Auditory Outcomes Following Cochlear Implantation in Children with Unilateral Hearing Loss

Abstract

Objective:

Unilateral hearing loss (UHL) in children is associated with speech and language delays. Cochlear implantation (CI) is currently the only rehabilitative option that restores binaural hearing. This study aims to describe auditory outcomes in children who underwent CI for UHL and to determine the association between duration of hearing loss and auditory outcomes.

Study Design:

Retrospective case series.

Setting:

Three tertiary-level, academic institutions.

Patients:

Children <18 years with UHL who underwent CI between 2018 and 2021.

Intervention:

Cochlear implantation.

Main Outcome Measures:

Speech perception and Speech, Spatial and Qualities of Hearing Scale (SSQ) were assessed postimplantation. Scores >50% on speech perception and SSQ scores >8 points were considered satisfactory. Associations between duration of UHL and implantation age and outcomes were assessed using Spearman’s rank correlation.

Results:

Of the 38 children included, mean age at CI was 7.9 ± 3.2 years and mean UHL duration was 5.0 ± 2.8 years. Mean datalogging was 8.1 ± 3.1 hours/day. Mean auditory testing scores were SSQ, 7.9 ± 1.2; BABY BIO, 68.1 ± 30.2%; CNC, 38.4 ± 28.4%; WIPI, 52.5 ± 23.1%. Scores >50% on CNC testing were achieved by 40% of patients. SSQ scores >8 points were reported by 78% (7/9) of patients. There were no significant correlations between UHL duration and auditory outcomes.

Conclusion:

Overall, children with UHL who undergo CI can achieve satisfactory speech perception scores and SSQ scores. There were no associations between duration of hearing loss and age at implantation with auditory outcomes. Multiple variables may impact auditory outcomes, including motivation, family support, access to technology, and consistent isolated auditory training postactivation and should be taken into consideration in addition to age at implantation and duration of UHL in determination of CI candidacy.

INTRODUCTION

Unilateral hearing loss (UHL) occurs in 3–6% of children and is associated with higher rates of speech and language delays, educational assistance requirements, and grade failure (1–3). In children with severe-to-profound UHL (single-sided deafness; SSD), for which traditional hearing aids may be inadequate, bone anchored aids or contralateral routing of signal (CROS) hearing aids can be used for auditory rehabilitation (4). However, these modalities do not confer binaural hearing and its associated benefits. Cochlear implantation (CI) is currently the only rehabilitative option that restores binaural hearing and was approved in 2019 by the U.S. Food and Drug Administration (FDA) for children aged 5 years and older with SSD.

A recent meta-analysis of 119 children with UHL found that CI was associated with improved audiological and patient-reported outcomes (5). Notably, the duration of hearing loss among limited users was higher than among regular users, as was the age at implantation. These results suggest that longer durations of hearing loss and older age at implantation may lead to poorer outcomes and device limited use. However, these findings are based on a small number of limited users (28% of cohort). Other variables can impact CI outcomes that were not accounted for, such as socioeconomic factors, poverty level, and maternal education (6–8). Additionally, auditory and speech/language rehabilitation can facilitate CI outcomes (9,10).

There are limited data on auditory outcomes in children with UHL who undergo CI, and the impact of duration of hearing loss and the age of implantation are not well characterized. Prior studies have been limited by small cohorts and heterogeneous study populations (11–15). This study aims to describe the auditory outcomes of children with UHL who underwent CI and further determine the association between duration of hearing loss and age at implantation with auditory outcomes. We hypothesize that children with UHL can achieve satisfactory auditory outcomes and perceive quality of hearing advantages after CI, including children with longer duration of hearing loss and older age at CI. These study findings may inform clinicians of optimal timing of cochlear implantation in children with UHL and aid in patient selection for CI. Interventions that can optimize outcomes in this patient population will also be discussed.

METHODS

Patient Selection

This retrospective cohort study included pediatric patients who underwent CI for UHL between 2018 and 2021 at three tertiary-level, academic institutions. The study was approved by the Institutional Review Boards at Cleveland Clinic Foundation, University of Iowa Hospitals and Clinics, and Virginia Mason Medical Center. Patients were included if they were <18 years at CI and had UHL that met audiological, medical, and speech/language criteria for CI. Children with residual low-frequency hearing but met audiological criteria for undergoing CI were also included. Duration of hearing loss was defined as time between age at diagnosis of hearing loss and age at CI. Patients with incomplete audiological or speech/language testing results, follow-up <30 days were excluded. All patients are recommended to follow up for auditory–verbal therapy and were given therapy recommendations for home. Demographic, audiometric, treatment, and outcome variables were collected from the electronic medical records (EMR). CT and/or MRI imaging was available for all patients. Patients were considered CI limited users if mean implant datalogging was <8 hours/day (16–18).

Speech-Perception Testing Methods

Outcome measures included Pediatric AzBio (BABY BIO) sentences in quiet, consonant–nucleus–consonant (CNC) monosyllabic words, and Word Intelligibility by Picture Identification (WIPI). For audiologic testing, the implanted ear was isolated either by using direct connect or by masking the contralateral ear. WIPI was delivered through live voice at 55 decibels hearing level (dBHL) when presented in the sound field, whereas BABY BIO and CNC were administered via recorded stimuli at 60 A-weighted decibels (dBA) at 0° azimuth. BABY BIO, WIPI, and CNC scores were calculated as percentage correct out of a total score of 100%. Currently, patients with CNC scores less than 50% on cochlear implant candidacy evaluation have been shown to be appropriate for candidates for CI, suggesting this as a marker of poor auditory functioning of the ear (19,20). Therefore, scores >50% on CNC were chosen as meeting adequacy of auditory outcome in this study.

The Speech, Spatial and Qualities of Hearing Scale (SSQ) Questionnaire

TThe adult version of the SSQ questionnaire, a patient-reported outcomes measure for hearing, was delivered in person or through patient communication using the EMR to parents of the study patients. The SSQ consisted of 49 questions within three subdomains (14 questions on speech hearing, 17 on spatial hearing, and 18 on qualities of hearing) (21). SSQ scores were reported as raw values, out of a total score of 10. In SSQ, the closer the score to 10, the lesser the difficulty noted by the patient. In a prior study in adults, the average scores on the SSQ subscales ranged from 7.86 to 7.47, with an upper range of 8.11–8.64 in normal hearing adults (22). Therefore, an SSQ score of 8 was considered the lowest possible adequate score in our patients.

Rehabilitation Methodology

Recipients and families were counseled on the importance of focused and consistent auditory rehabilitation exercises after implantation and given home-based activity recommendations. Children were encouraged to participate in auditory therapy streamed directly to their CI processor via smartphone, tablet, and/or Bluetooth accessory with parental assistance in order to isolate the implanted ear. Families were given options for assistance with setting up accessory equipment. Recommended activities included applications and programs targeting sound discrimination through auditory comprehension to build upon auditory skills in the newly implanted ear. Children and families were encouraged to participate in 30–60 minutes of focused auditory rehabilitation tasks five times per week. Families were also encouraged to schedule a formal auditory-based therapy appointment postactivation.

All patients in the study cohort attended auditory-based therapy sessions with a Listening and Spoken Language certified Auditory–Verbal Therapist. Isolating the nonimplanted ear was achieved using a “plug-and-muff method” with an ear insert or pediatric-sized ear plug and a child-sized ear muff. While providing therapy through direct connect to the CI ear is optimal for complete isolation of the nonimplant ear, as plug-and-muff does not completely attenuate the nonimplant ear (23,24), direct connect was not possible in all cases due to the unavailability of appropriate equipment for the therapist. Auditory training focused on listening practice in the CI-only condition using an auditory hoop to eliminate speechreading/visual cues. Auditory activities included Ling Six Sounds, Early Speech Perception (ESP) (subtest 1 [Pattern Perception] and 3 [Word Recognition]), and word discrimination contrasts (e.g., “ogre” versus “odor”). For select patients, auditory connected discourse tracking in which word per minute scores could be calculated was also performed. Families were encouraged to continue these activities at home, in addition to the emphasis on streaming, to maximize the auditory growth of the implanted ear.

Statistical Analysis

Demographic and audiometric characteristics were summarized descriptively. Categorical factors were described with frequencies and percentages, and continuous variables were summarized with means and standard deviations (SD) or medians and interquartile ranges (IQR). Each patient’s score on SSQ, BABY BIO in quiet, CNC, and WIPI is depicted visually in Figures 1–4. Statistical analyses were performed in R software (version 3.5, Boston, MA) with p < 0.05 considered significant.

FIG. 1.

Individual patient scores for Speech, Spatial and Qualities of Hearing Scale (SSQ) following cochlear implantation (n = 9). Numbers in white text denote postimplantation testing in months.

FIG. 4.

Individual patient scores for WIPI following cochlear implantation (n = 13). Numbers in white text denote postimplantation testing in months. WIPI indicates word intelligibility by picture identification.

RESULTS

Study Population

In total, 38 patients (24 females, 14 males) with UHL were included. Mean age at CI was 6.9 years (SD ± 3.2; range, 1–17), and mean duration of hearing loss prior to implantation was 5.0 years (SD ± 2.9; range, 1–12) (Table 1). There were 20 patients (53%) who failed their newborn hearing screen but were diagnosed with hearing loss only after repeat screening, either at school or at the pediatrician’s office. Hearing loss was severe or profound in 35 patients (92%) at the time of implantation. The remaining 3 patients (7.9%) had residual low-frequency hearing loss but poor thresholds in remaining frequencies with poor word discrimination. Etiology of hearing loss was due to inner ear anatomic anomaly (n = 8, 21.1%), cytomegalovirus (CMV) (n = 2, 5.3%), temporal bone fracture (n = 1, 2.6%), and unknown/idiopathic (n = 26, 68.4%). Among our cohort, no children had known cognitive deficits. In total, 27 patients (71.1%) were daily users, whereas 11 patients (28.9%) used their CI <8 hours per day. Mean duration of device use since implantation was 14.7 months (SD ± 15.0).

TABLE 1.

Summary of individual patient characteristics for study cohort (n = 38)

Patient No.	Sex	Etiology of Hearing Loss	Imaging Findings	Duration of Hearing Loss, in Years	Age at CI, in Years	Cochlear Implant Device	Data Log (Hours/Day)	Duration of Device Use, in Months
1	F	Unknown	Normal	7	7	CI632	11.4	11
2	F	Unknown; birth history notable for emergency C-section for hypoxic encephalopathy	Normal	7	8	CI632	8.0	3
3	F	Inner ear anatomic anomaly	IP2	7	8	CI632	11.5	6
4	F	Unknown	Normal	8	8	CI632	9.7	11
5	F	CMV	Periventricular intensity (CMV)	8	8	CI632	6.1	19
6	F	Inner ear anatomic anomaly	IP2	8	8	CI632	11.4	9
7	M	Inner ear anatomic anomaly	Dysmorphic cochlea	8	8	CI622	11.4	4
8	M	Inner ear anatomic anomaly	Absent SCC, dysmorphic vestibule	10	10	CI632	9.3	11
9	F	Inner ear anatomic anomaly	EVA	11	11	CI632	0.5	16
10	F	Unknown	Normal	12	12	CI632	8.9	15
11	M	Unknown	Normal	8	13	Nucleus 624	6.6	24
12	M	Unknown	Normal	7	17	CI522	4.2	6
13	F	Unknown	Normal	4	1	Nucleus 632	8.6	24
14	F	Unknown	Normal	2	2	AB	8.0	40
15	F	Unknown	Normal	3	3	AB MID SCALA	6.5	60
16	F	Unknown	Normal	3	3	Nucleus 632	0.2	12
17	M	Inner ear anatomic anomaly	EVA	4	4	CI632	8.4	19
18	F	Unknown	Normal	2	4	CI512	9.4	11
19	M	CMV	Periventricular intensity (CMV)	4	4	AB	8.0	30
20	F	Unknown	Normal	1	5	CI632	10.8	11
21	M	Inner ear anatomic anomaly	Dysmorphic cochlea	5	5	CI512	8.5	28
22	M	Unknown	Normal	3	5	Nucleus 632	10.2	6
23	M	Unknown	Normal	3	5	Nucleus 632	10.5	6
24	M	Unknown	Normal	5	5	Med EL Synchrony 2 Flex 28	9.3	6
25	F	Unknown	Normal	5	5	Med EL Synchrony 2 Flex 28	10.7	3
26	F	Unknown	Normal	5	5	Nucleus 632	11.2	6
27	F	Unknown	Normal	5	5	Med EL Synchrony 2 Flex 28	11.5	3
28	M	Unknown	Normal	5	5	Cochlear profile 622	8.0	20
29	M	Unknown	Normal	6	6	Nucleus 632	9.3	6
30	F	Unknown	Normal	3	6	Nucleus 512	9.2	72
31	F	Unknown	Normal	2	6	Med EL Synchrony 2 Flex 28	7.4	6
32	F	Unknown	Normal	2	7	CI632	10.5	6
33	F	Unknown	Normal	5	8	Nucleus 632	6.0	12
34	F	Inner ear anatomic anomaly	Dysmorphic cochlea	4	8	Nucleus 632	2.2	9
35	M	Temporal bone fracture	Absent SCC	1	8	Nucleus 632	11.0	3
36	F	Unknown	Normal	4	10	MEDEL	8.0	5
37	F	Unknown	Normal	1	10	CI632	1.7	6
38	M	Inner ear anatomic anomaly	EVA	2	11	Nucleus 632	4.0	12

CI indicates cochlear implantation; CMV, cytomegalovirus; EVA, enlarged vestibular aqueduct; F, female; IP2, incomplete partition type 2; M, male; SCC, semicircular canal.

Imaging Anomalies

Imaging abnormalities were present in 12 patients (31.6%), which included incomplete partition type II (n = 5), enlarged vestibular aqueduct (n = 3), absent semicircular canal (n = 2), and periventricular intensities consistent with cytomegalovirus infection (n = 2). Of these 12 patients with imaging abnormalities, 8 (66.7%) were daily users, whereas 4 (33.3%) were limited users, with usage <8 hours per day.

Outcomes and Questionnaire Results

Supplemental Table 1, http://links.lww.com/MAO/B856, summarizes the auditory testing outcomes. SSQ score was available for 9 patients (24%), at a time range of 1–16 months after CI. Average SSQ was 7.9 points (median, 8.1; IQR, 7.8–8.6) (Fig. 1). BABY BIO in quiet score was available for 24 patients (63%), at 3–72 months post-CI. Average BABY BIO in quiet was 68% (median, 82%; IQR, 51–93%) (Fig. 2). CNC score was available for 20 patients (53%) at 1–72 months post-CI. Average CNC was 39% (median, 46%; IQR, 11–65%) (Fig. 3). WIPI was available for 13 patients (34%) at 3–28 months post-CI. Average WIPI was 53% (median, 50%; IQR, 36–60%) (Fig. 4). Scores greater than 50% were achieved by 40% of patients on CNC. Of the 4 children with imaging abnormalities who were limited users, BABY BIO in quiet scores ranged from 52% to 100%, whereas CNC scores ranged from 28% to 72%.

FIG. 2.

Individual patient scores for BABY BIO (quiet) following cochlear implantation (n = 24). Numbers in white text denote postimplantation testing in months. BABY BIO indicates pediatric AzBio.

FIG. 3.

Individual patient scores for CNC following cochlear implantation (n = 20). Numbers in white text denote postimplantation testing in months. CNC indicates consonant–nucleus–consonant.

Duration of Hearing Loss and Age at Implantation

There were no significant associations between duration of hearing loss and any of the auditory testing scores (p > 0.05) (Fig. 5). Duration of UHL was positively correlated with SSQ (ρ = 0.78, p = 0.014) among 9 patients tested. Age at implantation was not associated with SSQ or any of the auditory testing outcomes.

FIG. 5.

Spearman’s correlation coefficient assessed linear associations between age at cochlear implantation and auditory outcomes (top row), and between duration of hearing loss and auditory outcomes (bottom row).

DISCUSSION

CI has been increasingly used to restore access to binaural sound in children with UHL. Children and adolescents with SSD have been shown to consistently use their CI in a variety of environments (25,26). Binaural hearing, even when the hearing is bimodal with a CI in one ear and acoustic hearing in the unaffected ear, allows for binaural summation, squelch, and restoration of the head shadow effect. Several prior studies have suggested that duration of hearing loss and older age at implantation are associated with poorer outcomes in patients who undergo CI for SSD (1,5,27,28). Conversely, other reports demonstrate satisfactory outcomes even with longer durations of hearing loss and older age at implantation (29,30). Due to these equivocal results, this present case series contributes to the literature on outcomes in children with UHL in a larger, multi-institutional cohort. Overall, many children with UHL demonstrated satisfactory speech perception scores and all children perceived their hearing abilities to fall within the top 50% of the SSQ range (0 to 10) after CI. Furthermore, there were no associations between duration of hearing loss or age at implantation with auditory outcomes.

Prior studies on CI in pediatric UHL have reached divergent conclusions regarding age at which poorer outcomes are observed (27,30). Rauch et al. (27) reported that among 11 children with congenital SSD, improvement in speech discrimination and subjective benefit as measured by SSQ was highest for children under 3 years at the time of implantation, whereas children 5 years and older did not demonstrate as much improvement. When comparing 13 postlingually deafened, 3 peri-lingually deafened, and 4 congenitally deafened children, Arndt et al. (28) concluded that longer durations of hearing loss were associated with worse auditory outcomes after CI. By contrast, among 21 children with congenital SSD, implanted between 10 months and 11.3 years, Thomas et al. (30) showed improvements on the SSQ for all children with no differences between those implanted at <6 and >6 years old. Hearing loss duration <7 years has been associated with improved auditory and patient-reported outcomes (5). Overall, auditory deprivation during periods of high neural plasticity can be highly variable between individuals, ranging from as young as 3.5 years and up to 7 years of age, which may be associated with delayed auditory cortex maturation, poorer neurocognition, and performance with CI (31,32).

Among this cohort, the mean age at implantation (6.9 years) and the mean duration of hearing loss (5.0 years) are both higher than most previous studies (25,27,29,30,33,34). Patients with longer duration of hearing loss had variable auditory outcomes but had SSQ with scores ranging from 5.9 to 9.4. The mean SSQ score in our cohort (7.9) was similar to previous reports in the literature. In a prospective clinical trial of 20 children with moderate-to-profound UHL, SSQ improved from 5.2 to 7.4 (33). Beck et al. (35) showed that in 10 children with SSD, the mean postoperative SSQ score was 8.8 among implanted children and 7.1 as reported by their adult caregivers. Our findings showed most children (7/9) had a score of nearly 8 or more following CI.

In addition to SSQ, auditory outcomes were assessed using three different, age-appropriate speech perception measures. Variable outcomes between patients and within patients were observed for these outcome measures, which may reflect the variability in test design. The BABY BIO test is performed by presenting 20 spoken sentences and asking the patient to repeat back the entire sentence. The limitation of the BABY BIO test is that children may be able to fill in words they did not hear using contextual cues based on sentence structure, potentially leading to artifactually elevated scores. The WIPI test was designed for pediatric patients and uses monosyllabic words chosen from children’s books. The patient is asked to point to one of the six given pictures representing the word they heard. In contrast to these two tests, the CNC monosyllabic word test measures word recognition by presenting 50 monosyllabic words that reflect the frequency of phonemes in the English language, and the patient must say the word back (36). The CNC word test is an open-set test, which contributes to its increased difficulty when compared to the WIPI which is closed-set test. The probability of a patient guessing the correct word in WIPI even if not correctly perceived during stimulus presentation is approximately 20%. Thus, patients are likely to achieve higher scores on BABY BIO and WIPI than on CNC. For example, Patient 1, a patient with prolonged hearing loss implanted at 7 years old who logged an average of 11.4 hours/day, had a best score of 50% on BABY BIO and 84% on WIPI at 11 months postactivation and 8% on CNC at 18 months postactivation.

CNC monosyllabic word scores were 50% or higher in 8/20 patients (40%) in our cohort, 2 (25.0%) of whom had ≥7 years of hearing loss. Brown et al. (33) reported that approximately half of patients scored ≥50% on CNC at 9 months after CI. In their cohort, however, the median duration of hearing loss was only 2.4 years, and there were no patients who had a duration of hearing loss of 7 years or greater. Zeitler et al. (34) studied nine children with SSD, with a median age at implantation of 8.9 years and median duration of hearing loss of 2.9 years. There were only two patients who had a prolonged duration of hearing loss of 7 years or longer. Among the overall study cohort, 3/4 (75%) patients scored ≥50% on CNC (34).

Patients who tested poorly on the CNC word test tended to achieve higher scores on sentence testing on BABY BIO or WIPI word testing. In BABY BIO, 80% is considered a ceiling at which more difficult testing is recommended as per the Pediatric Minimum Speech Test Battery (37). Even using this stringent criterion as a satisfactory outcome, BABY BIO in quiet scores were ≥80% in half the children in our cohort. Among 8 children with severe-to-profound UHL, Deep et al. (29) showed that the mean word recognition score on BABY BIO in noise was 56% postimplantation, which was improved from baseline. Average BABY BIO in this study was slightly higher at 68%, although the studies are unable to be directly compared given differences in masked sentence recognition and sentence recognition in quiet. Lastly, in this study, average WIPI score was 53% postimplantation. To our knowledge, the WIPI word test in children who have undergone CI for SSD has not been previously reported and therefore it is unclear on expected average outcomes with this test. Furthermore, masking has been shown to produce worse word recognition when compared to other methods of isolation, and thus scores may be under-representative of performance in this study cohort (38). Therefore, the outcomes seen on these measures suggest that there can be satisfactory auditory testing scores following CI in these children, albeit in less challenging testing conditions as in CNC monosyllabic word test.

Even when the auditory outcomes were not considered satisfactory on these testing measures, children with prolonged durations of hearing loss continued to be high users, suggesting perceived quality of hearing despite lack of high testing scores. Indeed, duration of hearing loss was positively associated with SSQ. Although it is difficult to derive decisive conclusions based on the small number of patients with SSQ outcomes measured, the positive association with SSQ is congruent with the findings of high device use even with prolonged duration of hearing loss. This may be due to the attainment of sound awareness, binaural hearing benefits, listening efforts, the ability to localize sounds, and other benefits even in setting of poor comprehension. Therefore, auditory outcomes may not simply be enough to predict device use or perceived quality of hearing. Brown et al. (22) showed improvement in sound localization by 26° as early as 9 months of CI use. Moreover, there may be subjective benefits with CI use in cases of UHL that cannot be easily measured but are appreciated by the CI user nonetheless. As an example, an adult study showed improvement in listening effort with CI in UHL (39). The current study did not evaluate the importance of these qualitative benefits such as sound awareness, sound localization, listening efforts, and others. Further studies should be conducted to understand the impact of these variables on device use and patient satisfaction.

In our study, recipients who were compliant with at-home aural rehabilitation recommendations and used their devices consistently generally had better speech perception auditory outcomes. In order to successfully stream auditory training activities, the recipient and/or family needed to complete initial setup of the processor to a smartphone, tablet, and/or accessory device and re-establish connection prior to each streaming session. Setup was variably challenging for families, suggesting the potential disparities due to “technological savviness” on postoperative CI outcomes. Home-based intervention requires motivation by the recipient and a commitment to a collaborative partnership between parent (s) and recipient to consistently participate in auditory training to maximize CI performance. While these children often meet basic speech and language milestones, they may experience more subtle difficulties requiring caregivers to receive additional counseling on the importance of focused auditory training tasks. Pediatric recipients need to be motivated to remain an active participant in auditory training activities. This can be done using a variety of fun and interactive games to target auditory skills of all levels, any of which are accessible via smartphone or tablet for direct streaming. Existence of these interactive games directed toward younger, preliterate children were more limited than for older children. This highlights the need for more accessible auditory training applications and programs targeting all ages and auditory skill levels for home-based training. We also recommend more comprehesive pre- and postactivation outcome measurements in the areas of localization, speech-in-noise, and quality of life assessments, acknowledging the additional time and space requirements (24).

Limitations

Although this study’s strengths lie in the multi-institutional representation and validated scores, this study is not without limitations. Compliance with therapy visits and adherence to recommendations for home can indeed impact outcomes. This study’s aim was to evaluate patient-related preoperative factors on outcomes, specifically duration of hearing loss and age at implantation. The rate of follow-up for therapy, compliance with rehabilitation, and adherence to home recommendations were variable, which may reflect differences in many factors, including patient and family motivation and socioeconomic factors. The sample size of 38 children, although larger than other studies, is a small series with variable socioeconomic backgrounds, rate of adherence to work at home, and audiological history. Socioeconomic variables, such as poverty level and maternal education, are known to impact cognitive function, speech/language development, and development (6–8). The study is not statistically powered to correct for these variables, to compare subgroups, nor to establish recommendations on how to treat these patients. Future studies are needed to truly understand the impact of postoperative factors, including consistent therapy and device use, interventions, consistent isolated auditory training after implantation, and others. There was limited baseline speech testing and SSQ data on the implanted and contralateral ear to serve as comparison groups and should be included in future prospective studies. The outcomes measured in this study focused solely on open-set speech perception in the implanted ear and perception of hearing disabilities using SSQ. Future studies need to evaluate development of binaural skills after CI, including localization, binaural speech perception, and hearing in background noise. Despite these limitations, we share our institutional best practices and add to the limited existing literature on children with UHL undergoing CI.

CONCLUSION

This multi-institutional series demonstrates that children with UHL can achieve satisfactory scores in hearing quality on SSQ and auditory tests after cochlear implantation. There were no associations between duration of hearing loss or age at implantation and auditory outcomes. Daily full-time CI users did not necessarily have the best performance on auditory testing, suggesting that CI may provide advantages in quality of hearing that may not be measured with speech perception tests. Multiple variables may impact auditory outcomes, including motivation, family support, access to technology, and consistent isolated auditory training postactivation, and should be taken into consideration in addition to age and duration of UHL in determination of CI candidacy. Future studies with larger sample sizes are needed to further evaluate the optimal timing of CI in children with UHL.