standardized tests, to measure speech perception in quiet, lexical comprehension and production. The development of emotions' understanding was assessed using the Test of Emotion Comprehension (TEC) of Pons and Harris, a hierarchical developmental model, where emotion comprehension is organized in 3 Stages (external, mental and reflective). Statistical analysis was accomplished via the Spearman Rank Correlation Coefficient, to study the relationship between the personal and audiological characteristics; a multivariate linear regression analysis was carried out to find which variables were better associated with the standardized TEC values; a chi-squared test with Yate's continuity correction and Mann-Whitney U test were used to account for differences between continuous variables and proportions.

RESULTS

72 children (40 females, 32 males) with a mean age of 8.1 years were included. At TEC score, 57 children showed normal range performances (79.17% of recipients) and 15 fell below average (20.83% of recipients). The 16.63% of older subjects (range of age 8-12 years) didn't master the Stage 3 (reflective), which is normally acquired by 8 years of age and failed 2 or all the 3 items of this component. Subjects implanted within 18 months of age had better emotion comprehension skills. TEC results were also positively correlated with an early diagnosis, a longer implant use, better auditory skills and higher scores on lexical and morphosintactic tests. On the contrary, it was negatively correlated with the presence of siblings and the order of birth. The gender, the side and the severity of deafness, type of implant and strategy were not correlated.

CONCLUSIONS

Early implanted children have more chance to develop adequate emotion comprehension, especially when the complex aspects are included, due to the very strong link between listening and language skills and emotional development. Furthermore, longer CI auditory experience along with early intervention allows an adequate communication development which positively influences the acquisition of such competencies.

Acoustic temporal modulation detection in normal-hearing and cochlear implanted listeners: effects of hearing mechanism and development

Temporal modulation detection ability matures over many years after birth and may be particularly sensitive to experience during this period. Profound hearing loss during early childhood might result in greater perceptual deficits than a similar loss beginning in adulthood. We tested this idea by measuring performance in temporal modulation detection in profoundly deaf children and adults fitted with cochlear implants (CIs). At least two independent variables could constrain temporal modulation detection performance in children with CIs: altered encoding of modulation information due to the CI-auditory nerve interface, and atypical development of central processing of sound information provided by CIs. The effect of altered encoding was investigated by testing subjects with one of two different hearing mechanisms (normal hearing vs. CI) and the effect of atypical development was studied by testing two different age groups. All subjects were tested for their ability to detect acoustic temporal modulations of sound amplitude. A comparison of the slope, or cutoff frequency, of the temporal modulation transfer functions (TMTFs) among the four subject groups revealed that temporal resolution was mainly constrained by hearing mechanism: normal-hearing listeners could detect smaller amplitude modulations at high modulation frequencies than CI users. In contrast, a comparison of the height of the TMTFs revealed a significant interaction between hearing mechanism and age group on overall sensitivity to temporal modulation: sensitivity was significantly poorer in children with CIs, relative to the other three groups. Results suggest that there is an age-specific vulnerability of intensity discrimination or non-sensory factors, which subsequently affects sensitivity to temporal modulation in prelingually deaf children who use CIs.

The Music Experiences and Attitudes Of A First Cohort of Prelingually-Deaf Adolescents and Young Adults CI Recipients

The purpose of this study was to examine the musical engagement (participation and attitude) of pediatric CI recipients who were implanted during early childhood and who have reached age 15 or older. A questionnaire was administered to a group of 31 prelingually deaf CI users who receive annual follow up services and assessment in a clinical research center. The questionnaire was used to examine involvement in and attitudes toward music in school, the community, and in the home; social affiliation (hearing, Deaf, both) and mode of communication (oral, manual, both) were also examined. Despite the technical limitations of cochlear implants in transmitting pitch, melody, and tone quality, over two thirds of this sample described music as being important or very important in their lives. A high level of past and present familial involvement in music was associated with higher levels of current involvement and importance of music in the lives of adolescent and young adult CI users. Comparisons were noted with data from prior studies of persons with hearing loss who were non-CI users.