both the psychomotor and emotional development can be significantly impaired when the child has hearing problems .
lack of information and acoustical stimuli in the first years of life restricts or even disables the development of speech .
earlier diagnosis of hearing problems in an infant or child is enhances the possibility of choosing the proper diagnostic and therapeutic path .
timely intervention is an important component of any early hearing detection and intervention ( ehdi ) screening program .
the first neonatal screening programs ( nhs ) in poland were designed in the 1980s and subsequent studies took place in the mid-1990s .
the results of the polish nhs / edhi program suggest that the incidence of congenital hearing disorders ranges from 2 to 7 per 1000 births , estimates which have been verified by other studies in the literature [ 611 ] .
a child might present a hearing loss caused by acquired hearing or genetic disorders , usually in the form progressive hearing loss .
data in the literature suggest that any undetected impairment , even of a mild degree , can significantly affect the language development and social and emotional development of children , as well as their educational achievements [ 13,13 ] .
for example , undetected mild unilateral hearing loss can cause difficulties in speech understanding and problems with sound - source location , significantly affecting the learning process .
these children do not achieve the same progress in school as their peers with good hearing , and 40% of school - age children with unilateral hearing loss fail final - year exams and must repeat a class .
studies in various populations show that 7695% of all examined children had this disease at least once during early childhood .
there is a growing incidence of high - frequency hearing loss in young children caused by listening to loud music through headphones [ 1618 ] .
other causes of hearing loss in school - age children include infectious diseases ( e.g. , mumps , measles , and meningitis ) , mechanical injuries , and congenital cholesteatoma . in 1999 ,
the institute of physiology and pathology of hearing ( warsaw , poland ) , conducted hearing screening tests in different regions of poland , assessing a group of more than 6200 school - age children .
data from this study suggested that 1 in every 5 children aged 618 years has hearing problems , with the most common locus in the middle ear . in 2008
a team from the institute of physiology and pathology ( warsaw , poland ) carried out numerous mass - screening programs for a period of 4 years . to ensure credible results , unique devices and proprietary solutions were developed . in a period spanning 4 years , more than 300 000 school - age children were assessed .
the important innovation of this program was in choosing primary schools located not in the big cities , but in small schools in urban peripheries . during this period ,
specific computerized tools were developed ( e.g. , the sense examination - platform szok , which is a telemedicine model ) that made possible the organization and performance of hearing tests at relatively low costs .
in addition , medical specialists were able to review , via the platform ,  remotely collected data  and to identify children requiring additional care .
the data from this study showed that 714% of the assessed children had peripheral hearing loss . for 70% of those children it was the first hearing screening test in their life and for 60% of these children
these large - scale screening experiences called for a european scientific consensus agreement , which was defined and signed during the european federation of audiology societies ( efas ) meeting in june 2011 , at warsaw , poland . as a result of the consensus agreement and under the auspices of the institute of physiology and pathology of hearing , a number of pilot hearing screening programs were started in various countries [ 2224 ] , promoting hearing - loss detection and treatment of communication disorders in young school - age children .
the medical community was exposed to information regarding the screening equipment developed in poland and various organizational solutions ( szok ) that allow data collection on a larger scale .
the project was organized in cooperation with the mz - rt national medical center ( dushanbe , tajikistan ) , the trade and investment promotion section of the polish embassy in tashkent , and the department of otolaryngology of abuali ibni sino tajik state medical university in dushanbe .
the objectives of this pilot project were : ( i ) to perform audiometry screening tests in schools and to classify the results via a telemedicine model ; ( ii ) to provide , if possible , medical consultation ; and ( iii ) to raise awareness , among both medical specialists and parents in tajikistan , about the potential causes of hearing loss and the possibilities for prophylaxis , diagnosis , treatment , and rehabilitation .
due to significant differences in the socia - economic levels , these 2 public schools were randomly chosen , excluding elite private schools . in one of the schools
the pilot study assessed a total of 143 ( 286 ears ) students aged 78 years .
testing was conducted by a team from the institute and from the abuali ibni sino tajik state medical university ( medical doctors and other specialists ) .
the final results were given to the directors of the schools , who contacted the parents of the children who did not pass the screening , for further clinical assessments and information on the observed hearing deficits .
the model used remote client devices and software developed during the 2008 polish screening program .
additional details on the model / platform are presented in sections a2 and a3 in the appendix .
tests were conducted in quiet rooms in order to determine hearing threshold in the 5008000 hz range ( see additional details in section a1 of the appendix ) , with the same paradigms as in a previous study . according to already published criteria ,
cases presenting threshold levels > 25 db at 1 or more frequencies or in 1 ear were marked with a hearing loss status .
prior to testing , the children s parents were informed of the testing procedures and provided their written consent .
they had the option to receive additional information by completing a questionnaire with data on the potential causes of the child s hearing problems , medical history , possible presence of tinnitus , and any presence of learning difficulties . in total ,
the results of the individual tests ( pure tone averages and questionnaires ) were sent via an internet connection to the  szok  platform via encrypted lines .
test results presenting a hearing loss status were divided into 2 classes : subjects with unilateral or bilateral hearing losses .
the subjects in each class were further assigned into 3 groups according to the pattern of their corresponding audiograms : low - frequency hearing loss ( lfhl )  the value of the hearing threshold for the frequencies of 500 and/or 1000 hz was at least 25 db hl , while the hearing threshold for the frequencies of 2000 , 4000 , and 8000 hz did not exceed 20 db hl ; high - frequency hearing loss ( hfhl )  the value of the hearing threshold for the frequencies of 4000 and/or 8000 hz was at least 25 db hl , and for the frequencies of 500 , 1000 , and 2000 hz it did not exceed 20 db hl ; other  the hearing threshold exceeded 20 db hl for at least 2 non - adjacent frequencies .
this category was initially called mixed ( i.e. , low- and high - frequency losses ) , but the name improperly suggested the existence of a specific middle and inner ear pathology and it was abandoned for a more generic term . based on the hearing test results and the questionnaire outcomes , and in accordance with the screening criteria developed during the programs implemented in poland , medical specialists from the institute of physiology and pathology of hearing ( ifps ) classified children with hearing losses into 2 groups : ( i ) a group requiring further clinical care ; and ( ii ) a group requiring continuous monitoring over time , according to standard hearing prophylaxis procedures . the parents of the latter group obtained additional information on hearing disorders and the various factors causing the deterioration of hearing .
analyses of variance ( anova ) was conducted with spss version 16.0 at a significance level of p 0.05 .
the testing variables were defined as follows : school id / language ; gender ; screening outcome ( pass / fail ) ; unilateral hearing impairment ; bilateral hearing impairment ; and lateralization ( right / left impaired ear ) . the age variable was not tested because it was found to be homogenous in the assessed sample ( i.e. , the children had the same age ) .
the use of the remote client devices ( pcs ) and the transmission of data via the szok platform did not present any particular technical complications . on occasion , due to
poor internet connections ( transmission rates below 40 kb / s ) , the transmission of data took twice the time necessary , but no corrupted data were reported .
the anova analyses suggested that the language ( i.e. , the site of assessment ) was a significant factor in every tested variable , but this was caused by the asymmetric sample sizes taken from the 2 schools ( see numbers of participants in table 1 ) .
no gender effects were observed on the screening outcome or on the incidence of unilateral / bilateral hearing impairment . in terms of screening
, 109 children passed the set criteria , while 34 children ( 24% ) presented audiometric levels above the 25-db criterion and were considered as refer cases . in both schools , the proportion of bilateral to unilateral hearing impairment was found to be very similar , at close to 1:1 .
based on the screening results of the 34 refer cases and the data gathered from the questionnaires , audiologists and otolaryngologists from the ifps referred 24 students to further specialist care .
the parents of the remaining 10 students were provided with information on hearing loss prophylactic procedures .
the data are summarized in table 1 . in terms of ears presenting hearing losses ,
the total number was 51 , derived from 17 unilateral and 17 bilateral cases . among these
, 31.4% ( 16 ears ) presented low - frequency hearing loss ( lfhl ) , 25.5% ( 13 ears ) high - frequency hearing loss ( hfhl ) , and the remaining 43.1% ( 22 ears ) presented hearing losses involving all tested frequencies .
for the low and high - frequency loss - groups , anova analyses showed a significant lateralization effect favoring the right ear .
similarly , for the cases classified in the  other  category , anova analyses showed a lateralization effect favoring the left ear .
due to the small numbers of ears in these groups , these observations may be slightly biased .
the questionnaires showed that only 9 ( 37% ) of the 24 children needing additional health care had previously undergone hearing tests .
children with refer screening results had experienced otitis media twice as often as the other normal children and had a runny nose during the hearing tests at school .
the objective of this pilot hearing screening program in tajikistan was to validate a telemedicine model with methods and procedures already tested in other programs , in a region where hearing screening is rare .
data were collected from first - graders and the hearing screening outcomes were enriched with additional information from questionnaires . the latter proved to be an adequate tool in assessing non - specific information related to screening , such as otitis incidence , tinnitus incidence , and runny nose incidence .
unfortunately , questionnaires require time and smooth collaboration between parents and the audiology staff and these factors in many instances prevent the proper collection of information .
the data suggest that almost 1 in 4 students ( i.e. , 34/143=23.7% ) has a hearing impairment .
data from previous hearing screening tests conducted by the institute of physiology and pathology of hearing in 1999 ( 5 , 15 ) showed a lower incidence , suggesting that 1 in 5 ( 20% ) students has a hearing problem .
although these studies assessed different sample sizes and children of different ages , the hearing deficit estimates successfully describe the variability that commonly characterizes hearing screening outcomes in school - age children .
thirty - four percent of the tested children in tajikistan were diagnosed with a low - frequency hearing loss .
similar data have been reported in a study in nigeria , where 167 out of 500 examined children ( 33.4% ) presented lfhl in their right ear and 39 in their left ear .
very different data were reported from an american population , where the percentage of children with lfhl was reported as 7.1% .
the differences in the results between prior studies and the tajikistan data may be caused by the fact that the research in tajikistan was carried out in the autumn , when there is an increased incidence of upper respiratory tract infections ( urti ) .
research conducted at the pediatric clinic of otolaryngology , audiology , and phoniatrics of the medical university of lodz , poland showed a correlation between urti and hearing loss .
the data from the tajikistan project showed that the low- and high - frequency hearing loss occurs more likely in the right ear than in the left .
similar results were observed in studies in nigeria , where there is a higher incidence of hearing loss involving high frequencies in the right ear . in these tests ,
high - frequency hearing loss occurred almost 3 times more often in the right ear as in the left .
data from this study suggest that for subjects presenting hearing losses at multiple frequencies , there is a strong lateralization effect towards the left ear .
these findings confirm the data trends found in a previous study by the same authors in a pilot study in poland .
nevertheless , the findings in both studies refer to a finite sample size ; therefore , data from a larger pool of subjects should be considered prior to forming any definite conclusions . according to kuppler , the most common hearing disorder is the unilateral hearing loss , which is found in approximately 3% of school - aged children .
reported values of unilateral hearing loss incidence as high as 88% ( 59/67 ) in a group of 296 assessed children , of which 67 presented hearing deficits .
conducted screening tests in 6166 american children aged 619 years ; almost 15% of the children presented a low- or high - frequency hearing loss with 82% unilateral losses .
data from an iranian children population   report an incidence of unilateral hearing loss of 75% of all reported hearing losses . in the present study the incidence of unilateral hearing disorders was 50% ( 17/34 cases ) , an estimate which is much lower than the estimates reported in the above - mentioned studies .
a number of hypotheses ( or their combinations ) might explain this outcome , such as : ( i ) the population of dushanbe has this particular characteristic ; ( ii ) the assessed sample of 143 students did not accurately represent the characteristics of the general population ; and ( iii ) previous studies considered a wider age interval , which could have led to different unilateral / bilateral hearing deficit ratios .
the findings of the present study suggest that many factors play important roles in the data reported from child screening programs .
the age - range and the sample size of the assessed population are important , but one has to also consider other factors such as the hearing assessment protocols and the instrumentation errors during the data assessment .
the proposed screening procedures allow the detection not only of children with hearing loss , but also those with other hearing disorders , such as tinnitus . according to data in the literature ,
data from the current study show that 9% of the normal hearing group who passed the screening has tinnitus . for the cases classified to a group requiring further clinical care ,
additional data from screening in poland have reported an even larger percentage , showing that nearly 32% of children with normal hearing have tinnitus [ 3234 ] .
the successful use of the szok software platform in a population with a different language is a positive step towards a model of telemedicine / telehealth [ 3537 ] serving rural areas where specialist medical care is not available .
the proposed platform can be used not only for screening children but also for starting edhi programs .
the platform was not evaluated in terms of quality of data or transmission efficiency because these tasks were performed in previous studies . despite intenet
a novel aspect of using this telemedicine model in the future could be the education of professionals and families on issues of hearing deficits and intervention policies .
the results of this pilot study confirm that , even in developed countries , the awareness of hearing disorders is low .
many school - age children have hearing loss , but often the problem stays unnoticed by parents and teachers .
the data from the present study suggest that : it is possible to apply a telemedicine model to assess the hearing status of children and to provide long - distance expert assistance .
the reported data suggest that in dushanbe , tajikistan , 1 in every 4 young children has a hearing deficit .
the incidence of unilateral hearing loss was very similar to the incidence of bilateral losses .
this estimate is much lower than the figures presented in previous reports in the literature .
a number of factors ( e.g. , age , sample size , and protocol used ) , can significantly influence these values ; therefore , direct comparison of screening outcomes from various studies can be difficult .
audiometry testing was conducted during lecture hours in quite rooms ( noise level=4550 db a ) .
the testing audiometers could also measure ambient noise and testing was stopped when the noise level before and during testing exceeded 50 db a. in a free - field audiometry testing , it is very difficult to obtain low frequency ( 125 and 250 hz ) threshold estimates without many repetitions .
the low audiometric frequencies were excluded from the tajikistan testing protocol . since the main deliverable of the project was to identify the pros and cons of future screening guidelines , this procedural compromise was considered acceptable .
the sense examination platform ( szok ) is a telemedicine model for screening and testing : ( i ) hearing and sight ; and ( ii ) speech in children , young adults , and , in general , of those with special needs .
the system was developed by the institute of sensory organs in collaboration with the institute of physiology and pathology of hearing ( warsaw , poland ) .
the sense examination platform is equipped with a variety of screening tests enabling it to detect a number of dysfunctions in the field of hearing , sight , and speech .
in addition , the platform was designed to collect data for surveys and general epidemiological research .
the platform is built around an internet network solution , interfacing a central computer system and a series of portable computers ( remote client devices ) equipped with audiometric headphones and a response - button interface .
the platform allows the user to conduct the following tests : audiometric testing ( module audiogram 2009 ) : this feature allows the user to perform air conduction audiometric testing for each ear separately , in a tone frequency range from 250 to 8000 hz and for hearing threshold levels not exceeding 80 db hl .
hearing screening test ( module i can hear 2009 ) : this feature enables the implementation of hearing screening tests for tones at the frequencies 1000 , 2000 , and 4000 hz ( in various stimulus intensities ) and the assessment of speech intelligibility in noise .
speech screening test ( module i can speak 2009 ) : the speech test is carried out to obtain reliable information on : ( i ) the quality of verbal behavior of the child and ( ii ) the degree of speech development ( or of any potential delays ) and any pathological linguistic phenomena occurring in the speech of the child .
sight screening test ( module i can see 2009 ) : the sight screening test is based on the contrast differentiation test , the color vision test , and the stereoscopic vision test . audiological survey ( module survey 2009 ) : this module allows the user to conduct a general survey regarding the hearing , sight , and speech of a patient .
the surveys were developed by specialists based on years of experience in specific areas and they provide reliable information on the tested person .
test module ddt 2009 : this is a dichotic listening test . during the test ,
pairs of sounds are presented to each ear and the task of the tested subjects is to repeat what they heard in one or both ears .
test module gdt 2009 : this test allows assessment of the potential of perception of gaps in noise . during the test
 backgroundaccording to the guidelines of the european scientific consensus on hearing ( european federation of audiology societies  
 efas congress , june 2011 , warsaw , poland ) , the detection and treatment of communication disorders in early school - age children is of the highest importance . 
 this objective was adopted by the polish president of the efas council from the second half of 2011 ; as a result , pilot programs on children s hearing screening were initiated in various european countries . 
 this paper reports data from a pilot program in dushanbe , tajikistan.material/methodswe randomly selected 143 children from 2 primary schools . 
 each child was assessed by pure tone audiometry and 2 questionnaires ( dedicated to parents and children ) . 
 the study allowed the validation of : ( i ) hearing screening procedures in young children , and ( ii ) data collection via a telemedicine model.resultshearing impairments were identified in 34 cases ( 23.7% ) with a 50% ratio between unilateral and bilateral losses . 
 we found a higher incidence of hearing impairment in children than that reported in previous polish studies.conclusionsthe data from the present study suggest that it is possible to use a telemedicine model to assess the hearing status of children and to provide a long - distance expert assistance . 
 the latter is very important for rural areas without specialized medical services . 
Background
Material and Methods
Results
Discussion
Conclusions
A1: Pure tone audiometry testing in free field
A2. Description of the SZOK Platform
A3. Design and testing protocols