Early Diagnosis Of Hearing Loss Research Articles

Audiological practices and findings post HPCSA position statement: Assessment of children aged 0 - 35 months

Background. Early detection of hearing loss is important to ensure optimal development, and may be influenced by the audiological assessment process. Objective. To describe the actual practices and audiological findings with regard to the assessment of 0 - 35-month-old children referred for a hearing assessment at a public hospital. Methods. A retrospective record review was conducted. The study sample comprised 100 participant files. Results. The mean age of initial hearing screening was 13.1 months. Of the participants, 99% received an initial hearing screening and 44% received a second hearing screening. Only four of the eight participants who were referred underwent auditory brainstem response testing and were diagnosed with hearing loss. These four participants were diagnosed after the age of 2 years. The audiological protocol differed from that recommended by the Health Professions Council of South Africa, resulting in limited diagnostic assessment results. Conclusion. The study highlighted gaps in the practice of recommended, age-appropriate audiological protocols as well as the ages at which the initial hearing screenings were conducted, which affects early diagnosis of hearing loss.

Early diagnosis of hearing loss: otoacoustic emissions evoked by distortion products and pure-tone audiometry: Preliminary findings.

Literary studies underline the effectiveness of distortion product otoacoustic emissions (DPOAEs), which are not affected by the collaboration of the subject examined, in the early diagnosis of hearing loss. Aim of the study is to compare the objective technique of DPOAEs with respect to the pure-tone audiometry in early diagnosis of hearing loss. The clinical research was carried out on 852 workers. All subjects underwent pure-tone audiometry, tympanometry and distortion products. The results show: a) a prevalence of subjects with impaired DPOAEs higher than the prevalence of subjects with impaired audiometries in the studied samples; and, after division by gender: b) a prevalence of subjects with impaired DPOAEs higher than the prevalence of subjects with impaired audiometries only in men; c) a prevalence of impaired DPOAEs and of impaired audiometries in men higher than in women. The results suggest the higher effectiveness of DPOAEs compared to pure-tone audiometry in making an early diagnosis of hearing loss.

Characterization of hearing thresholds from 500 to 16,000 hz in dentists: a comparative study.

Introduction High-level noise exposure in dentists' workplaces may cause damages to the auditory systems. High-frequency audiometry is an important tool in the investigation in the early diagnosis of hearing loss. Objectives To analyze the auditory thresholds at frequencies from 500 to 16,000 Hz of dentists in the city of Curitiba. Methods This historic cohort study retrospectively tested hearing thresholds from 500 to 16,000 Hz with a group of dentists from Curitiba, in the state of Paraná, Brazil. Eighty subjects participated in the study, separated into a dentist group and a control group, with the same age range and gender across groups but with no history of occupational exposure to high levels of sound pressure in the control group. Subjects were tested with conventional audiometry and high-frequency audiometry and answered a questionnaire about exposure to noise. Results Results showed that 81% of dentists did not receive any information regarding noise at university; 6 (15%) dentists had sensorineural hearing impairment; significant differences were observed between the groups only at frequencies of 500 Hz and 1,000, 6,000 and 8,000 Hz in the right ear. There was no significant difference between the groups after analysis of mean hearing thresholds of high frequencies with the average hearing thresholds in conventional frequencies; subjects who had been working as dentists for longer than 10 years had worse tonal hearing thresholds at high frequencies. Conclusions In this study, we observed that dentists are at risk for the development of sensorineural hearing loss especially after 10 years of service.

Analysis of the clinical audiological characteristics in 92 Chinese Alport syndrome cases

To analyze the clinical audiological characteristics in Chinese Alport syndrome, and investigate the relationship between the genotypes of Alport syndrome and hearing phenotype. The clinical hearing data of 92 cases diagnosed as Alport syndrome from 2008 August to 2013 August were reviewed and analyzed. All coding exons of COL4A3 and COL4A5 genes were PCR-amplified and sequenced from genomic DNA, or mRNA of COL4A5 gene was RT-PCR-amplified and sequenced from skin fibroblast in 17 cases. Eighty-seven out of 92 cases were found with X-linked dominant inheritance (XLAS); 5 cases with autosomal recessive (ARAS); 44 cases had normal hearing, but 14 young cases had abnormal OAE; 48 cases (52.2%, 35 male, 13 female) had sensorineural hearing loss. A total of 44 cases with XLAS had hearing loss (49.4%), wherein the incidence of hearing impairment was 55.0% in male XLAS, and 37.0% in female XLAS. Mild and moderate hearing loss were found in XLAS. Audiometric curves including groove type (21 cases), descending type (13 cases), flat type (10 cases), high frequency drop type (3 cases) and ascending type (1 case) were found in AS. Sixteen mutations of COL4A3, COL4A5 gene were found in 17 cases with Alport syndrome, including severe mutation in 8 cases with moderate hearing impairment. Mild and moderate hearing impairment, and groove type of audiometric curve are mainly found in Chinese Alport syndrome, which is different from Alport syndrome in western countries. OAE in the early diagnosis of hearing loss is important. Hearing phenotype is related certainly with genotype.

Profile of patients assessed for cochlear implants

IntroductionKnowledge of the characteristics related to profound hearing loss is a matter of great importance, as it allows for the etiological and prognostic identification and strategic planning for public health interventions. ObjectiveTo assess the different etiologies of hearing loss, age at diagnosis of the hearing loss, its relation to language acquisition, and the age at the first consultation in this service for cochlear implant assessment. MethodsThis was a historical cohort, cross-sectional study, using retrospective analysis of the records of 115 patients with confirmed sensorineural hearing loss, who were followed in a university hospital, based on gender, age of hearing loss, age at the first consultation, language, and hearing loss etiology. Results and conclusionThe majority of patients assessed for cochlear implants attend the first consultation when they are older than one year (an alarming mean of 3.8 years in the prelingual group) in spite of the early diagnosis of hearing loss. This reflects an already deficient health care system, in terms of referral. The idiopathic cause remains the most frequently identified. Among the known causes, the most prevalent are perinatal causes and meningitis.

Reabilitação auditiva na criança: adesão ao tratamento e ao uso do aparelho de amplificação sonora individual

OBJETIVO: Discutir a adesão das famílias na fase inicial de intervenção quanto ao uso do Aparelho de Amplificação Sonora (AASI), a participação no processo, e sua relação com desempenho auditivo e de linguagem das crianças com deficiência auditiva. MÉTODOS: Estudo realizado com pais e/ou responsáveis de 16 crianças deficientes auditivas em processo de ADAPTI (Adaptação de AASI e Terapia Inicial) no ano de 2009 e que estavam regularmente inscritas no Serviço de Saúde Auditiva Centro Audição na Criança - CeAC. Os pais foram divididos em três grupos: Pré-determinado - PD (famílias participantes da terapia fonoaudiológica e do Grupo de Adesão Familiar - GrAF, do primeiro ao último dia de atendimento estabelecido); Fluxo contínuo - FC (famílias que iniciavam a participação no GrAF a partir do momento em que chegavam ao serviço de saúde para a adaptação de AASI, sem início estabelecido) e Controle - C (famílias que participaram somente da terapia fonoaudiológica, mas não do GrAF). RESULTADOS: Foi constatada a efetividade da adesão dos pais ao tratamento dos filhos, sendo registrado o comparecimento em mais de 66% dos atendimentos propostos (terapia fonoaudiológica e/ou GrAF). Na análise estatística dos agrupamentos de crianças, foi possível a formação de três diferentes grupos no que se refere ao uso do datalog (horas/dia), envolvimento familiar e grau de perda auditiva. CONCLUSÃO: O uso sistemático de AASI foi a única variável com forte relação com habilidades auditivas e de linguagem. O grau de perda auditiva e a idade de início de amplificação não explicaram o desenvolvimento das crianças do estudo.

Prevalence of hearing loss in newborns admitted to neonatal intensive care unit.

Hearing is essential for humans to communicate with one another. Early diagnosis of hearing loss and intervention in neonates and infants can reduce developmental problems. The aim of the present study was to assess the prevalence of hearing impairment in newborns admitted to a neonatal intensive care unit (NICU) and analyze the associated risk factors. This cross-sectional study was conducted to assess the prevalence of hearing loss in neonates who were admitted to the NICU at Nemazee Hospital, Shiraz University of Medical Sciences between January 2006 and January 2007. Auditory function was examined using otoacoustic emission (OAE) followed by auditory brainstem response (ABR) tests. Relevant potential risk factors were considered and neonates with a family history of hearing loss and craniofacial abnormality were excluded. For statistical analysis logistic regression, the chi-squared test, and Fisher's exact test were used. Among the 124 neonates included in the study, 17 (13.7%) showed hearing loss in the short term. There was a significant statistical relationship between gestational age of less than 36 weeks (P=0.013), antibiotic therapy (P= 0.033), oxygen therapy (P=0.04), and hearing loss. On the contrary, there was no significant relationship between hearing loss and use of a ventilator, or the presence of sepsis, hyperbilirubinemia, congenial heart disease, transient tachypnea of newborn, congenital pneumonia, or respiratory distress syndrome. Auditory function in neonates who are admitted to a NICU, especially those treated with oxygen or antibiotics and those born prematurely, should be assessed during their stay in hospital. The importance of early diagnosis of hearing loss and intervention in these neonates and avoidance of any unnecessary oxygen or antibiotic therapy needs to be further promoted.

Analysis of the variability of auditory brainstem response components through linear regression

The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analyzing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. In this context, the aim of this research is to compare ABR manual/visual analysis provided by different examiners. Methods: The ABR data were collected from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). A total of 160 data samples were analyzed and a pair- wise comparison between four distinct examiners was executed. We carried out a statistical study aiming to identify significant differences between assessments provided by the examiners. For this, we used Linear Regression in conjunction with Bootstrap, as a method for evaluating the relation between the responses given by the examiners. Results: The analysis suggests agreement among examiners however reveals differences between assessments of the variability of the waves. We quantified the magnitude of the obtained wave latency differences and 18% of the investigated waves presented substantial differences (large and moderate) and of these 3.79% were considered not acceptable for the clinical practice. Conclusions: Our results characterize the variability of the manual analysis of ABR data and the necessity of establishing unified standards and protocols for the analysis of these data. These results may also contribute to the validation and development of automatic systems that are employed in the early diagnosis of hearing loss.

Neurological features of infants hearing and early diagnosis of hearing loss

婴幼儿听力的神经学特征 神经科学研究揭示［1］：真实世界中的事件由人类的听觉、视觉和躯体感觉等多模式偶联，同步作用于大脑，才能产生完整的反应。先天性听力损失因听觉被剥夺，听觉系统与其他系统解偶联，大脑听区会被视觉和其他感觉取代，这种神经重组将减少听觉性能并影响大脑认知和语言功能的发育

For Children With Hearing Loss: The Times They Are A-changin’

Today, children with hearing loss have more opportunities than ever before to use audition and to achieve age-appropriate spoken language and academic outcomes. Several factors are driving these new outcomes, including universal newborn hearing screening and earlier diagnosis of hearing loss, immediate fitting of advanced hearing technology, and enrollment in appropriate early intervention services. For speech-language pathologists and audiologists, these changes mean altering how these children and their families are served, including the types of diagnostic evaluations that are conducted. Specifically, if speech-language pathologists are to remain vital service providers, they must raise their professional expectations for what these children can ultimately achieve.

Screening, diagnosing and treating deafness: the knowledge and conduct of doctors serving in neonatology and/or pediatrics in a tertiary teaching hospital.

Infant hearing deficiency is a human disorder with devastating effects and serious implications for the development of speech and language. Early diagnosis of hearing loss should be the objective of a multidisciplinary team, and early-intervention programs should immediately follow this. The aim of this study was to investigate the knowledge and conduct of pediatricians and pediatric residents in a tertiary teaching hospital regarding deafness. Cross-sectional study in a tertiary hospital in the state of São Paulo, Brazil. Eighty-eight questionnaires were randomly distributed to pediatricians and pediatric residents. Thirty-six questionnaires were analyzed. Most respondents (61.1%) were residents in pediatrics and/or neonatology. Eighty-three percent of them performed special procedures on babies presenting a high risk of deafness, and 55% reported that they had no knowledge of techniques for screening hearing. Most of them were unaware of the classifications of level and type of hearing loss. According to 47.2% of them, infants could begin to use a hearing aid at six months of age. Most of them reported that infants could undergo hearing rehabilitation during the first six months of life, and all respondents stated 's responsibilities. Even though most of the participants followed special procedures with babies presenting a high risk of deafness, they did not routinely investigate hearing. All respondents believed that it is a doctor's responsibility to be concerned about child communication.

The roles of connexin genes in sporadic hearing loss population

To investigate the roles of connexin genes in Chinese population. Peripheral blood samples were collected from 214 patients with hearing loss, 160 with sensorineural hearing loss (66 with prelingual hearing loss and 94 with postlingual hearing loss), 32 with auditory neuropathy, and 22 with enlarged vestibular aqueduct syndrome (EVAS), 110 males and 104 females, all from 14 provinces north of the Yangtze River, all of Han nationality, and 86 normal controls. PCR and sequencing of the PCR products were used to screen 3 connexin genes: GJB2, GJB3, and GJB6. The frequency of connexin gene sequence variant was 73.36% (157/214), higher than that of the controls (60.05%, 42/86). 34 of the 157 patients carried pathogenic mutations (15.89%). The frequency of 235delC deletion was 16.67% among patients with prelingual hearing loss (11/66). Six known polymorphisms and six new mutations were found in these patients. The pathogenic mutations of the patients with hearing loss are distributed quite differently between the patients and normal persons. The genetic variants GJB2 235delG and GJB6-Delta (GJB6/D13S1830) were not common. Relevant information is helpful in early diagnosis of hearing loss in Chinese population.

Early diagnosis of hearing loss in newborns and children

An early diagnosis of the hearing loss in newborns and infants is very important for the early treatment and for the mental development of a child. The transient OAEs are the best methods for clinical applications in newborns' screening and also young children for a detection of hearing loss.In a present study, transient otoacustic emissions (TEOAEs) were obtained from 1622 newborns and 162 children (age from 6 months to 4 years). When TEOAEs were absent, the tympanometry was indicated for the excluded middle ear pathology. Approximately 1.5% of the newborns had the middle ear pathology. In 2 children out of 12, who suffered from glue ear, after the ventilation tube insertion, TEOAEs were absent and BERA confirmed the cochlear hearing loss. From 162 children, TEOAEs were absent in 47 and hearing loss was confirmed in all by the additional hearing tests. Only one child with presented TEOAE had the retrocochlear hearing loss confirmed by BERA.The otoacoustic emissions are useful as a screening method in newborns and children and also for the assessment of hearing after the ventilation tube insertion to exclude the cochlear hearing loss.

Early diagnosis of hearing loss

Early diagnosis of hearing loss

Hearing loss in speech-language delayed children

An infant begins to communicate with his/her environment from the first months of life. However, true words do not appear until the age of 12–15 months, following a rather predictable sequence. Delay or failure of normal language development is not a rare situation in childhood and may be due to a variety of reasons. Among these, hearing undoubtedly plays a leading part in the language acquisition process. The purpose of this study was to assess the percentage of hearing-impaired children in a group of phenotypically healthy children presenting with speech-language delay. Between March 1993 and March 1999, 726 speech-language delayed children were examined in our department. In 72 of them, various diseases or syndromes had already been diagnosed and so they were excluded from the study. The remaining 654 apparently healthy children entered the study and underwent a thorough audiological assessment for determination of their hearing thresholds. Eighty-seven children (13.3%) showed various degrees of hearing loss. Most of them (55 children, 8.4%) suffered from sensorineural hearing impairment, while in 32 children (4.9%) a conductive hearing loss was discovered. The increased prevalence of hearing impairment found in our population mandates a thorough hearing evaluation for every case of speech-language delay, even for those children who show no evidence of other handicaps. This will help in the early diagnosis of hearing loss, allowing proper management to be instituted as early as possible.

難聴児の早期発見と地域専門機関の現状について

難聴児の早期発見と地域専門機関の現状について

Clinical phenotype and mutations in connexin 26 (DFNB1/GJB2), the most common cause of childhood hearing loss

Mutations in the gene for connexin 26, GJB2, are the most common cause of hearing loss in American and European populations, with a carrier rate of about 3%-a rate similar to that for cystic fibrosis. A single mutation, 35delG, is responsible for most of this autosomal recessive hearing loss, DFNB1. A broad spectrum of mutations in GJB2 has been found to be associated with hearing loss, including another deletion mutation, 167delT, which has a carrier rate of about 4% in the Ashkenazi Jewish population. Mutations in GJB2 have also been found to be associated with dominant nonsyndromic hearing loss, DFNA3. Clinical studies have shown that the recessive hearing loss can vary from mild to profound, even within the same sibship. This type of hearing loss is nonsyndromic and is accompanied by normal vision, vestibular responses, and no malformations of the inner ear detectable by computed tomography scanning. Progressive and asymmetrical hearing loss has been noted in some cases, but it accounts for fewer than one-third of the cases of this type of hearing loss. The discovery of mutations in GJB2 that cause hearing loss has profound implications in the early diagnosis of hearing loss in general. The relative ease of diagnosis by genetic testing of Cx26 permits early identification of children with GJB2/DFNB1 hearing loss. This testing, coupled with hearing loss diagnosed by infant auditory brainstem response audiometry, will ensure that hearing-impaired children and their parents receive proper medical, audiologic, genetic, and educational counseling. Am. J. Med. Genet. (Semin. Med. Genet.) 89:130-136, 1999.

The audiologic assessment of the young pediatric patient: the clinic.

ue to the increasing number of newborn D hearing screening programs, infants are being referred for audiologic assessment and diagnosed with hearing loss at very young ages. Early diagnosis of hearing loss necessitates early initiation of habilitation including the fitting of amplification. Providing appropriate amplification is dependent on having a reliable definition of the child’s hearing loss. The assessment process is therefore tantamount to the habilitation and hearing aid fitting process. Unlike most adults whose hearing loss can be defined in one clinic visit, children often require repeated visits before the configuration and degree of hearing loss is defined. Audiologic assessment in children is often a challenging, time-intensive and ongoing process, particularly when assessing the very young infant. Infants and young children do not possess the breadth of responses that adults do, requiring modifications of behavioral audiologic techniques. In addition, there is sometimes the need for electrophysiologic tests to provide a baseline estimate of auditory function until complete behavioral audiologic findings can be obtained. However, complete behavioral audiologic information is not necessary before the hearing aid fitting and early intervention processes can begin. Valuable time should not be wasted waiting for complete information. Rather, the amplification process should be initiated with refinements and adjustments of the hearing aid fitting occurring as more and more precise information is obtained. Both behavioral and electrophysiologic tests are used in the audiologic assessment of the very young pediatric patient. Behavioral tests usually are thought of as subjective and the electrophysiologic reliance or non-reliance on patient participation, respectively. At very young ages, the electrophysiologic test findings often predominate in the decision making about the management of the child with a hearing loss, but for older children it is generally the behavioral audiologic finding: on which management decisions are made. These two types of tests, however, provide information on different aspects of the child’s auditory function, and cannot serve as perfect substitutes for each other. What follows are brief descriptions of the behavioral and electrophysiologic tests that are appropriate for the young pediatric patient. It should be highlighted that behavioral audiologic testing of the young child can yield reliable results if proper procedures are followed during the test session.

At-risk populations for hearing impairment in infants and young children

The epidemiologic patterns of childhood hearing loss are ill-defined. Patterns found in prospective observations of newborns in intensive care nurseries are quite different from the patterns apparent in retrospective studies of hearing-impaired children. High-risk registers, at least those prior to the 1990 reformulation, missed about half of children subsequently identified as having hearing loss. Items comprising high-risk registers carry unequal weight. Children with sensorineural hearing loss have a disproportionately increased occurrence of otitis media, with its conductive hearing loss. Sensorineural hearing loss can be progressive. Case-control studies of children with hearing loss are needed. Efforts for the early diagnosis of hearing loss in children must take into practical consideration the uncertainties of available epidemiologic data, and the clinical nuances.

Persistent Fetal Circulation

• Forty children who had persistent fetal circulation (PFC) were followed up for one to four years. At the most recent examination, 16 (40%) were normal, eight (20%) had neurosensory hearing loss, three (7.5%) were profoundly impaired, six (15.0%) had suspect or abnormal results of neurologic examinations exclusive of hearing loss, three (7.5%) had speech impairment and normal hearing, and one had a delay in motor development. The remaining three had clinically suspect speech. Neurosensory hearing loss correlated only with having a mother with insulin-dependent diabetes, hand-to-mouth facility on the Brazelton scale, and eight-month neurologic status. Earlier diagnosis of hearing loss may be facilitated by testing of neonatal auditory behavioral responses, neurologic status at eight months, and by attention to parental concern about abnormal speech development. Neonatal and infancy auditory screening are recommended in children who have PFC in the neonatal period. (AJDC1985;139:25-28)