Bilateral Profound Sensorineural Hearing Loss Research Articles

Identification of novel CDH23 variants linked to hearing loss in a Chinese family: A case report.

Deafness is associated with both environmental and genetic factors, with hereditary deafness often caused by mutations in deafness-related genes. Identifying and analyzing deafness-related genes will aid in early diagnosis and pave the way for treating inherited deafness through gene therapy in the future. A 15-month-old girl underwent audiological examination at the outpatient clinic of the hospital due to hearing loss and her brother was diagnosed with profound bilateral sensorineural hearing loss at the age of 3. The diagnosis was determined as extremely severe sensorineural hearing loss caused by genetic factors. Clinical data of the patient were collected, and peripheral blood samples were obtained from both the patient and her family members for DNA extraction and sequencing. By utilizing targeted capture next-generation sequencing to further screen for deafness-related genes, 2 novel variants in CDH23 were identified as the causative factors for the patient's deafness. This study identified 2 novel heterozygous mutations in a Chinese family. Both the proband and her sibling have non-syndromic hearing loss (NSHL) and carry distinct heterozygous mutations of cadherin-like 23 (CDH23). One mutation, CDH23:c.2651 A>G, originated from their mother and paternal family, affecting the exon23 domain of CDH23. The other mutation, CDH23:c.2113 G>T, was inherited from their paternal grandmother, impacting the exon19 domain of CDH23. These 2 novel mutations likely cause NSHL by affecting protein function. This finding suggests that identifying 2 novel mutations in CDH23 contributes to the genetic basis of NSHL.

Dynamic functional network connectivity in children with profound bilateral congenital sensorineural hearing loss.

Functional magnetic resonance imaging (fMRI) studies have revealed extensive functional reorganization in patients with sensorineural hearing loss (SNHL). However, almost no study focuses on the dynamic functional connectivity after hearing loss. This study aimed to investigate dynamic functional connectivity changes in children with profound bilateral congenital SNHL under the age of 3years. Thirty-two children with profound bilateral congenital SNHL and 24 children with normal hearing were recruited for the present study. Independent component analysis identified 18 independent components composing five resting-state networks. A sliding window approach was used to acquire dynamic functional matrices. Three states were identified using the k-means algorithm. Then, the differences in temporal properties and the variance of network efficiency between groups were compared. The children with SNHL showed longer mean dwell time and decreased functional connectivity between the auditory network and sensorimotor network in state 3 (P < 0.05), which was characterized by relatively stronger functional connectivity between high-order resting-state networks and motion and perception networks. There was no difference in the variance of network efficiency. These results indicated the functional reorganization due to hearing loss. This study also provided new perspectives for understanding the state-dependent connectivity patterns in children with SNHL.

A novel case of Takenouchi-Kosaki syndrome: Focus on hearing and language rehabilitation

Abstract Takenouchi-Kosaki syndrome (TKS) is a rare congenital condition, caused by a mutation in the cell division cycle 42 gene. This gene typo impacts various physiological processes, including hearing, hematopoiesis, immunologic functioning, and neurodevelopment. Despite the high prevalence of hearing impairment in TKS, existing literature has concentrated primarily on pharmacological treatments for hematoimmunologic diseases. This case report presents a novel case of TKS, highlighting the importance of audiological assessment and rehabilitating interventions in children with TKS. We discuss the case of a prematurely born boy who was diagnosed with TKS and who presented with profound bilateral sensorineural hearing loss and associated developmental delays. Following comprehensive audiological evaluation and intervention – including hearing aids, sign language, and alternative augmentative communication systems – a multidisciplinary approach was adopted to enhance his communicative abilities. From this study, it emerges the increasing need for tailored rehabilitation strategies for TKS patients to improve communication skills and overall quality of life. Further researches are needed to develop standardized protocols for assessment and treatment in patients with TKS.

Experiencia clínica con el implante coclear Nurotron™ en una población postlingual hispanohablante: seguridad clínica y resultados audiólogicos

Objectiveto assess clinical safety and postoperative audiological outcomes in postlingual deafness Spanish speaking patients, who underwent surgery with Nurotron™ cochlear implant. Material and MethodsRetrospective descriptive case series study. We performed follow-up of complications and audiological measurements before and after cochlear implantation. Patients with bilateral severe to profound sensorineural hearing loss or patients with unilateral deafness with/without tinnitus were included. Repeated-measures within-subjects for assess pure tone thresholds and speech performance (bilingual test) with a detailed monitoring to establish security or adverse effects were performed. Analysis of variance tests, repetitive measures, were used for statistical analysis. Results31 patients were included, 17 (54.8%) men and 14 (45.2%) women. Mean age at the time of surgery was 49.82 ± 18.8 years. The mean follow-up of the group was 31.56 ± 9.57 months (minimum = 19.6 months and maximum = 52.50months). As major complication one patient (3.23%) had a hard failure that required removal and re-implantation. 25.8% of the patients presented minor complications, the most frequent being vertigo/unsteadiness in 22.6%.The mean of language discrimination (free field at 65 dB SPL) was 62.19% ± 16.66; being 69.82% ± 7.35 in the group of severe to profound bilateral sensorineural hearing loss. A statistically significant reduction was observed in patients with tinnitus, assessed using the visual analog scale, preoperative = 7.2 ± 1,6 vs postoperative (18 months postoperative) = 1.7 ± 1.3 (p < 0.001). ConclusionsThe Nurotron™ cochlear implant shows satisfactory audiological results, in accordance with what has been reported in the literature. Minor complications were similar to previous studies, but the percentage of hard failure should continue to be observed, which was higher than other reports with comparable follow-up.

Management of a Case of Bilateral Severe External Auditory Canal Stenosis, Bilateral Cholesteatoma Causing Right-sided Inner Ear Erosion, and Bilateral Profound Sensorineural Hearing Loss

Bilateral simultaneous external auditory canal (EAC) stenosis with bilateral cholesteatoma is a rare presentation. We present a case report of surgical and audiological management of an elderly male who presented with bilateral EAC stenosis, bilateral cholesteatoma, right-sided inner ear erosion, and bilateral profound sensorineural hearing loss.

Clinical experience with the Nurotron™ cochlear implant in a Spanish-speaking postlingual population: Clinical safety and audiological results

Objectiveto assess clinical safety and postoperative audiological outcomes in postlingual deafness Spanish speaking patients, who underwent surgery with Nurotron™ cochlear implant. Material and methodsRetrospective descriptive case series study. We performed follow-up of complications and audiological measurements before and after cochlear implantation. Patients with bilateral severe to profound sensorineural hearing loss or patients with unilateral deafness with/without tinnitus were included. Repeated-measures within-subjects for assess pure tone thresholds and speech performance (bilingual test) with a detailed monitoring to establish security or adverse effects were performed. Analysis of variance tests, repetitive measures, were used for statistical analysis. Results31 patients were included, 17 (54.8%) men and 14 (45.2%) women. Mean age at the time of surgery was 49.82 ± 18.8 years. The mean follow-up of the group was 31.56 ± 9.57 months (minimum = 19.6 months and maximum = 52.50 months). As major complication one patient (3.23%) had a hard failure that required removal and re-implantation. 25.8% of the patients presented minor complications, the most frequent being vertigo/unsteadiness in 22.6%.The mean of language discrimination (free field at 65 dB SPL) was 62.19% ± 16.66; being 69.82% ± 7.35 in the group of severe to profound bilateral sensorineural hearing loss. A statistically significant reduction was observed in patients with tinnitus, assessed using the visual analogue scale, preoperative = 7.2 ± 1,6 vs postoperative (18months postoperative) = 1.7 ± 1.3 (p < .001). ConclusionsThe Nurotron™ cochlear implant shows satisfactory audiological results, in accordance with what has been reported in the literature. Minor complications were similar to previous studies, but the percentage of hard failure should continue to be observed, which was higher than other reports with comparable follow-up.

Возможности трехмерной (3D) визуализации внутреннего уха при планировании хирургического этапа кохлеарной имплантации

Cochlear implantation is a highly effective surgical intervention in the treatment of patients with bilateral profound sensorineural hearing loss. Important methods of visualization diagnostics, preparation for surgery, and further prediction of the results of auditory-speech rehabilitation are computed tomography and magnetic resonance imaging. However, in the presence of inner ear malformation, cochlear ossification at any length and localization as well as in the presence of retrocochlear pathology, even with these diagnostic methods, it is not always possible to accurately assess the configuration of the cochlea, the length of the spiral canal, and the state of the auditory nerve in the internal auditory canal. Based on the results of this study, a reliable method of visualizing these anatomical structures using computed tomography and magnetic resonance imaging is studied and described. This method makes possible to detect and determine the localization and extent of ossification in the scala timpani, the shape of the cochlear basal coil, to measure the length of the cochlear spiral canal, and to assess the condition of the auditory nerve in the internal auditory canal, which is of great clinical importance for surgical planning, selecting the optimal electrode, and predicting further results of auditory-verbal rehabilitation.

Late-onset of Labyrinthine Dysfunction in Chronic Brucella-induced Encephalitis

Brucellosis, caused by Brucella, dominates in the Middle East. Acute or chronic brucellosis can involve any organ system, and the involvement of the central nervous system leads to encephalitis, called neurobrucellosis (NB). We report a rare case from north India where a variant of Brucella caused NB led to progressive labyrinthine dysfunction; who developed vertigo, disequilibrium, and gradual progressive sensorineural (SN) hearing loss. Audiological tests pure-tone audiometry (PTA), otoacoustic emissions (OAE), stapedial muscle reflexes, auditory evoked brainstem responses (ABR), and vestibular evoked myogenic potentials (VEMPs) were conducted on the patients. PTA showed a bilateral profound SN hearing loss, an absent OAE, and ABR suggestive of cochlear dysfunction. The cervical and ocular VEMP showed delayed n1 and p1 latencies, suggesting superior and inferior nerve branch involvement. Vertigo or disequilibrium and SN hearing loss can be the late-onset manifestations of labyrinthine dysfunction in chronic Brucella-induced encephalitis.

Postmeningitic pediatric hearing loss from non-type b Haemophilus influenzae

BackgroundPostmeningitic hearing loss from Haemophilus influenzae (H. influenzae) is increasingly due to encapsulated serotypes other than type b (Hib) and nontypeable strains (collectively, nHiB H. influenzae). Pediatric hearing loss after nHib H. influenzae meningitis remains poorly described. MethodsRetrospecive case series of nHiB H. influenzae meningitis cases identified from a microbiologic database at Children's Hospital Colorado from 2000 to 2020. Literature regarding nHiB H. influenzae and H. influenzae postmeningitic hearing loss was also reviewed. ResultsEleven cases of nHib H. influenzae meningitis (median age 15.9 months) were identified due to serotype f (36 %), serotype a (27 %), and nontypable strains (36 %). Seven (64 %) patients were male, 55 % were white and 18 % were Hispanic or Latino. Hearing loss was initially identified in 4 children (40 %), with two patients with moderate conductive hearing loss (CHL) and one child with unilateral moderate sensorineural (SNHL) hearing loss patients recovering normal hearing. One patient with bilateral profound sensorineural hearing loss and associated labyrinthitis ossificans required cochlear implantation. All children (4) with identified hearing loss were noted to have additional intracranial sequelae, which included empyema (2), sinus thrombosis (2), and seizures (2). Of patients receiving steroids, 25 % had hearing loss on initial testing, compared to 66 % of those who did not receive steroids. ConclusionsnHib H. influenzae can cause both transient and permanent postmeningitic hearing loss. Steroids may offer otoprotection in nHib H. influenzae meningitis similar to Hib meningitis. Given the limited literature, further study is needed to better characterize hearing outcomes after nHib H. influenzae meningitis.

Idiopathic sequential bilateral profound sudden sensorineural hearing loss occurring 4 years after unilateral presentation

Sudden sensorineural hearing loss is defined as hearing loss of 30db or more at least 3 consecutive audiometric frequencies occurring within 72 hours period or less. Unilateral presentation of sudden sensorineural hearing loss is common, however bilateral sequential presentation of this disease is very rare. Clinically we couldn’t anticipate the occurrence of sequential bilateral sudden sensorineural hearing loss at the first time. This bilateral sudden sensorineural hearing loss will affect the quality of life of patient. So, we report a case of 60 years old female patient with profound bilateral sudden sensorineural hearing loss with time interval of 4 years between involvement of both ears. Even though high dose steroid administered intravenously and intratympanic the patient’s hearing was not restored and eventually require hearing aids. The purpose of presenting this article is that sequential profound bilateral sensorineural hearing loss may present without any warning sign, response to treatment is very poor and the rarity of this condition.

Round Window Niche Veil is Visible on High-Resolution Computed Tomography and a Predictor of Local Drug Efficacy to Inner Ear.

To determine the morphologies and effect of the round window niche veil (RWNV) on local drug delivery efficacy and develop diagnostic criteria on high-resolution computed tomography (HRCT). Patients diagnosed with otosclerosis, bilateral profound sensorineural hearing loss or vestibular schwannoma were enrolled from 2019 to 2022, receiving temporal bone HRCT scanning, and anatomic variations of RWMV were summarized intraoperative. For patients with vestibular schwannoma, 1 mL of dexamethasone solution (4 mg/mL) was administered via facial recess during operation, and samples of perilymph were collected to analyze. The diagnostic criteria of RWNV on HRCT were developed and verified. A total of 85 patients were enrolled. RWNV was observed in 54 cases intraoperatively with an incidence of 63.5% (95% CI, 52.9%-73.0%). The median perilymph concentrations were 4.86-fold higher in the group without RWNV than with RWNV (p < 0.0001). RWNV could be visualized on HRCT with a window width of 3500-4500 HU and a window level of 300-500 HU. The characteristic features were as follows: (1) a thin soft tissue shadow could be seen at the entrance of the round window niche (RWN); (2) it was visible in at least 2 consecutive layers along the upper margin of RWN from top to bottom; (3) it was discontinuous with the adjacent bone margin. The sensitivity and specificity of the diagnostic criteria were 77.8% and 93.6%, respectively. RWNV could reduce local dexamethasone diffusion efficacy to the inner ear, which could be diagnosed on HRCT and used as a predictor of local drug delivery efficacy to the inner ear. 3 Laryngoscope, 134:1396-1402, 2024.

A Case Report of Riboflavin Treatment and Cochlear Implants in a 4-Year-Old Girl with Progressive Hearing Loss and Delayed Speech Development: Brown-Vialetto-Van Laere Syndrome.

BACKGROUND Brown-Vialetto-Van Laere (BVVL) syndrome is a rare autosomal recessive disorder caused by mutations in intestinal riboflavin transporter genes, resulting in a motor neuron disorder of childhood, which can be associated with sensorineural deafness. This report describes a 4-year-old Polish girl with progressive hearing loss and delayed speech development diagnosed with Brown-Vialetto-Van Laere syndrome who was treated with riboflavin (vitamin B2) and cochlear implants. CASE REPORT The case report concerns a girl from Poland who, at the age of 2 years 10 months, developed progressive atypical neurological symptoms of unknown etiology: ataxia of the upper and lower limbs, gait abnormalities, generalized muscle weakness, visual and hearing problems, and regression of speech development. A karyotype study (whole-exome sequencing) revealed alterations within SLC52A2, leading to the diagnosis of Brown-Vialetto-Van Laere syndrome and initiation of high-dose riboflavin treatment. As a 4-year-old child, she presented to the Institute of Physiology and Pathology of Hearing-World Hearing Center in Poland with progressive hearing loss and speech regression. Hearing tests revealed bilateral profound sensorineural hearing loss with auditory neuropathy. Surgical treatment was applied in the form of bilateral cochlear implantation. CONCLUSIONS This report shows the importance of genetic testing in infants who present with atypical symptoms or signs. In this case, the diagnosis of Brown-Vialetto-Van Laere syndrome resulted in timely correction of the genetic riboflavin (vitamin B2) deficiency and improved hearing following the use of cochlear implants.

Age and Incidence of Cochlear Implantation in the Pediatric Population With Congenital Bilateral Profound Hearing Loss.

The current study characterizes age and incidence of cochlear implantation among qualifying children with congenital bilateral profound hearing loss in the U.S. Deidentified cochlear implantation data were acquired from prospectively collected patient registries from two cochlear implant (CI) manufacturers (Cochlear Americas and Advanced Bionics). Children <36 months old were assumed to have congenital bilateral profound sensorineural hearing loss. U.S. CI centers. Children <36 months old who received CIs. Cochlear implantation. Age at implantation and incidence. A total of 4,236 children <36 months old underwent cochlear implantation from 2015 to 2019. The median age at implantation was 16 months (interquartile range, 12-24 mo) and did not change significantly during the 5-year study period ( p = 0.09). Patients residing closer to CI centers ( p = 0.03) and treated at higher-volume centers ( p = 0.008) underwent implantation at a younger age. Bilateral simultaneous implantation increased from 38% to 53% of CI surgeries in 2015 and 2019, respectively. Children who received bilateral simultaneous CIs were younger compared with those receiving unilateral or bilateral sequential CIs (median, 14 versus 18 mo; p < 0.001). The incidence of cochlear implantation increased from 7,648 per 100,000 person-years in 2015 to 9,344 in 2019 ( p < 0.001). Although the incidence of pediatric CI recipients and the frequency of bilateral simultaneous implantation increased over the study period, age at implantation did not change significantly and far exceeded current Food and Drug Administration (9 mo) and American Academy of Otolaryngology and Head and Neck Surgery position statement (6-12 mo) guidelines.

Novel cochlear implant assessment tool: Comparative analysis of children and adults.

To analyse the results of children and adults with cochlear implants (CIs) in pure tone audiometry (PTA) and speech perception tests. Tests were performed in two ways: using loudspeakers in the sound booth (SB) and with direct audio input (DAI) employing the Cochlear Latin America BOX (CLABOX). Fifty individuals (33 adults and 17 children) participated in the study, including children aged between 8 and 13 years; of these, 15 users had bilateral CIs, 35 had unilateral CIs, and all had severe to profound bilateral sensorineural hearing loss. All participants were evaluated in the SB with loudspeakers and the CLABOX with DAI. The following evaluations were conducted: PTA, speech recognition tests with the hearing in noise test (HINT). The results for PTA and HINT conducted in SB and with CLABOX presented no significant difference between children and adults. The CLABOX tool presents a new possible method to evaluate PTA and speech recognition tests in adults and children, with results comparable to the conventional evaluation in the SB.

Exposure to emotions and postural stability in deaf youth

IntroductionThe population of deaf people is a heterogeneous group. Understanding the significant variables that affect motor, socio-emotional and cognitive development sets the direction and quality for subsequent developmental stages and provides the opportunity to select appropriate compensatory methods for deaf individuals.AimThe aim of the study was to verify the visual effect of the emotions of joy and anger on one of the dimensions of eye-hand coordination, i.e. postural stability among deaf and hearing youth.Material and methodsStudy subjects: 120 teenagers aged 13–17 years. The test group comprised 60 subjects with profound bilateral sensorineural hearing loss, while the control group comprised 60 hearing junior high school students. The study used a computerised stabilometric platform and photographs sourced from an affective image database Montreal Set of Facial Displays of Emotion.Results and discussionIn deaf youth, a switch in the stability of the body occurs, as compared to hearing youth. The results obtained indicate the need for the activation of cognitive, emotional and motor resources of deaf people with an area of multiple modalities taken into account.ConclusionsHuman development should be regarded as a continual process in relation to compensatory capacity.

Results of cochlear implant surgery in patients with auditory neuropathy.

The primary aim of this study was to analyze the benefit of cochlear implants for patients with auditory neuropathy. The secondary aim was to identify risk factors for auditory neuropathy. Patients with cochlear implants (CIs) who were educated in hearing rehabilitation schools were included in the study. A total of 175 children were operated on for cochlear implantation between August 2019 and August 2021 in the department of otorhinolaryngology at different centers in Turkey, and while 16 (9.1%) of those patients had auditory neuropathy spectrum disorder (ANSD), 159 (90.9%) had sensorineural hearing loss (SNHL). Differences in auditory perception between the two groups were examined. Auditory perception tests were applied for these patients 6 months after CI surgery. The auditory perception performances of the patients were evaluated with the Evaluation of Auditory Responses to Speech (EARS) battery, including the Littlears, Lip, Bıs4, Bıs12, Cap, Sır, Mtp-3, Mtp-6, Mtp-12, Matrix A1, and Gasp tests. All patients had profound bilateral SNHL. Four auditory perception tests (Littlears, Bıs-12, Sır, Matrix A1) showed similar results between patients with ANSD and SNHL, but seven auditory perception tests (Lıp, Bıs-4, Cap, Mtp-3, Mtp-6, Mtp-12, Gasp) showed significantly higher results among patients with SNHL. Hyperbilirubinemia, prematurity, consanguineous marriage, and family history of hearing loss were found to be common among patients with ANSD. ANSD patients who do not benefit from hearing aids benefit from CI surgery.

Uneventful Cochlear Implantation through Round Window Approach in a Child with Persistent Stapedial Artery: A Case Report

Persistent stapedial artery (PSA) is a rare congenital vascular anomaly, with both clinical and surgical implications. When encountered during middle ear surgery, it represents a challenge to the otologic surgeon, since damage to this artery could lead to massive intraoperative bleeding and poor surgical exposure. Here we report the case of a 3-year-old boy with prelingual and profound bilateral sensorineural hearing loss who was referred to our Otolaryngology-Head and Neck Surgery Department for cochlear implant evaluation. Pre-operative computed tomography (CT) examination of the temporal bone confirmed the diagnosis of PSA. Further evaluation showed no contraindication for surgery and the patient underwent cochlear implantation using the classic transmastoid, facial recess approach. During surgery the vessel was coursing far enough from the round window niche, making it possible to achieve safe and complete electrode insertion into the scala tympani of the cochlear basal turn. This case demonstrates that cochlear implantation is safe and feasible in patients with PSA. Thorough analysis of the preoperative temporal bone CT scan might help with surgical planning by identifying this anomaly prior to surgery.

Robotic cochlear implantation in post-meningitis ossified cochlea

AimTo report the experience of an image-guided and navigation-based robot arm as an assistive surgical tool for cochlear implantation in a case with a labyrinthitis ossificans. PatientA 55-years-old man with a history of childhood meningitis whose hearing deteriorated progressively to bilateral profound sensorineural hearing loss. InterventionRobotic Assisted Cochlear Implant Surgery (RACIS) with a straight flexible lateral wall electrode. Primary outcome measuresElectrode cochlear insertion depth with RACIS with facial recess approach and autonomous inner ear access with full electrode insertion of a flexible straight cochlear implant array. ConclusionsIntra cochlear ossifications pose a challenge for entering the cochlea and full-length insertion of a cochlear implant. RACIS has shown that computations of radiological images combined with navigation-assisted robot arm drilling can provide efficient access to the inner ear.

Childhood meningitis and delay of four years in diagnosing bilateral profound sensorineural hearing loss: a case report

Globally around 34 million children present disabling hearing loss. If unaddressed, hearing loss can negatively impact several aspects such as communication, cognition, language, and speech. Most needy people with hearing impairment do not have access to treatments and it’s a national and international public health problem. Meningococcal disease is caused by the bacterium Neisseria meningitides, affects mainly children, can cause hearing loss, and is a global public health challenge. This study aimed to present the case report of a child who acquired meningococcal disease and bilateral profound sensorineural hearing loss in primary infancy. At the age of six months, the child acquired meningococcal meningitis and performed antibiotic therapeutics. Four years later, the audiometric evaluation detected hearing loss. At the age of seven years, the patient started speech language therapy sessions. At the age of nine years, hearing prostheses were provided by a hospital. At the age of ten, the child began to deny the use of hearing aids at home and school. Two years later, she started her studies at a special school where the deaf community is clearly present. At the age of fourteen, the patient became completely fluent in Sign language, stopping speech therapy sessions. The analyzed case demonstrated a lack of children’s surveillance by a multidisciplinary team and the relevance of following children’s guidance vaccination. It is required to provide adequate interventions for children with hearing loss, which can potentially aid them to develop their skills and to achieve a better quality of life.

Younger Age at Cochlear Implant Activation Results in Improved Auditory Skill Development for Children With Congenital Deafness.

The U.S. Food and Drug Administration indications for cochlear implantation in children is currently 9 months of age and older for children with bilateral profound sensorineural hearing loss (SNHL). Studies have shown that earlier activation of a cochlear implant (CI) can lead to better spoken language outcomes. As auditory skills are a precursor to the development of spoken language, this study was developed to investigate the influence of age at CI activation on auditory skill acquisition in young children. A secondary aim was to describe the auditory skills of children implanted prior to 9 months of age as compared to children with older ages of activation. Functional Listening Index (FLI) scores obtained during routine clinical visits were reviewed for 78 pediatric CI recipients with congenital bilateral profound hearing loss who were activated before 2 years of age. A linear mixed-effects model assessed the effect of age at CI activation on cumulative FLI scores over time. There was a significant interaction between age at activation and chronological age at the time of evaluation, indicating that children with earlier access to sound achieved a greater number of auditory skills than those with later CI activations when measured at the same chronological age. Children activated before the age of 9 months approximated scores expected of children with typical hearing, whereas children activated between 9 and 24 months of age did not. Younger age at CI activation is associated with increased auditory skills over time. Children who undergo cochlear implantation and CI activation before 9 months achieve more auditory skills by 4 years of age than children who are activated at later ages. These data suggest that reducing the approved age at cochlear implantation for children with congenital bilateral profound SNHL may support optimal auditory skill acquisition.