听觉及言语发育观察表可用性初探

目的分析婴幼儿听性脑干反应（ABR）结果与听觉及言语发育评估的相关性,探讨听觉及言语发育观察表在农村地区婴幼儿听力保健中的可用性。方法采用听觉及言语发育观察表和听性脑干反应对136例受试者（年龄3～18个月,平均5个月）进行测试,分析两种测试结果的相关性。结果①ABR测试结果：136例中双耳听力正常76人,单耳听力损失27人,双耳听力损失33人（轻度13人,中度2人,重度13人,极重度5人）。②听觉及言语发育观察结果：听力损失程度不同听觉及言语发育观察表的通过率亦不同,双耳昕力正常组、单耳听力损失组、双耳轻度听力损失组、双耳中度听力损失组、双耳重度听力损失组、双耳极重度听力损失组通过率分别为98。68％、92．59％、92．31％、50％、15．38％和0％。结论听力正常的婴幼儿能很好地做到与其月龄相对应的听觉及言语发育观察表中的项目,通过率高;随着听力损失程度的加重,通过率逐渐降低。在农村地区应用听觉及言语发育观察表作为听力监测的一种方法,可弥补现阶段听力筛查中的不足。     

婴幼儿听觉能力评估

1背景随着新生儿听力筛查工作在全国不断普及和临床听力诊断技术不断提高,越来越多的耳聋婴幼儿,特别是重度和极重度聋婴幼儿在出生后不久即可确诊。近年来,各种助听装置,如助听器、人工耳蜗技术不断提高,选配和调试方法不断改进,已有越来越多的婴幼儿使用这些助听装置获得或改善听力。早期发现、早期诊断和早期干预已成为可能。随着干预年龄日趋低龄化,如何确定助听装置使用标准及评估助听装置对耳聋婴幼儿听觉功能的帮助,成为听力学工作者面临的一项极具挑战性的工作。     

听力筛查未通过婴幼儿的客观听力评估

目的 分析听力筛查未通过婴幼儿的客观听力学特征,为早期干预提供科学依据。方法 对听力筛查未通过患儿286例进行听力诊断性检查。采用听性脑干反应(ABR)、40Hz听觉相关电位(40Hz-AERP)、畸变产物耳声发射(DPOAE)、声导抗进行评估。结果 286例婴幼儿中双耳听力正常95例(33.22%);听力损失者191例(66.78％),其中单耳听力损失70例(24.47％),双耳听力损失121(42.31％);传导性听力损失59例(20.63%),感音神经性听力损失132例(46.15%);轻度听力损失91例(31.82%),中度43例(15.03%),重度20例(6.99％),极重度37例(12.94％)。191例听力异常者只有16例复查,占8.38％,复查结果：听力正常2例,双耳听力损失10例,单耳听力损失4例。结论 部分听力筛查未通过婴幼儿的听力可随着听觉神经系统发育的完善恢复正常;同时中耳病变也是部分婴幼儿听力筛查未通过的影响因素;客观听力学组合测试可有效评估听力筛查未通过患儿的听力特征,为听力损失的早期诊断、早期干预提供科学依据;听力异常患儿的复查率低和失访率高仍是目前亟需解决的问题。     

脑性瘫痪伴听力损失儿童的听力学特点及高危因素分析

目的探讨脑性瘫痪伴听力损失儿童的听力学特点及高危因素。方法对2009年1月～2010年12月诊断为脑性瘫痪的120例患儿进行听力学诊断,包括ABR、诊断型DPOAE测试,明确是否伴有听力损伤及听损伤的程度和部位,并对听力损伤的高危因素进行分析。结果 120例脑性瘫痪儿童中,双耳ABR反应阈正常82例(68.33%,82/120),其DPOAE均正常;38例(31.67%,38/120)ABR异常,其中,双耳35例,3例轻度、5例中度、3例重度、24例极重度;单耳3例,2例极重度、1例中度听力损失;23例双耳、3例单耳DPOAE未引出,与ABR检查结果一致,符合感音神经性聋诊断;12例双耳DPOAE正常,而ABR波形异常,符合蜗后聋诊断。38例听损伤脑瘫患儿的高危因素主要有高胆红素血症13例(34.21%)、窒息8例(21.05%)、早产低体重8例(21.05%),母孕期感染7例(18.42%)、伴其它新生儿疾病(先天性甲状腺机能低下症、败血症、化脓性脑膜炎、面神经麻痹等)6例(15.79%),脑瘫或耳聋家族史2例(5.26%),有两种或两种以上高危因素者11例。结论本组脑性瘫痪伴听力损失儿童以双耳极重度感音神经性聋为主,其次为双耳极重度蜗后聋,多数脑瘫伴听力损失儿童具有听力损伤高危因素。     

先天性语前聋中国儿童双耳人工耳蜗植入疗效观察

目的：评估双侧耳人工耳蜗植入对极重度感音神经性语前聋患儿的听觉与言语康复疗效。方法：2例先天性极重度感音神经性聋儿童，单侧耳人工耳蜗植入术后2年和3年分别施行对侧耳人工耳蜗植入。术后1年评估患儿左、右耳单耳及双耳人工耳蜗助听听阈和言语识别率。以及言语清晰度。结果：①双耳人工耳蜗助听与单耳人工耳蜗助听相比。平均听阈降低分别为13dB和11dB；②在安静环境中双耳人工耳蜗植入儿童的言语识别率(开放项列)分别平均提高为9％和10％，2例双耳人工耳蜗植入儿童的言语识别率(开放项列)分别达97％和95％；③在嘈杂环境中对言语的识别能力明显提高；④言语清晰度有明显改善。结论：双耳人工耳蜗植入可明显提高极重度感音神经性语前聋患儿在安静和噪声环境下的言语识别率，对语前聋儿童的言语和语言发育有明显的帮助。     

中国第二次残疾人抽样调查听力残疾标准介绍

1听力残疾定义及分级1.1听力残疾的定义听力残疾,是指人由于各种原因导致双耳不同程度的永久性听力障碍,听不到或听不清周围环境声及言语声,以致影响日常生活和社会参与。1.2听力残疾的分级听力残疾一级听觉系统的结构和功能方面极重度损伤,较好耳平均听力损失≥91dB HL,在无助听设备帮助下,不能依靠听觉进行言语交流,在理解和交流等活动上极度受限,在参与社会生活方面存在极严重障碍。听力残疾二级听觉系统的结构和功能重度损伤,较好耳平均听力损失在81~90dB HL之间,在无助听设备帮助下,在理解和交流等活动上重度受限,在参与社会生活方…     

未通过听力筛查婴幼儿的听力诊断及随访

目的 探讨未通过听力筛查的新生儿和婴幼儿的听力变化及其特点,为听力评估及临床诊断和随访工作提供参考,为早期诊断,早期干预提供较为科学的依据.方法 2003年9月至2009年11月由我省各地州市接受了出生后初筛或复筛2次或2次以上听力筛查双耳或单耳未通过,转诊到我听力中心进行听力诊断性检查的婴幼儿143例,最终以听性脑干反应(auditory brainstem response,ABR)、40 Hz听觉相关电位(40 Hz auditory event related potentials,40 Hz-AERP)、畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)、声导抗结果进行评估和确认.对确诊为双耳重度和极重度听力损失的婴幼儿填写聋人调查表,进行跟踪随访,提出早期干预方案.结果 143例婴幼儿中确认听力损失者110例,占76.92%.其中单耳72例,占65.45%,双耳38例,占34.55%.听力损失中轻度31例,占28.18%;中度27例,占24.55%;重度27例,占24.55%;极重度25例,占22.72%.110例听力异常者有14例复查,占12.73%.复查者中双耳听力损失6例,单耳听力损失8例.14例双耳重度、极重度耳聋患儿,有10例配戴助听器,这些患儿正在接受语言康复训练.结论 耳声发射和听性脑干反应联合应用于新生儿及婴幼儿听力筛查,能提高其听力筛查的精确性和可靠性,对未通过听力筛查的婴幼儿,有必要在出生后3个月左右接受听性脑干反应和40 Hz听觉相关电位检查,以确保较为科学而可行的早期诊断、早期干预.本组听力异常患儿复查率低和失访率高仍是目前亟待解决的问题.     

GJB2基因听力学表型与基因型关系分析

目的分析GJB2基因的听力学表型与基因型关系。方法 2007年4月²011年3月在解放军总医院就诊的具有完整听力学资料的1481名非综合征性耳聋患者,均进行GJB2编码区测序,并对其GJB2基因突变检出阳性率及与听力学表型关系进行统计学分析。结果 1481例患者GJB2基因阳性突变率为20.05%,双耳感音神经性聋组阳性突变率为20.66%,高于单耳耳聋组(2.08%)(P<0.01)。在双耳感音神经性聋组中,极重度聋组中的GJB2阳性检出率最高(26.07%),其次是重度(18.12%)、中度(17.4%),轻度组为11.54%,各组间阳性检出率差异有统计学意义(P<0.01)。对297例GJB2基因突变阳性患者听力曲线分型分析中,发现了10例上升型听力曲线(14.93%),但GJB2耳聋听力图仍以残余型(26.27%)、平坦型(25.16%)常见,各组阳性检出率差异有统计学意义(P<0.01)。结论 GJB2基因突变者听力学表型呈多样性,在进行基因检测时,除重视双耳重度、极重度感音神经性聋或听力图为残余型和平坦型的人群外,也应该对单耳耳聋、双耳轻度听力损失或听力图为上升型感音神经性聋患者进行常规耳聋基因检测。     

助听器干预对西藏高原地区听障患者的疗效分析

目的 探讨助听器干预对久居(超过40年)西藏高原地区听障患者的疗效情况。方法 选取49例(63耳)助听器佩戴者进行分析，包括听力情况、听阈、助听器后言语及助听器效果国际问卷主观感受相关分析等，并对助听器补偿效果进行了综合评价。结果 63耳中，中度听力损失34耳，重度听力损失25耳，极重度听力损失4耳。其中单耳35例，问卷平均得分(20.34±4.39)分；双耳14例，问卷平均得分(27.07±4.16)分；双耳得分高于单耳分数。助听言语分辨率与问卷主观评估呈正相关(r=0.528,P<0.01)。助听阈值显示大多数患耳未得到最佳的听力补偿，但助听器干预前后听力比较具有统计学意义(P<0.05),高频听力补偿更为明显。助听后言语测听显示，助听后言语最大分辨率较助听前高(P<0.05)。结论 高原地区听障者对助听器的使用客观听力参数与主观评价相对一致，助听效果较为显著而且双耳验配较单耳验配更具优势，总体助听效果持肯定态度。     

听力筛查未通过婴幼儿听力评估及转归

目的探讨烟台地区听力筛查未通过婴幼儿的听力学特点及其转归。方法回顾性分析烟台地区2011年12月至2013年12月听力筛查未通过进行听力学诊断的264例婴幼儿病例资料,男150例,女114例,初诊年龄为3个月~3岁,平均为4.4月龄,所有未通过听筛婴幼儿均进行了听性脑干反应、听性稳态反应、畸变产物耳声发射及鼓室导抗图测试等检查。结果 264例听力筛查不通过婴幼儿中102例(38.64%)双耳听力正常,听力损失总耳数为257耳(48.67%257/528),其中单耳听力损失67例(25.38%,67/264),双耳听力损失95例(35.98%,95/264);感音神经性听力损失137耳(25.95%,137/528)传导性听力损失或混合性听力损失120耳(22.73%,120/528);264例婴幼儿中ABR波V反应阈正常271耳(51.33%,271/528);轻度听力损失120耳(22.73%,120/528);中度听力损失75耳(14.21%,75/528);重度听力损失19耳(3.60%,19/528);极重度听力损失43耳(8.15%,43/528)。诊断小耳畸形4例(4耳,1.51%,4/528),诊断大前庭水管综合征(large vestibular aqueduct syndrome,LVAS)患儿6例(12耳,2.27%,12/528),其中5例发现短潜伏期负反应波。结论本组听力筛查转诊婴幼儿中听力损失检出率为61.36%,6个月以下轻中度听力损失的婴幼儿,由于中耳因素及听觉系统发育不断完善,随着月龄增加听力损失有好转趋势;因此对婴幼儿的听力评估需要结合多种检测方法并进行必要的跟踪随访。     

Vocalizations of infants with hearing loss compared with infants with normal hearing: Part I--phonetic development

OBJECTIVE: Infants with hearing loss are known to be slower to develop spoken vocabulary than peers with normal hearing. Previous research demonstrates that they differ from normal-hearing children in several aspects of prelinguistic vocal development. Less is known about the vocalizations of early-identified infants with access to current hearing technologies. This longitudinal study documents changes in prelinguistic vocalizations in early-identified infants with varying degrees of hearing loss, compared with a group of infants with normal hearing. It was hypothesized that infants with hearing loss would demonstrate phonetic delays and that selected aspects of phonetic learning may be differentially affected by restricted auditory access. DESIGN: The vocalizations and early verbalizations of 21 infants with normal hearing and 12 early-identified infants with hearing loss were compared over a period of 14 mo (from 10 to 24 mo of age). Thirty-minute mother-child interaction sessions were video recorded at 6- to 8-wk intervals in a laboratory playroom setting. Syllable complexity changes and consonantal development were quantified from vocalizations and early verbalizations. Early behaviors were related to speech production measures at 36 mo of age. Participants with hearing loss were recruited from local audiology clinics and early intervention programs. Participants with normal hearing were recruited through day care centers and pediatrician offices. RESULTS: Relative to age-matched, normal-hearing peers, children with hearing loss were delayed in the onset of consistent canonical babble. However, certain children with moderately-severe losses babbled on time, and infants with cochlear implants babbled within 2 to 6 mo of implantation. The infants with hearing loss had smaller consonantal inventories and were slower to increase syllable shape complexity than age-matched normal-hearing peers. The overall pattern of results suggested that consonant development in infants with hearing loss was delayed but not qualitatively different from children with normal hearing. Delays appeared to be less pronounced than suggested by previous research. However, fricative/affricate development progressed slowly in infants with hearing loss and divergence from the patterns of normal-hearing children was observed. Six children (2 with normal hearing; 4 with hearing loss) were identified as atypical, based on their rates of development. At 24 mo of age, these children persisted in producing a high proportion (0.59) of vocalizations lacking consonants, which was negatively correlated with Goldman-Fristoe scores at 36 mo (r = -0.60). CONCLUSIONS: Results suggest that early-identified children are delayed in consonant and syllable structure development, which may influence early word learning rates. Fricative/affricate development appears to be challenging for some infants with hearing loss. This may be related to the effects of sensorineural hearing loss on high-frequency information, restricted bandwidth provided by amplification, and reduced audibility in contexts of noise and reverberation. Delayed fricative use may have implications for morphological development. Atypically slow rates of change in syllable development may indicate that a child is at risk for delayed speech development.     

Auditory System Dysfunction due to Infantile Thiamine Deficiency: Long-Term Auditory Sequelae

Eleven infants who were fed a thiamine-deficient formula for a mean of 3 months were evaluated for immediate and long-term auditory abnormalities. At presentation, 8 infants had auditory neuropathy spectrum disorder (ANSD), which resolved with supplementary thiamine in 5 children, was permanent in 2 children, and deteriorated in 1 patient who died at the age of 7 years. An additional patient had an auditory pattern corresponding to that of auditory neuropathy of brain stem origin. The 2 remaining patients had unilateral cochlear hearing loss. Six to 8 years later, all patients with transient ANSD had normal audiograms, 2 patients had unilateral cochlear hearing loss, and the rest had neural hearing loss. All survivors had a language developmental delay and impaired speech intelligibility of varying degrees, especially in the presence of background noise. Thiamine is crucial for normal auditory development and function, and its deficiency may be considered an acquired metabolic cause of ANSD in infants.     

The New York State universal newborn hearing screening demonstration project: ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention

OBJECTIVE: To determine the ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention through a multi-center, state-wide universal newborn hearing screening project. DESIGN: Universal newborn hearing screening was conducted at eight hospitals across New York State. All infants who did not bilaterally pass hearing screening before discharge were recalled for outpatient retesting. Inpatient screening and outpatient rescreening were done with transient evoked otoacoustic emissions and/or auditory brain stem response testing. Diagnostic testing was performed with age appropriate tests, auditory brain stem response and/or visual reinforcement audiometry. Infants diagnosed with permanent hearing loss were considered for hearing aids and early intervention. Ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention were investigated regarding nursery type, risk status, unilateral versus bilateral hearing loss, loss type, loss severity, and state regions. RESULTS: The prevalence of infants diagnosed with permanent hearing loss was 2.0/1000 (85 of 43,311). Of the 85 infants with hearing loss, 61% were from neonatal intensive care units (NICUs) and 67% were at risk for hearing loss. Of the 36 infants fitted with hearing aids, 58% were from NICUs and 78% were at risk for hearing loss. The median age at identification and enrollment in early intervention was 3 mo. Median age at hearing aid fitting was 7.5 mo. Median ages at identification were less for infants from the well-baby nurseries (WBNs) than for the NICU infants and for infants with severe/profound than for infants with mild/moderate hearing loss, but were similar for not-at-risk and at-risk infants. Median ages at hearing aid fitting were less for well babies than for NICU infants, for not-at-risk infants than for at-risk infants, and for infants with severe/ profound hearing loss than for infants with mild/ moderate hearing loss. However, median ages at early intervention enrollment were similar for nursery types, risk status, and severity of hearing loss. CONCLUSIONS: Early ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention can be achieved for infants from NICUs and WBNs and for infants at risk and not at risk for hearing loss in a large multi-center universal newborn hearing screening program.     

ABR hearing screening for high-risk infants.

OBJECTIVE: The goals of this investigation were to determine the outcome of a high-risk newborn auditory brainstem response hearing screening program at this institution and to determine the clinical characteristics of the target population with special emphasis on the relationship between risk criteria and hearing status. STUDY DESIGN: This study involved the prospective screening of newborns with risk indicators and a retrospective analysis of results accumulated over a 10-year period. SETTING: The study was conducted either in the newborn nursery or outpatient audiology clinic of a tertiary health care center. PATIENTS: Patients were 2,103 newborns presenting with one or more risk indicators for significant congenital hearing loss or delayed onset/progressive sensorineural hearing loss. INTERVENTIONS: Diagnostic interventions involved auditory brainstem response screening at two intensity levels (25 dB and 65 to 75 dBnHL). MAIN OUTCOME MEASURES: The main outcome measure was incidence of significant, nonmedically treatable hearing loss in this population. A secondary outcome measure was determination of incidence of hearing loss in association with different risk indicators. RESULTS: One hundred fourteen (5.4%) infants were diagnosed with bilateral hearing loss. Twenty-three infants (1%) presented with unilateral hearing loss. Sixty seven (49%) of the 137 infants diagnosed with hearing loss presented with greater than moderate hearing loss. Nine (13.4%) of these 67 patients presented with delayed onset hearing loss that was diagnosed at appointments subsequent to the initial screening. The largest percentage of diagnosed hearing loss was found in the "craniofacial anomalies" category. CONCLUSIONS: Auditory brainstem response hearing screening of newborns at risk for significant hearing loss is a clinically efficient and cost effective approach to early detection of significant hearing loss. For this program, the calculated cost to diagnose one hearing impaired infant from this population is $3000.     

Problems in the evaluation of hearing of infants

Infant hearing loss should be identified early to prevent delays in the development of speech and language. However, evaluation of hearing of infants is not so easy, because training is required to estimate auidiometric thresholds from behavioral testing such as conditioned orientation response audiometry (COR). Most ENT physicians who are not capable of behavioral testing tend to evaluate hearing of infants only from testing auditory brainstem response (ABR). Information about the infant's auditory response to the environmental sounds could be obtained easily and might be a substitute for a behavioral testing. We administered a questionnaire to the parents to obtain accurate information about the infant's auditory response. Tanaka-Shindo's developmental battery test of auditory function is an established questionnaire with various questions about auditory response and development of speech according to the age of infants from 0-15 month. We administered Tanaka-Shindo's questionnaire to the parents of infants before 8 months, and administered the following questionnaire to the parents of infants over 8 months. (1) If you call out the child's name from behind, does the child turn his/her head? (2) Does the child turn his/her head to any sounds on television, to any small sounds (for example: listened when someone opens the door or opens wrapping paper), or to beeping sounds from electric devices? To investigate the clinical usefulness of the questionnaire to estimate hearing in infants, 79 children (under 4 y.o.) evaluated their hearing at the Tottori University Hospital were studied. Forty-three out of 45 (95.6%) who had normal hearing had yes in the questionnaire, but the 18 who had moderate to severe (60 dB) hearing loss did not have yes in the questionnaire. For the mentally retarded 33 children, 27 out of 29 (93%) who had normal hearing had yes in the questionnaire, but the 4 who had moderate to severe hearing loss did not have yes in the questionnaire. Questionnaire about the infant's auditory response is useful to differentiate between normal hearing and moderate to severe hearing loss. We recommend our questionnaire as screening procedure to most ENT physicians to identify hearing loss in infants. It is important refer patients not evaluated as normal to an ENT physician who is capable of diagnosing the hearing of infants by behavioral testing.     

新生儿普遍听力筛查假阴性分析

目的 探讨耳声发射作为新生儿普遍听力筛查方法的可靠性及出现假阴性的原因，说明对高危儿进行听力监测的重要性。方法 收集2002年1月～2005年12月参加上海市新生儿听力筛查，并在上海儿童医学中心听力障碍诊治中心确诊为听力障碍者的资料，报道分析5例通过新生儿听力筛查、而在6～30月龄期间在该中心诊断为听力障碍者的病史、临床表现、听力学及影像学检查的结果。结果 通过新生儿听力筛查但被确诊为听力障碍者共5例，2例确诊为中重度感音神经性聋，3例确诊为极重度感音神经性聋，其中1例确诊为听神经病。耳声发射作为新生儿听力筛查方法，灵敏度是99．88％，假阴性率是0．12％。结论 耳声发射是灵敏度较高的新生儿听力筛查方法，但是有一定的假阴性率，对于各种原因造成的蜗后听觉通路病变所致的耳聋可能会漏诊。另外，对新生儿听力筛查阴性者，要警惕遗传性聋和迟发性聋的发生，尤其对高危儿应该定期随访。     

An initial overestimation of sensorineural hearing loss in NICU infants after failure on neonatal hearing screening

Objective

Infants admitted to neonatal intensive care units have a higher incidence of significant congenital hearing loss. We classified audiologic diagnoses and follow-up in infants who had been admitted to our neonatal intensive care unit.

Methods

We included all infants admitted to the neonatal intensive care unit at Sophia Children's Hospital between 2004 and 2009 who had been referred for auditory brainstem response measurement after failing neonatal hearing screening with automated auditory brainstem response. We retrospectively analyzed the results of auditory brainstem response measurement.

Results

Between 2004 and 2009 3316 infants admitted to our neonatal intensive care unit had neonatal hearing screening. 103 infants failed neonatal hearing screening: 46 girls and 57 boys. After first auditory brainstem response measurement we found 18% had normal hearing or a minimal hearing loss. The remainder had a type of hearing loss, distributed as follows: 15% conductive, 32% symmetric sensorineural, 14% asymmetric sensorineural, and 21% absent auditory brainstem responses. Repeated auditory brainstem response measurement showed a shift in hearing outcome. The main difference was an improvement from symmetric sensorineural hearing loss to normal hearing. However, in a small percentage of children, the hearing deteriorated.

Conclusions

As many as 58% of infants in this high-risk population who failed the neonatal hearing screening were diagnosed with sensorineural hearing loss or absent auditory brainstem responses. An initial overestimation of sensorineural hearing loss of about 10% was seen at first auditory brainstem response measurement. This may be partially explained by a conductive component that has resolved. Finally, in a small percentage of children the hearing deteriorated.     

Auditory neuropathy/auditory dys-synchrony detected by universal newborn hearing screening

The implementation of neonatal hearing screening has enabled early detection and intervention in hearing loss. The use of otoacoustic emissions (OAE) and auditory brainstem response testing in universal screening has led to the recognition of this recently described disorder called auditory neuropathy/auditory dys-synchrony (AN/AD). This diagnosis indicates that the infant has significant hearing loss despite having normal outer hair cells in the cochlea. We reviewed the characteristics and natural history of nine infants detected to have AN/AD from universal newborn hearing screening in a national pediatric hospital. Fifty-two cases of hearing loss were detected from 14,807 consecutively screened cases. Of the 52 cases, 9 had electrophysiological test results consistent with AN/AD. They include both premature infants who had major neonatal complications and term infants with no perinatal complications. Six cases had bilateral and three cases had unilateral findings. We suggest that AN/AD can occur in low-risk infants and hence screening of high-risk cases alone is insufficient. Our findings are discussed with reference to the current literature.     

Vocalizations of infants with hearing loss compared with infants with normal hearing: Part II--transition to words

OBJECTIVE: By 24 mo of age, most typically developing infants with normal hearing successfully transition to the production of words that can be understood about 50% of the time. This study compares early phonological development in children with and without hearing loss to gain a clearer understanding of the effects of hearing loss in early-identified children. A secondary goal was to identify measures of early phonetic development that are predictors of later speech production outcomes. DESIGN: The vocalizations and early words of 21 infants with normal hearing and 12 early-identified infants with hearing loss were followed longitudinally over a period of 14 mo (from 10 to 24 mo of age). Thirty-minute mother-child interaction samples were video recorded at 6- to 8-wk intervals in a laboratory playroom setting. Vocalizations produced at 16 and 24 mo were categorized according to communicative intent and recognizable words versus other types. Groups were compared on the structural complexity of words produced at 24 mo of age. Parent report measures of vocabulary development were collected from 10 to 30 mo of age, and Goldman-Fristoe Test of Articulation scores at 36 mo were used in regression analyses. RESULTS: Both groups increased the purposeful use of voice between 16 and 24 mo of age. However, at 24 mo of age, the toddlers with hearing loss produced significantly fewer words that could be recognized by their mothers. Their samples were dominated by unintelligible communicative attempts at this age. In contrast, the samples from normal hearing children were dominated by words and phrases. At 24 mo of age, toddlers with normal hearing were more advanced than those with hearing loss on seven measures of the structural complexity of words. The children with normal hearing attempted more complex words and productions were more accurate than those of children with hearing loss. At 10 to 16 mo of age, the groups did not differ significantly on parent-report measures of receptive vocabulary. However, the hearing loss group was much slower to develop expressive vocabulary and demonstrated larger individual differences than the normal hearing group. Six children identified as atypical differed from all other children in vowel accuracy and complexity of word attempts. However, both atypical infants and typical infants with hearing loss were significantly less accurate than normal hearing infants in consonant and word production. Early measures of syllable production predicted unique variance in later speech production and vocabulary outcomes. CONCLUSIONS: The transition from babble to words in infants with hearing loss appears to be delayed but parallel to that of infants with normal hearing. These delays appear to exert significant influences on expressive vocabulary development. Parents may appreciate knowing that some children with hearing loss may develop early vocabulary at a slower rate than children with normal hearing. Clinicians should monitor landmarks from babble onset through transitions to words. Indicators of atypical development were delayed and/or limited use of syllables with consonants, vowel errors and limited production of recognizable words.