Acoustic Bulletin the place for the latest news on indoor acoustic environment



From March to June this year, huge screening on 7-years old children’s hearing was done in 7 eastern provinces of Poland (with 42,3 % of total country population). During 4 months, 85% of seven years old children on this territory were examined. The results point out that 20% of them have different forms of permanent or temporary hearing impairment. Big scale of this problem indicate that more strict classroom acoustic demands, used to determine environment for hearing impaired persons, should be applied commonly to all types of schools.

Program was conducted by Institute of Hearing Physiology and Pathology in Warsaw (IFiPS) with help of Hearing Impaired and Deaf Persons’ Friends Association and Board of Hearing Pathophysiology, Speech and Communication Disorders of Polish Academy of Sciences.
The main goals of the screening program were:
– detection of different forms of hearing impairment: conductive, sensorineural and central
processing disorders,
– spreading out knowledge about hearing protection, hearing impairment, possible therapy and
– improving accessibility for hearing examination for total population.
Tests were done using mobile multimedia hearing and speech screening system constructed in cooperation with specialist from Multimedia Systems Dept. in Gdańsk University of Technology. Average test of single pupil lasted 9 minutes and consisted of: checking hearing threshold in range of 250-8000 Hz, checking brain ability to process heard sounds and recording of examined individual’s speech. Individual results were immediately send to project coordinator’s server in IFiPS.
Trained volunteers visited 5701 primary schools (88,4% of this type school in the region) and examined 80.592 seven years old children (84,3% of total 7 years old children in area). Additionally, 12.284 older (8-12 years) pupils were also examined.
During whole test program following examinations were done:
– audiograms 92.876
– audiology questionnaires: 68.433
– central hearing test: 44.731
– word tests 31.161
– speech recordings 56.248
Test results showed following prevalence of hearing disorders.
Peripheral hearing disorders (conductive and sensorineural) 13,7%
Central processing disorders 15,1%
Both above malfunctions 19,4%
Hearing loss >30dB in whole range of frequencies 0,7%
Hearing loss >30dB in high frequencies (over 4 kHz) 1,1 %
In the group of 7710 children with the most serious hearing impairment, 60% of parents didn’t spot any problem.
According to data from questionnaires 33% of children have permanent or temporary tinnitius.
In the group of 10.087 children it was possible to compare actual hearing test results with other ones done just after their birth. The hearing impairment prevalence ratio grew from 0,26 % to 14,4%.
Why within first seven years of life prevalence of hearing disorders is growing 55 times? That is mostly an influence of environment. Authors of the program are naming causes:
– native disorders that come out during child growth
– conductive disorders as temporary effect of upper airways infections (in this age it can be 30%
of cases – that factor is decreasing with age)
– a third tonsil
– bony face injuries
– noise (growing factor – due to noisy environment, “noisy culture”, using earphones)
– drugs (mostly antibiotics) side effect (decreasing factor – due to growing conscience)
IFiPS started also another screening program: hearing test of whole population of 12 years old pupils in Warsaw. Similar action will be repeated in 2009 and 2010 to check possible change drift. First result are pointing out that hearing impairment ratio is similar like among 7 years old, but the reasons differs. Number of cases caused by upper airways infections decreased while number of malfunction caused by noise increased.

Acoustics miscellaneous 220

Related Blog Posts