Hearing-impaired Infants Research Articles

Cost-effectiveness of portable-automated ABR for universal neonatal hearing screening in India.

The World Health Organization considers Universal Neonatal Hearing Screening (UNHS) essential to global public health. Rashtriya Bal Swasthya Karyakram has included newborn hearing screening in India since 2013. The program faces human, infrastructure, and equipment shortages. First-line hearing screening with improved diagnostic accuracy is needed. The Portable Automated Auditory Brainstem Responses (P-AABR) can be used in remote areas for UNHS due to its low infrastructure needs and diagnostic accuracy. This study evaluated the cost-effectiveness of P-AABR in UNHS. We employed an analytical model based on decision trees to assess the cost-effectiveness of Otoacoustic Emission (OAE) and P-AABR. The total cost to the health system for P-AABR, regardless of true positive cases, is INR 10,535,915, while OAE costs INR 7,256,198. P-AABR detects 262 cases, whereas OAE detects 26 cases. Portable Automated ABR costs INR 97 per case detection, while OAE costs INR 67. The final ICER was 97407.69. The P-AABR device is cost-effective, safe and feasible for UNHS Rashtriya Bal Swasthya Karyakram (RBSK) programs. Beyond reducing false referrals and parent indirect costs, it detects more hearing-impaired infants. Even in shortages of skilled workers, existing staff can be trained. Thus, this study suggests integrating this device into community and primary health centers to expand UNHS coverage.

A study to evaluate the burden of hearing loss and its correlation with risk factors among high-risk infants at a teaching institution, Jaipur.

Hearing loss is a global issue of hearing disability and early detection and rehabilitation of hearing loss are important for the development of speech and language skills in hearing-impaired infants. There are multiple risk factors that aid in hearing loss but some are potential factors that contribute toward hearing loss in infants. The aim of this study was to assess the burden of hearing loss and its correlation with risk factors among high-risk infants at a teaching institution in Jaipur, Rajasthan. This study was carried out after approval of institutional ethics committee on a total of 320 high-risk infants at RUHS College of medical sciences and associated hospitals. Hearing loss was assessed by brainstem evoked response audiometry (BERA). Statistical analysis of data was done by cross-tabulation analysis with Pearson correlation and quantile regression. Out of 320 high-risk infants, 59.69% of infants had normal hearing, 9.09% Unilaterally hearing impaired, 20.31% were bilaterally mild-moderate hearing loss, and 10.94% had severe-profound deafness. The prevalence of important risk factors viz. hyperbilirubinemia, low birth weight, appearance, pulse, grimace, activity, and respiration score, meconium aspiration, respiratory distress, and ventilation greater than five days were 86%, 58.9%, 40%, 36%, 29%, and 22%, respectively. In high-risk infants, hearing loss is a common hearing disorder. Because of this, early diagnosis of hearing loss gives them the best chance of developing functional speech. Brainstem evoked response audiometry is a simple, reliable, and effective technique for the assessment of auditory functions in infants.

Genetic screening of 15 hearing loss variants in 77,647 neonates with clinical follow-up.

To analyze the genotype distribution and frequency of hearing loss genes in newborn population and evaluate the clinical value of genetic screening policy in China. Genetic screening for hearing loss was offered to 84,029 neonates between March 2019 and December 2021, of whom 77,647 newborns accepted the screening program with one-year follow-up. The genotyping of 15 hot spot variants in GJB2, GJB3, SLC26A4, and MT-RNR1 was performed on microarray platform. A total of 3.05% (2369/77,647) newborns carried at least one genetic hearing loss-associated variant, indicated for early preventive management. The carrier frequency of GJB2 gene was the highest, at 1.48% (1147/77,647), followed by SLC26A4 gene at 1.07% (831/77,647), and GJB3 gene at 0.23% (181/77,647). GJB2 c.235delC variant and SLC26A4 IVS7-2A>G variant were the most common allelic variants with allele frequency of 0.6304% (979/155,294) and 0.3992% (620/155,294), respectively. 10 children are identified as homozygous or compound heterozygous for pathogenic variants (4 in GJB2, 6 in SLC26A4), and 7 of these infants had passed the hearing screening. Following up of the genetically screened newborns revealed that genetic screening detected more hearing-impaired infants than hearing screening alone. Genetic screening helped identify the infants who had passed the initial hearing screening, and reduced time for diagnosis and intervention of hearing aid. In addition, we identified 234 newborns (0.30%, 234/77,647) susceptible to preventable aminoglycoside antibiotic ototoxicity undetectable by hearing screening. We performed the largest-scale neonatal carrier screening for hearing loss genes in Southeast China. Our results indicated that genetic screening is an important complementation to conventional hearing screening. Our practice and experience may facilitate the application and development of neonatal genetic screening policy in mainland China.

Neurobehavioral effects of general anesthesia and cochlear implantation on hearing-impaired infants: A prospective observational cohort study.

The potential adverse effects of prolonged exposure to anesthetics in pediatric patients with severe-to-profound sensorineural hearing loss remain unclear. This study aimed to examine whether early bilateral cochlear implantation involving long-duration anesthetic exposure caused greater developmental impairment than that with unilateral cochlear implantation. This prospective observational study included normally developing infants with bilateral severe-to-profound sensorineural hearing loss aged 6 months to 2 years who were candidates for unilateral/bilateral cochlear implantation surgery. Baseline (T0), 6-month (T1), and 1-year (T2) Gesell Scale scores were measured. The outcomes included fine motor, adaptability, gross motor, language, and social skills scale 6 and 12 months postoperatively. The 90 enrolled children with bilateral severe-to-profound sensorineural hearing loss (unilateral n=43; bilateral n=47) had a younger bilateral group (11.00±3.66vs. 15.63±6.99 months, p<.001). Anesthesia duration was longer in the bilateral group (271.57±36.09vs. 148.81±25.60min, p < .001). Gross motor, fine motor, adaptability, and language scores improved in both groups, and no significant between-group differences occurred in the fine motor scale at T1 and T2. Language developmental quotients improved significantly in the bilateral group compared with the unilateral group at T1 (mean differences: 25.07±4.37vs. 10.88±4.61, p < .001) and T2 (mean differences: 34.98±5.94vs. 15.28±6.55, p < .001). Stepwise regression revealed that gross motor, adaptability, language, and social skill developmental quotients at T1 were positively correlated with those at T0. Gross motor, fine motor, and social skill developmental quotients at T2 were negatively correlated with age at operation. Language developmental quotients were positively correlated with T0 values (p < .001) and in the bilateral group (p < .001) at T1 and T2. When evaluating young children with bilateral severe-to-profound sensorineural hearing loss, despite longer exposures to general anesthesia, bilateral cochlear implantations were associated with more improvement in language scores and no differences in other skills compared with those with only unilateral implantation.

Acoustic change complex for assessing speech discrimination in normal-hearing and hearing-impaired infants

ObjectiveThis study examined (1) the utility of a clinical system to record acoustic change complex (ACC, an event-related potential recorded by electroencephalography) for assessing speech discrimination in infants, and (2) the relationship between ACC and functional performance in real life. MethodsParticipants included 115 infants (43 normal-hearing, 72 hearing-impaired), aged 3–12 months. ACCs were recorded using [szs], [uiu], and a spectral rippled noise high-pass filtered at 2 kHz as stimuli. Assessments were conducted at age 3–6 months and at 7–12 months. Functional performance was evaluated using a parent-report questionnaire, and correlations with ACC were examined. ResultsThe rates of onset and ACC responses of normal-hearing infants were not significantly different from those of aided infants with mild or moderate hearing loss but were significantly higher than those with severe loss. On average, response rates measured at 3–6 months were not significantly different from those at 7–12 months. Higher rates of ACC responses were significantly associated with better functional performance. ConclusionsACCs demonstrated auditory capacity for discrimination in infants by 3–6 months. This capacity was positively related to real-life functional performance. SignificanceACCs can be used to evaluate the effectiveness of amplification and monitor development in aided hearing-impaired infants.

Analysis of specific risk factors of neurodevelopmental disorder in hearing-impaired infants under ten months of age: "EnTNDre" an opening research stemming from a transdisciplinary partnership.

Approximately 20% of children born with severe to profound hearing loss (HL) have an associated disorder that poses a neurodevelopmental risk [1]. The objective of this study is to identify the criteria and profiles of deaf infants at risk of neurodevelopmental disorders (NDD) to provide early intervention. Twenty-two infants aged three to ten months with bilateral congenital deafness were included. Each child attended a consultation with a psychiatrist specializing in the development of hearing-impaired infants as part of their ENT follow-up. The quality of their early development was analyzed using the Olliac grid and well-known postural and sensorimotor criteria. The children were then classified into three groups: normal examination (Group 1), evident NDD (Group 2), and intermediate examination (Group 3). Early medical history, the etiology of deafness, cerebral imaging, and vestibular test results were collected and compared in the different groups. The average age of the children at the time of observation was seven months (3-10 months). All had sensorineural HL, with identified causes in 13 out of 22 cases: five cases of connexin 26 gene mutation, three cases of CHARGE syndrome, two CMV infections, one Usher syndrome, one GATA3 mutation, and one LHPL5 mutation. The average score on the Olliac grid was nine (0-15), and abnormal postural and sensorimotor behaviors were found in 15 cases out of 22 (68%). 27% of the children were classified in Group 1, 45% in Group 2, and 27% in Group 3. Children with non-isolated HL, abnormal brain MRI (8/22), malformations outside the auditory system (10/22), vestibular impairments (9/22), and/or CMV infections (2/22) were distributed as follows: 2/6 in Group 1, 9/10 in Group 2, and 3/6 in Group 3. 8/22 children had suffered perinatal complications (0/6 in Group 1, 6/10 in Group 2, and 2/5 in Group 3). Only one child had a first-degree relative with NDD. He belonged to Group 2. To our knowledge, this paper is the first to describe the development of infants with congenital deafness. It is based on an observation time that had been included in the procedure of multidisciplinary evaluations prior to cochlear implantation (CI), thanks to the partnership between a psychiatric center for deaf children and an ENT-pediatric implantology service. This consultation was aimed at assessing the quality of neurodevelopment and identifying NDD without a specific referral, with good acceptability for families. Using the Olliac grid and postural and sensorimotor criteria developed to be assessed in the routine care consultation, we identified evident early signs of NDD in 45% of infants. This group (Group 2) requires early, targeted, developmental support. Some children in an intermediate zone (Group 3) require further observation and support. The very early identification of NDD seems to be relevant in the care of hearing-impaired infants. The use of the Olliac grid and developmental scales seems relevant to identifying infants at risk for NDD.

Analysis of the Latency of Auditory Brainstem Response Wave V in Infants According to Age, Hearing Threshold and Stimulus Intensity

Background and Objectives The latency of auditory brainstem response (ABR) wave V shifts depending on age, hearing threshold, and stimulus intensity. This study was performed to examine the latencies of ABR wave V in infants with normal hearing and sensorineural hearing loss.Subjects and Method The retrospective review of ABR of 318 infants (539 ears) was performed. The patients were divided into four groups according to age at the time of the ABR test (group A: 0-2 months, group B: 3-5 months, group C: 6-8 months, and group D: 9-11 months). The test was performed using click sound under sedation, with the stimulus intensity adjusted by 10 dB intervals. The latency of wave V was analyzed according to age, hearing threshold, and stimulus intensity.Results Normal hearing was detected in 320 ears (wave V threshold of 20 dBnHL or less) and sensorineural hearing loss was found in 219 ears. Wave V latencies decreased with increase in age and stimulus intensity in both normal hearing infants and hearing-impaired infants. The ears with higher thresholds showed longer latencies at the same stimulus intensity. The normative data of wave V latency of infants with varying hearing thresholds according to age and stimulus intensity could be determined.Conclusion The present study examined the latencies of ABR wave V of hearing-impaired and normal hearing infants according to age and stimulus intensity. The data will help audiologists to evaluate the hearing of infants who are referred for ABR test.

Modified T2 Statistics for Improved Detection of Aided Cortical Auditory Evoked Potentials in Hearing-Impaired Infants.

The cortical auditory evoked potential (CAEP) is a change in neural activity in response to sound, and is of interest for audiological assessment of infants, especially those who use hearing aids. Within this population, CAEP waveforms are known to vary substantially across individuals, which makes detecting the CAEP through visual inspection a challenging task. It also means that some of the best automated CAEP detection methods used in adults are probably not suitable for this population. This study therefore evaluates and optimizes the performance of new and existing methods for aided (i.e., the stimuli are presented through subjects' hearing aid(s)) CAEP detection in infants with hearing loss. Methods include the conventional Hotellings T2 test, various modified q-sample statistics, and two novel variants of T2 statistics, which were designed to exploit the correlation structure underlying the data. Various additional methods from the literature were also evaluated, including the previously best-performing methods for adult CAEP detection. Data for the assessment consisted of aided CAEPs recorded from 59 infant hearing aid users with mild to profound bilateral hearing loss, and simulated signals. The highest test sensitivities were observed for the modified T2 statistics, followed by the modified q-sample statistics, and lastly by the conventional Hotelling's T2 test, which showed low detection rates for ensemble sizes <80 epochs. The high test sensitivities at small ensemble sizes observed for the modified T2 and q-sample statistics are especially relevant for infant testing, as the time available for data collection tends to be limited in this population.

Three Years of Vestibular Infant Screening in Infants With Sensorineural Hearing Loss.

Although vestibular deficits are more prevalent in hearing-impaired children and can affect their development on many levels, a pediatric vestibular assessment is still uncommon in clinical practice. Since early detection may allow for timely intervention, this pioneer project has implemented a basic vestibular screening test for each six-month-old hearing-impaired infant in Flanders, Belgium. This study aims to report the vestibular screening results over a period of three years and to define the most important risk factors for abnormal vestibular screening results. Cervical Vestibular Evoked Myogenic Potentials with bone-conduction were used as a vestibular screening tool in all reference centers affiliated to the Universal Newborn Hearing Screening Program in Flanders. From June 2018 until June 2021, 254 infants (mean age: 7.4 months, standard deviation: 2.4 months) with sensorineural hearing loss were included. Overall, abnormal vestibular screening results were found in 13.8% (35 of 254) of the infants. The most important group at risk for abnormal vestibular screening results were infants with unilateral or bilateral severe to profound sensorineural hearing loss (20.8%, 32 of 154) (P < .001, odds ratio = 9.16). Moreover, abnormal vestibular screening results were more prevalent in infants with hearing loss caused by meningitis (66.7%, 2 of 3), syndromes (28.6%, 8 of 28), congenital cytomegalovirus infection (20.0%, 8 of 40), and cochleovestibular anomalies (19.2%, 5 of 26). The vestibular screening results in infants with sensorineural hearing loss indicate the highest risk for vestibular deficits in severe to profound hearing loss, and certain underlying etiologies of hearing loss, such as meningitis, syndromes, congenital cytomegalovirus, and cochleovestibular anomalies.

Vestibular Infant Screening (VIS)\u2013Flanders: results after 1.5\xa0years of vestibular screening in hearing-impaired children

Due to the close anatomical relationship between the auditory and vestibular end organs, hearing-impaired children have a higher risk for vestibular dysfunction, which can affect their (motor) development. Unfortunately, vestibular dysfunction often goes unnoticed, as vestibular assessment in these children is not standard of care nowadays. To timely detect vestibular dysfunction, the Vestibular Infant Screening–Flanders (VIS–Flanders) project has implemented a basic vestibular screening test for hearing-impaired infants in Flanders (Belgium) with a participation rate of 86.7% during the first year and a half. The cervical Vestibular Evoked Myogenic Potentials (cVEMP) test was applied as vestibular screening tool to map the occurrence of vestibular (mainly saccular) dysfunction in this population. At the age of 6 months, 184 infants were screened. No refers on vestibular screening were observed in infants with permanent conductive hearing loss. In infants with permanent sensorineural hearing loss, a cVEMP refer rate of 9.5% was observed. Failure was significantly more common in infants with severe-profound compared to those with mild-moderate sensorineural hearing loss (risk ratio = 9.8). Since this is the first regional study with a large sample size and successful participation rate, the VIS–Flanders project aims to set an example for other regions worldwide.

The language development status of the hearing-impaired infants in Special Needs Education Schools for the Deaf: Nationwide survey in Japan

要旨: 全国聴覚特別支援学校の 2～5歳児教師に, 担当幼児の言語発達状況および保護者の指導連携について調査した。99校中64校 (回収率64.6%) の教師258名の回答から聴覚障害幼児984名について検討した。その結果, 軽中等度難聴が28.1%, 高重度難聴71.9%であり, 重度難聴の69.4%で人工内耳を装用し, 75.2%は聴覚口話法と手話法等を併用していた。言語発達状況は, 2歳児では 1 歳未満～1 歳レベル児が69.4%であり, 学齢が上の児ほど4～5歳レベル児の割合が増えたが, 5歳児でも65.5%に留まった。保護者への指導目標は, 1 歳未満～1 歳レベル児の55.3%で2～3歳レベルの課題 (模倣誘導・発話修正) を, 4～5歳レベル児の84.3%に4～5歳レベルの課題 (語彙拡充・語義説明) が設定されていた。児の言語発達水準には, 教師の指導経験, 保護者への適切な目標設定が関与し, 専門性の向上と実践の蓄積, および保護者との連携の重要性が示唆された。

An acoustic and auditory analysis of vocants in infants with cochlear implants

Introduction The duration of the nuclei is a crucial factor for the shift of prelexical to mature speech, since control of duration is closely related with improved speech intelligibility. Objectives This work records the suprasegmental feature of duration in infants with normal hearing (NH) compared to those with cochlear implants (CI) based on vocant productions (quasivowels and full vowels). Materinals and Methods In this longitudinal study, 102 vocant productions were analyzed from cases of congenitally hearing-impaired infants (implantation ages 1:4 and 1:11 years; post-implant ages 0:6 months and 1:3 years) who were matched with three NH infants of similar hearing experience (ages 0:8–0:11 months). Current methodology analyzes vocants using a combination of acoustical and auditory analyses. Vegetative data or reflexive sounds were excluded. Participants had had unknown deafness etiology and no other disabilities. Duration was measured using wideband spectrographic analysis, from voice onset to the loss of audible signal and the decrease of higher formant’s energy. Results The results showed that the mean vocant duration of young CI users was longer, compared to hearing matched peers during the first six months after cochlear implantation. Conclusions This recorded weakness for CI users' speech production is a challenge for future work in speech processing strategies. This is the first study measuring production of vocants during the pre-linguistic stage in CI recipients.

Nationwide population genetic screening improves outcomes of newborn screening for hearing loss in China

PurposeThe benefits of concurrent newborn hearing and genetic screening have not been statistically proven due to limited sample sizes and outcome data. To fill this gap, we analyzed outcomes of newborns with genetic screening results. MethodsNewborns in China were screened for 20 hearing-loss–related genetic variants from 2012 to 2017. Genetic results were categorized as positive, at-risk, inconclusive, or negative. Hearing screening results, risk factors, and up-to-date hearing status were followed up via phone interviews. ResultsFollowing up 12,778 of 1.2 million genetically screened newborns revealed a higher rate of hearing loss by three months oF.A.ge among referrals from the initial hearing screening (60% vs. 5.0%, P < 0.001) and a lower rate of lost-to-follow-up/documentation (5% vs. 22%, P < 0.001) in the positive group than in the inconclusive group. Importantly, genetic screening detected 13% more hearing-impaired infants than hearing screening alone and identified 2,638 (0.23% of total) newborns predisposed to preventable ototoxicity undetectable by hearing screening. ConclusionIncorporating genetic screening improves the effectiveness of newborn hearing screening programs by elucidating etiologies, discerning high-risk subgroups for vigilant management, identifying additional children who may benefit from early intervention, and informing at-risk newborns and their maternal relatives of increased susceptibility to ototoxicity.

Pilot implementation of newborn hearing screening programme at four hospitals in southern Thailand.

ObjectiveTo determine the effectiveness and benefit of a universal newborn hearing screening programme at four different hospitals in southern Thailand, between January and July 2017.MethodsOne screener per hospital recorded demographic data of all newborns and their exposure to risk of hearing loss, and evaluated their hearing by transient otoacoustic emission technology. Those who demonstrated bilateral moderate to profound hearing loss at both a first and second screening were referred for diagnostic assessment. Those with confirmed hearing loss received treatment and regular follow-up appointments, and their speech development was assessed at 1 year of age. We determined effectiveness by comparing our achieved coverage and proportion of follow-up and referrals with benchmarks set by the American Academy of Pediatrics (≥ 95%, ≥ 95% and ≤ 4%, respectively), and determined benefit by calculating the composite language scores of hearing-impaired infants who received early intervention.FindingsWe screened 6140 eligible newborns, and achieved a screening coverage of 95.4% (5859/6140), lost 25.7% (63/245) and 22.0% (9/41) to follow-up at the second screening and diagnostic assessment stages, respectively, and obtained an overall proportion of referrals of 0.7% (41/6140). Twelve infants were confirmed as having hearing loss and received early intervention; nine (75%) demonstrated normal speech development by their first birthday. Our universal hearing screening yielded a prevalence of sensorineural hearing loss of less than 0.1% (3/6140).ConclusionAlthough ineffective by American Academy of Pediatrics standards, we demonstrated the benefit of early intervention in infants diagnosed with hearing loss.

Early intervention for hearing-impaired infants in Special Needs Education Schools for the Deaf: Nationwide survey in Japan

Early intervention for hearing-impaired infants in Special Needs Education Schools for the Deaf: Nationwide survey in Japan

Vocalization frequency as a prognostic marker of language development following early cochlear implantation.

Despite their potential significance for later linguistic outcomes, early aspects of vocalization had been seriously undervalued in the past, and thus, minimally investigated until relatively recently. The present article sets out to critically examine existing evidence to: i) ascertain whether vocalization frequency (volubility) posits a plausible marker of cochlear implantation success in infancy, and ii) determine the clinical usefulness of post-implementation vocalization frequency data in predicting later language development. Only recent peer-reviewed articles with substantial impact on vocalization growth during the first year of life, examining sound production characteristics of normally hearing (NH) and hearing impaired infants fitted with cochlear implantation (CI) were mentioned. Recorded differences in linguistic performance among NH and CI infants are typically attributed to auditory deprivation. Infants who have undergone late CI, produce fewer syllables (low volubility) and exhibit late-onset babbling, especially those who received their CIs at the age of 12 months or thereafter. Contrarily, early recipients (before the 12-month of age) exhibit higher volubility (more vocalizations), triggered from CI-initiated auditory feedback. In other words, early CI provides infants with early auditory access to speech sounds, leading to advanced forms of babbling and increased post-implementation vocalization frequency. Current findings suggest vocalization frequency as a plausible criterion of the success of early CI. It is argued that vocalization frequency predicts language development and affects habilitation therapy.

Assessing and monitoring the impact of the national newborn hearing screening program in Israel

BackgroundThe Israeli Newborn Hearing Screening Program (NHSP) began operating nationally in January 2010. The program includes the Otoacoustic Emissions (OAE) test for all newborns and Automated Auditory Brainstem Response (A-ABR) test for failed OAE and infants at risk for auditory neuropathy spectrum disorders. NHSP targets are diagnosis of hearing impairment by age three months and initiation of habilitation by six months.Objectives(1) Review NHSP coverage; (2) Assess NHSP impact on age at diagnosis for hearing impairment and age at initiation of habilitation; (3) Identify contributing factors and barriers to NHSP success.Methods(1) Analysis of screening coverage and referral rates for the NHSP; (2) Analysis of demographic data, results of coverage, age at diagnosis and initiation of habilitation for hearing impaired infants pre-implementation and post-implementation of NHSP from 10 habilitation centers; (3) Telephone interviews with parents whose infants failed the screening and were referred for further testing.ResultsThe NHSP coverage was 98.7% (95.1 to 100%) for approximately 179,000 live births per year for 2014–2016 and average referral rates were under 3%. After three years of program implementation, median age at diagnosis was 3.7 months compared to 9.5 months prior to NHSP. The median age at initiation of habilitation after three years of NHSP was 9.4 months compared to 19.0 prior to NHSP. Parents (84% of 483 sampled) with infants aged 4–6 months participated in the telephone survey. While 84% of parents reported receiving a verbal explanation of the screening results, more than half of the parents reported not receiving written material. Parental report of understanding the test results and a heightened level of concern over the failed screen were associated with timely follow-up.ConclusionsThe findings indicate high screening coverage. The program reduced ages at diagnosis and initiation of habilitation for hearing impaired infants. Further steps needed to streamline the NHSP are improving communication among caregivers to parents to reduce anxiety; increasing efficiency in transferring information between service providers using advanced technology while ensuring continuum of care; reducing wait time for follow-up testing in order to meet program objectives. Establishment of a routine monitoring system is underway.

Acoustic Analysis of Crying Signal in Infants with Disabling Hearing Impairment

Crying is a multimodal, dynamic behavior and the first way to communicate. Early identification of hearing impairment is critical for prevention of speech and language disorders. The present study aimed to assess the acoustic features of infant's cry signals to find possible differences between two groups including hearing-impaired (HI) infants and normal hearing (NH) control. The data were collected from 34 (17 HI, 17 NH) infants under 2 months of age. Recording of the infant cry signals was collected during the examination of the Babinski reflex and was subsequently submitted for acoustic analysis. The total duration of the recording for each infant was approximately 30 seconds. The acoustical features included fundamental frequency (F0), formants (F1, F2, and F3), intensity, jitter, shimmer, ratios of F2/F1 and F3/F1, ratio of harmonic to noise, and voice break. The recording device was an Olympus ws-321M voice recorder with 44,100Hz sampling frequency in the stereo form. Praat analysis software (version 27, 3, 5) was used to analyze the crying signals. The data were then statistically analyzed using SPSS version 21. Acoustic analysis of the crying signals showed that HI infants have lower intensity and higher F0 and voice break than NH infants. However, the other differences were not statistically significant. The results of the present study demonstrated that the acoustic components including F0, intensity, and voice break may be used as indices to discriminate HI infants from NH infants under 2 months of age. These findings can be increased our knowledge concerning the functional mechanisms of the vocal organ in HI and NH infants.

Support system for hearing-impaired infants and young children with multiple disabilities at Hiroshima City Child Care and Guidance Center

Support system for hearing-impaired infants and young children with multiple disabilities at Hiroshima City Child Care and Guidance Center

Vocal turn-taking between mothers and their hearing-impaired infants with cochlear implants

Normal-hearing (NH) infants participate in social exchanges soon after birth. What does the temporal organization of vocal turn-taking (VTT) look like in infants with hearing loss with cochlear implants? This study examined VTT during spontaneous play in eight dyads of mothers and their hearing-impaired (HI) or age-matched NH infants (mean age 17.4 m at time 1). Dyads came to two sessions, corresponding to 3 and 12 months post-implantation. Analyses demonstrated that although HI infants vocalized less than NH infants, the proportion of vocalizations involved in VTT exceeded that from NH infants at time 1 and was equal at time 2. For vocalizations involved in VTT, there was a higher proportion of simultaneous speech in HI dyads compared to NH dyads at time 1, but the direction reversed at time 2. At time 1, the number of turns was greater in the HI group but decreased compared to the NH group at time 2. Duration of between-speaker pauses (BSP) was shorter in infant-mother compared to mother-infant turns in the NH group only. At time 2, the duration of BSP was shorter in infant-mother compared to mother-infant turns in both groups. The results suggest that infant hearing status affects temporal characteristics of VTT.