@2024 Afarand., IRAN

---

ISSN: 2008-2630    Iranian Journal of War & Public Health 2015;7(1):29-34

Background
… [1] Hearing impairments regardless of the age, affect the quality of life [2]. … [3-9]. Hearing impairments due to land mine explosion and the ways of treatment have been considered since 1980 [10]. In the military environments, excessive exposure to sound is an effective factor on the hearing system and leads to hearing loss, tinnitus, and Hypersensitivity to the Sound (HSS) [11]. In addition, such exposure can lead to social and behavioral abnormalities via tinnitus and HSS and without hearing loss [11]. The frequency of different types of hearing loss of Iranian children and adolescents from west provinces of Iran, injured by land mines were studied in the present research.
Previous Studies
In the last 30 years, only few studies have been done about the effects of land mines explosion on hearing [5]. In the mines, hearing loss due to explosion sound is very common among the mineworkers [6]. The frequency of the industrial workers with reduced hearing threshold level is very higher than the normal population [7, 8]. One of the most common impairments due to war is hearing impairment with a recorded up to 50% of the impairments [9]. … [12]
Aim(s)
The aim of this study was to collect data and investigate hearing health of Iranian land mine victims less than 18 years old.
Research type
This is a descriptive study.
Research society, place and time
Land mine victims less than 18 years old (78 persons) were studied in February 2010 in Health Camp, Tehran, Iran.
Sampling method and number
23 persons were selected using purposive sampling method.
Used devices&materials
Tinnitus was investigated using Tinnitus Handicap Inventory. Reliability of the questionnaire has been confirmed in the Iranian population using Cronbach’s Alpha 0.96 [13]. Dizziness was investigated using Dizziness Handicap Inventory. Reliability of the questionnaire has been confirmed in the Iranian population using Cronbach’s Alpha 0.89 [14]. Most Comfortable Listening Level test of children was used for sound orientation (localization and lateralization) in a calm and silent environment. Sound orientation was done using TDH-39 (Sonic; Australia) via Low Pass Noise and High Pass Noise with 2KHz cutoff frequency. The results of the orientation test were recorded as 6-point Likert’s Scale (very weak=1, weak=2, moderate=3, good=4, very good=5, and excellent=6). Examination of the ear and investigating any hearing impairment and other information of persons with hearing problems were done by an ear, nose, and throat specialist. Demographic information (age, age at the time of incidence, injury length, and sex) was recorded. Other injuries, besides hearing problems were recoded. Hearing evaluation forms were completed by a specialist physician during 20-30min examination. Audiometric information including Pure Tone Audiometry or PTA (with AC40 instrument; Deltason; Hong Kong), Tympanometry or Impedance (with AZ26; Interacoustics; Denmark), hearing loss type and length, ear tinnitus, dizziness, sound orientation, and drawing audiograms was recorded. Situations leading to hearing impairments, need for hearing aid and other assistive hearing devices, pharmacologic treatment, surgery, and consultation were investigated. Speech perception threshold test was used to determine auditory threshold and to compare the auditory resolution power of the both ears. Data was analyzed using SPSS 19 software. The correlation between hearing loss level and injury length was investigated by Chi-Square Test.
Findings by Text
The mean age of 21 boys (91.3%) and 2 girls (8.7%) with hearing impairments was 16.13±2.05years at the study time (aged between 10 and 18years). Their mean age at the incidence time was 9.47±2.99years (aged between 3 and 15years). 18 persons (78.3%) had other injuries besides hearing loss. 1 person (4.3%) had hearing aids. 2 persons (8.6%) had assistant devices including waterproof cast for the left ear and cast reducing background noise for both ears.13 persons (56.5%) referred to physicians. 6 persons (26.1%) were under pharmacologic treatment. 3 persons (50%) have used Antibiotics for ear infections and 3 other persons (50%) have used Betahistine for dizziness. 5 persons (21.7%) had tympanostomy mastoidectomy surgery which in one of them was bilateral. 1 person (4.3%) had used psychiatric consultation services. Crowded environment (60.8%), telephone call (52.1%), watching TV with the high sound (43.5%), hearing rapid conversation (30.4%), calm and silent environment (21.7%) were the most problematic situations for the victims. The most common hearing loss was sensorineural (Table 1). Tinnitus was observed in 20 persons (87.0%) including right ear in 7 persons, left ear in 4 persons, and both ears in 9 persons. Tinnitus qualities in 13 persons (65%), 6 persons (30%), and 1 person (5%) were high, low, and without diagnosis, respectively. 16 persons (69.5%) had peripheral hearing problems (dizziness in 3 persons, headache in 8 persons, both dizziness and head ache in 5 persons). 10 persons (43.4%), 8 persons (34.8%), 4 persons (17.4%), and 1 person (4.3%) had moderate, very good, good, and weak sound orientation, respectively. The mean injury length was 6.65±2.49years (3 to 13years). Mean hearing loss length was 6.7±2.5years (1 to 13years). There was no significant correlation between injury length and the rate of hearing loss. In speech perception threshold test, the studied persons repeated less than a quarter of the heard words, which was less than a half of the standard value of the test. Mean values of the test for right and left ears were 22.5±16.4 and 20.8±14.5, respectively. The mean resolution power of the left ear was 96.2±5.3, which was in the completely normal domain. Mean resolution power of the right ear was 94.6±6.9, which was very close to the normal domain.
Main comparison to the similar studies
… [15-17] More than three quarters of the victims had tinnitus. More than two-thirds of the victims had peripheral impairments such as headache and dizziness. Half of the victims had moderate sound orientation and lower. About one third of the victims had hearing impairments. The results confirm other studies. In India, loud and dissonant sound of toy guns and firecrackers has led to 2.5% of hearing loss in 9 to 15 years old children and adolescents [18]. Very loud sound from explosion led to about 30% of hearing impairments in victims even after 6.5years from event which confirms the results of other studies. … [19-22]. Unlike other studies in which the prevalence of transmission hearing loss is higher than sensorineural hearing loss, in this study, the frequency of transmission hearing loss type was half of the sensorineural hearing loss frequency. [23, 24]. … [25]
Suggestions
More studies, using different treatment methods and evaluating the effects of each one, ought to be done to obtain more precise results. Satisfaction from the administrated methods should be evaluated.
Limitations
Due to special studied population, there was no possibility to form a proper comparison with the results of other similar studies.
Conclusions
Sudden exposure to the sounds like landmine explosion might lead to hearing impairments such as hearing loss, headache, dizziness, and tinnitus, which might highly affect persons’ quality of life.
Acknowledgments
The researchers feel grateful to Martyrs and Veterans Foundation, Janbazan Medical and Engineering Research Center, and the International Committee of the Red Cross.
Conflict of interest
Non-declared
Ethical Permissions
All procedures were approved by the Ethics Committee of Janbazan Medical and Engineering Research Center.
Funding Sources
The study was funded by Special Veterans Group Center.

TABLES and CHARTS

Show attach file