Objective: To determine the feasibility of audiological screening in low-risk neonates, using Otoacoustic Emissions (OAEs), at various test times following birth. The achievability of a screening programme within the Midwife Obstetric Unit (MOU) 3-day assessment clinic at the Phola Park Community Health Centre (PPCHC) was deliberated. Participants: Two hundred and seventy two neonates were included in this study. Design: A prospective and longitudinal design was employed. Methods and Materials: Case history interviews, otoscopic examinations and Distortion Product Otoacoustic Emissions (DPOAEs) were carried out at two sessions. The initial session took place within 6 hours after birth and the second session at approximately 3 days after birth at the MOU 3-day assessment clinic. Data Analysis: Data was collected as “pass” and “refer” screening results, the number of births was compared to the number of participants at the two sessions. The number of “pass” and “refer” results per session were analysed and results per participant at the two sessions were compared to detect false-positives. The return for follow-up rate was considered. Results: Screening is possible within hours of birth but is more practical and efficient at the MOU 3-day assessment clinic. During the study, 260 neonates were born at PPCHC, 38.07% of these were screened at session 1 and a total of 268 newborns were screened at session 2. The pass rate was 16.16% at session 1 and 99.25% at session 2; rendering a false-positive rate of 82.10% at session 1. Time of birth relative to discharge, resources, environmental factors, noise levels, return for follow-up rate and referral rate have been identified as factors that may impact the practicability and efficiency of screening. Conclusion: Outcomes of the study highlight the importance of studying methodologies to ensure effective reach for hearing screening within the South African context. Based hereon, screening neonates immediately after birth is possible. However, it is recommended that screening forms part of the MOU 3-day assessment protocol to ensure that a higher number of neonates are reached when confounding factors such as vernix have plummeted; hence decreasing false- positives.

This review of scientific literature was performed in Brazillan and North American studies about the prevalence and assessment procedures of Infant Hearing Loss. Fourteen Brazilian articles and 12 American publications of prevalence between 2000 and 2012 were reviewed. The prvalence of infant hearing loss in Brazilian papers was between 0.2% and 10.2% and American papers from 0.22% to 3.61%. As or the procedures used for diagnosis there was a high similarity in the choice of methods.

Infant hearing screening (IHS) programs are not yet widespread in developing countries, such as South Africa. In order to ensure that the benefits of early hearing detection and intervention (EHDI) programs reach all infants, initial recommendations for the implementation of IHS programs in South Africa have been made by the Year 2002 Hearing Screening Position Statement by the Health Professions Council of South Africa. One of the platforms recommended for IHS in South Africa is the neonatal intensive care unit (NICU). South African NICU infants are at an increased risk for hearing loss, resultant of their high-risk birth histories, as well as the prevalence of context-specific environmental risk factors for hearing loss. There is currently a general scarcity of contextual data regarding the prevalence of risk indicators for hearing loss, and the prevalence of auditory impairment in the South African NICU population. The objective of this study was to describe an IHS program for NICU infants at a secondary hospital in Gauteng, South Africa. A quantitative descriptive research design was used to report on a cohort of 129 NICU infants followed up during a 29 month period. The objective of the study was achieved by describing the sample of infants in terms of the presence of specific risk indicators for hearing loss, the efficiency of the IHS program, and the incidence of auditory pathologies. Infants received their initial hearing screening as part of their medical and developmental follow-up visit at the hospital at three months of age. Routine rescreening visits were scheduled three monthly, whilst infants who failed the hearing screening were requested to return after three weeks for a follow-up. A data collection sheet was used to collect biographical information and risk indicators for hearing loss. Immittance measurements were recorded in the form of high-frequency and low-frequency tympanometry. Distortion product otoacoustic emissions (DPOAE) and automated auditory brainstem responses (AABR) were recorded, as well as diagnostic auditory brainstem responses (ABR) in cases where infants referred the screening protocol. Results revealed that environmental risk factors present in this sample included poor maternal education levels and prenatal HIV/AIDS exposure. At least 32% of mothers participating in this study did not complete high school. Prenatal HIV/AIDS exposure was present in at least 21% of the current sample of infants. The screening coverage rate fell short of the 95% benchmark set by the Joint Committee on Infant Hearing (JCIH, 2000). A 67% coverage rate was achieved with AABR screening, and an 88% coverage rate was achieved with DPOAE screening. 93% of infants had immittance screening performed on their initial visit to the IHS program. According to the Fisher’s two-sided exact test and the logistic regression procedure, high frequency tympanometry proved to be more effective than low frequency tympanometry, when assessing the middle ear functioning of infants younger than seven months when compared with DPOAE results. Normative pressure and admittance data was compiled for the use of high frequency tympanometry in NICU infants. Poor follow-up rates were recorded for both routine and non-routine visits, but are expected to improve over time. Furthermore, results indicated a high incidence of hearing impairment. Permanent congenital hearing loss was identified in 3% (n=4) of the sample. Half of these presented with sensorineural hearing loss, whilst the other half had auditory neuropathy. The incidence of auditory impairment is estimated to be 3.75% if the percentage of infants who did not return for follow-up is taken into account. A high incidence of middle ear pathology was recorded, with an incidence rate of 60.4%, including bilateral and unilateral middle ear pathology. The high prevalence of auditory impairment in South African NICU infants, and the lack of widespread IHS programs, indicates that many vulnerable infants are being the denied the benefits of early identification of and intervention for hearing loss. The implementation of widespread IHS programs in South Africa is therefore essential, in order to ensure that all South African infants receive the benefits of EHDI programs. / Dissertation (MCommunication Pathology)--University of Pretoria, 2007. / Speech-Language Pathology and Audiology / unrestricted

Apart from isolated programs in private and public health care sectors, South Africa has no existing systematic public infant hearing screening program at community level. As a result, early identification of hearing loss is certainly not being attained for the majority of infants in South Africa with far-reaching effects for individuals, families and society at large. Screening programs at primary health care immunization clinics have been proposed as an alternative to hospital-based programs in South Africa. The objective of this study was to evaluate the first systematic community-based infant hearing screening program in a developing South African community in the Western Cape. A combined descriptive and exploratory research methodology was followed incorporating aspects of a program evaluation design. The study was of a quantitative nature and the required data were collected by means of a questionnaire and OAE testing conducted by clinic nurses on subjects. A community-based universal infant hearing screening program initiated at eight primary health care clinics in the Cape Metropolitan area was evaluated over a 19-month research period. During this time 6227 infants who were candidates for screening attended their 6, 10 or 14-week immunization visit at the relevant clinic. Clinic nurses were trained as screening personnel. A two-stage distortion product otoacoustic emissions screening protocol was utilized. The target disorder for this study was bilateral permanent congenital and early onset hearing loss and infants referring the first screen were scheduled for a 4-week follow-up visit at the clinic. Diagnostic audiological and medical evaluations were scheduled at referral hospitals when indicated. The study evaluated the efficacy of the program based on coverage, referral and follow-up rates and diagnostic outcomes according to guidelines specified by the Health Professions Council of South Africa 2007 Position Statement. Overall coverage rate across the eight clinics was 32.4% with 2018 infants (aged 0- 14 weeks) screened. The mean age of the sample at first stage screen was 3.9 weeks of age and 13.5 weeks of age for first hospital visit. Overall first stage screen referral rate was 9.5% with 62 subjects (3%) referred for diagnostic services at hospital level after a follow-up screen. The average follow-up rate for rescreens at clinic level was 85.1% and for initial diagnostic assessments at hospital level it was 91.8%. Although minimal hearing loss was not the primary focus of the screening program the outcomes did include those subjects with fluctuating conductive hearing loss and permanent unilateral hearing loss. Prevalence rates were 4.5/1000 with significant hearing loss, including sensorineural (1.5/1000) and conductive (3/1000) losses, and 12.9/1000 for subjects with middle ear effusion.<p-> The community-based infant hearing screening program was valuable in attaining high follow-up return rates but reaching sufficient coverage may require dedicated screening personnel as opposed to existing nursing personnel. Furthermore, consideration of an alternative community-based platform such as midwife obstetric units may improve coverage and referral rates and prevalence of permanent congenital and early onset hearing loss. / Dissertation (MCommunication Pathology)--University of Pretoria, 2013. / Speech-Language Pathology and Audiology / Unrestricted

Newborn hearing screening has become an increasingly important element of neonatal care in developed countries whilst only a few fragmented screening programmes are evident in developing countries. The numerous socio-economic, cultural and healthcare barriers in developing contexts do not, however, negate or diminish the need to ensure optimal outcomes for infants with hearing loss through early identification and intervention programmes. South Africa has taken a first step toward addressing this need by publishing a Year 2002 Hearing Screening Position Statement that was produced by the Professional Board for Speech, Language and Hearing Professions of the Health Professions Council of South Africa. Interim recommendations are made toward universal newborn hearing screening programmes in three contexts: well-baby nurseries,; neonatal intensive care units (NICU) and Maternal and Child Health (MCH) clinics through their 6-week immunisation programmes. Although these clinics constitute an unfamiliar hearing screening context, they are essential platforms toward widespread screening of the majority of infants in South Africa. An urgent need therefore exists to ascertain the feasibility of hearing screening programmes at MCH 6-week immunisation clinics in order to guide the future implementation of widespread hearing screening services in South Africa. To attend to this need, an exploratory descriptive design that jointly implements quantitative and qualitative methods in a dominant-less-dominant model of triangulation was utilised to critically describe a screening programme conducted at two MCH clinics in Hammanskraal (a developing, peri-urban South African community). The quantitative methods included a structured interview to compile biographical and risk information; high frequency immittance measurements; hearing screening with OAE and AABR according to specified protocols, and diagnostic assessment of referred infants. The qualitative methods included field notes and critical reflections describing clinics as screening contexts and elucidating interactional processes involved in sustaining programmes. A total number of 510 infant-caregiver pairs were enrolled as subjects during the five-month research period. Results indicate that clinics not only provide a suitable context, but also the possibility of effective collaborations toward facilitating effective initial infant hearing screening programmes. The caregivers and infants who attended the clinics demonstrated significant degrees of socio-economic deprivation. They also reported an increased incidence of risk indicators exacerbating the population’s risk for congenital hearing loss, poor participation in the hearing screening/follow-up process, and subsequent poor involvement in a family-centred early intervention process for infants identified with hearing loss. The screening protocol effectively classified infants into risk categories for hearing loss and established useful norms for high frequency immittance in infants. The efficiency of the programme was acceptable considering the short period of implementation, but inefficient coverage with the AABR and poor follow-up return rates were obtained at the clinics. Despite prevailing barriers, the MCH 6-week immunisation clinics showed promise as platforms for widespread hearing screening programmes for infants in South Africa. The clinical implications and recommendations that emerged from the research conducted in this study were compiled and presented in the form of a preliminary service delivery model for infant hearing screening at MCH clinics. / Thesis (DPhil (Communication Pathology))--University of Pretoria, 2004. / Speech-Language Pathology and Audiology / unrestricted

Electrophysiological measures such as impedance telemetry and Neural Response Telemetry (NRT™) were developed by Cochlear™ in 1992 as clinical tools allowing the objective setting of stimulus levels for cochlear implant users. Extensive research proved the usefulness of NRT™’s as an aid in the programming process of audible and comfortable stimulus levels for children younger than six years. The Nucleus® Freedom™, launched in 2005, introduced new developments in cochlear implantation. Approval from the FDA for this system was obtained in March 2005 and for the first time included children from age 12 months with profound hearing loss. The Joint Committee on Infant Hearing suggested that children be diagnosed and that treatment commenced by the age of six months. The new features of the Nucleus Freedom™ give clinicians the necessary tools to treat this challenging population. An urgent need exists to ascertain the stability and accuracy of the new features introduced by this system, especially the Auto-NRT™ software, to validate its use within the paediatric population. A longitudinal descriptive design was utilized implementing quantitative research methods to critically describe the behaviour of impedance telemetry and NRT™’s in a group of young cochlear implant users. The quantitative method included the application of the Custom Sound™ software and the Auto-NRT™ feature for this group at implantation, device activation, and then at determined follow-up visits. Nine young children between nine months and five years and eleven months were used as participants during the twelve months of research. Impedance telemetry was described in terms of the mean Common Ground (CG) and Monopolar 1+2 (MP1+2) values calculated from measurement data collected on the basal, medial, and apical electrodes of the electrode array. The electrodes identified for statistical procedures for both measurement types were E3, E6, E8, E11, E13, E16, E19 and E21. Friedman’s ANOVA was used as a statistical measure to determine the level of significance in changes among the measurement modes and conditions. The Wilcoxon signed-rank test was indicated in the presence of significant changes identified by Friedman’s ANOVA to calculate the level of significance in a pair-wise comparison. Results indicate that impedance telemetry remained consistent over the electrode array and over time in both measurement modes. A slight increase in mean values was observed during the first three months, followed by a gradual decrease at the six months interval. These changes were statistically nonsignificant. No specific trends were evident in impedance telemetry over time. NRT™-measurements remained consistent across the electrode array over time. Significant changes were present between the intra-operative to device activation measurement intervals. This trend is also described in studies of adult cochlear implant users. NRT™-measurements were stable during the first year postimplantation within the paediatric population. A comparison between the mean impedance telemetry and NRT™’s disclosed an inverse trend during the first six months post-implantation. Most changes were non-significant, indicating that these measures can be used effectively in the new semi-automated fitting software. The implementation of these measurements can lead to streamlined and accountable service delivery to young cochlear implant users. AFRIKAANS : In 1992 is elektrofisiologiese metings soos impedanstelemetrie en Neurale Respons Telemetrie (NRT™) deur Cochlear™ ontwikkel as kliniese hulpmiddels om objektiewe instelling van stimulasievlakke vir kogleêre gebruikers moontlik te maak. Navorsing het bewys dat NRT™’s ‘n effektiewe hulpmiddel is tydens programmering van hoorbare en gemaklike stimulasievlakke by kinders jonger as ses jaar. Die Nucleus® Freedom™ met nuwe ontwikkelings ten opsigte van kogleêre inplantings is in 2005 bekendgestel. Die FDA het in Maart 2005 hierdie sisteem goedgekeur vir gebruik by kinders selfs so jonk as 12 maande met uitermatige gehoorverlies. Die Joint Committee on Infant Hearing het voorgestel dat diagnose en aanvang van rehabilitasie teen ses maande ouderdom moet plaasvind. Die nuwe funksies van die Nucleus® Freedom™ stel oudioloë in staat om hierdie uitdagende bevolking te hanteer. ‘n Dringende behoefte bestaan om te bepaal of hierdie sagteware, veral Auto-NRT™ wat saam met hierdie sisteem bekendgestel is, oor voldoende akkuraatheid en stabiliteit beskik om in die hantering van die pediatriese bevolking te gebruik. ‘n Longitudinale, beskrywende ontwerp, wat kwantitatiewe metodes implementeer, is aangewend om die beweging van impedanstelemetrie en NRT™’s by ‘n groep jong gebruikers van kogleêre inplantings krities te beskryf. Dit het die gebruik van die Custom Sound™ sagteware en die ingeslote Auto- NRT™ funksie behels. Dit is tydens inplantering, by aktivering van die toestel, en bepaalde opvolgsessies uitgevoer. Nege jong kinders tussen die ouderdomme van nege maande en vyf jaar en 11 maande is tydens die 12 maande navorsingsperiode as proefpersone benut. Die impedansmetings is beskryf in terme van die Common Ground (CG) en Monopolar 1+2 (MP1+2) stimulasiemodaliteite. Data is verkry vanaf geselekteerde elektrodes op die basale, mediale en apikale gedeeltes van die elektrode. Vir statistiese ontledings van impedans en NRT™ is hierdie elektrodes geselekteer: E3, E6, E8, E11, E13 E16, E19 en E21. As statistiese ontledingsmetode, is Friedman se ANOVA toegepas om die vlakke van beduidenheid van beweging tussen die verskillende toetsmodaliteite en -omstandighede te bepaal. Die Wilcoxon signed-rank toets is aangedui in die teenwoordigheid van statisties beduidende veranderinge. Die doel van hierdie toets was om die vlak van beduidenheid paarsgewys te verifieer. Resultate dui op konstante impedansmetings oor die elektrode asook oor tyd in beide toetsmodaliteite. ‘n Geringe, statisties nie-beduidende, verhoging in gemiddelde waardes is waargeneem tydens die eerste drie maande na inplantering, waarna die waardes weer geleidelik afgeneem het tot en met die ses maande opvolginterval. Geen spesifieke neiging kon vir impedanstelemetrie bepaal word nie. NRT™-metings het konstant gebly oor die elektrode en met tyd. Statisties beduidende veranderinge is gemeet tussen die intra-operatiewe en aktiveringsintervalle. Hierdie neiging is ook beskryf in studies van volwasse gebruikers van kogleêre inplantings. NRT™-metings, binne die pediatriese populasie, het dus stabiel gebly oor die 12 maande periode post-inplantering. ‘n Vergelyking tussen die gemiddelde impedans- en NRT™-metings het ‘n inverse neiging geïdentifiseer gedurende die eerste ses maande na inplantering. Veranderinge was oor die algemeen statisties nie-beduidend, wat daarop dui dat hierdie metings effektief gebruik kan word. Die implementering van hierdie metings kan meer doeltreffende dienslewering aan die jong gebruikers van kogleêre inplantings tot gevolg hê. / Dissertation (MCommunication Pathology)--University of Pretoria, 2010. / Speech-Language Pathology and Audiology / unrestricted