Showing 5 results for Noise
Nemati Sh, Amiridavan M, Jamshidi M, Saberi A, Majlesi A,
Volume 65, Issue 4 (7-2007)
Abstract
Background: Sudden sensorinueural hearing loss (SSNHL) is a baffling condition for patients, and its etiology, audiologic characteristics, prognostic factors, and treatment are still controversial.
Methods: In this prospective study, we performed pure tone audiometry (PTA), impedance acoustics (IA), auditory brainstem responses (ABR), otoacoustic emissions (OAE), and transiently evoked otoacoustic emissions (TEOAE) before beginning treatment for 53 patients with SSNHL. We then entered each patient, randomly and alternately, in one of two treatment groups: oral steroids + acyclovir vs. intravenous urographin.
Results: In 22 (41.5%) of the 53 patients (22 female, 31 male), we found negative or no signal to noise ratio and overall correlation in TEOAE. Furthermore, 26 cases (49%) had positive overall correlations less than 50%, and five cases (4.4%) had overall correlations >50%. Although 15 cases (28.3%) responded well, 20 cases (37.7%) showed only a partial response, and 18 cases (33.9%) had poor or no response to our treatment. The mean value for overall correlation in the three subgroups of patients (no response, partial response, and complete response) was -3.5% (±1/16%), + 11% (±1.99%), and +36.6% (±3.07%) respectively (P = 0.01). From 52 cases, 20 had no reproducible wave in ABR (38.5%), three cases had abnormal ABR with normal OAE, all of which responded completely to treatments. Thirteen cases had abnormal ABR and OAE, none of which responded to treatment, and six cases had normal ABR with abnormal OAE, which often responded to treatment.
Conclusions: ABR and OAE may be useful in the diagnosis of SSNHL and determining the site of such lesions as ischemia or neuropathy. The overall correlation (and S/N ratio) in TEOAE is a valuable prognostic factor in SSNHL.
Talaei T, Monsefi M, Vojdani Z, Dehghani F, Arab M R,
Volume 65, Issue 6 (9-2007)
Abstract
Background: Some pregnant women are exposed to occupational noise, a risk factor for the development of the auditory system. The auditory system is one of the areas in embryonic development in which noise might induce aberrant development. Noise can change the gene expression pattern of an embryo and thereby modify the physiology of the auditory system. Therefore, noise can change the molecular structure of the developing ear. One of the critical molecules involved in development of auditory system is glycoconjugate. The aim of this study was to investigate the molecular changes of the developing spiral ganglion after exposure to industrial levels of noise.
Methods: A total of 42 pregnant mice were divided into control and experimental groups. Each group was further divided into three subgroups. The three experimental subgroups were exposed to daily noise with an intensity of 100 db for 2.5 hours until sacrifice (for the first group to be sacrificed) or day seven of postnatal life (for the other two groups). The mice offspring were sacrificed at the first, seventh and 14th days of postnatal life. The inner ears were prepared histologically. The specimens were stained with the lectins wheat germ antigen (WGA), peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA) and BSAI-B4.
Results: The results indicated that, although there were no histological changes at the light-microscopic level in the ear development, statistical analysis showed that there was a significant decrease in the uptake of the BSA1-B4 lectin by neurons of spiral ganglion in 14th day of postnatal life in the experimental group compared to that of the control group (p<0.05).
Conclusions: After noise exposure, in spite of normal neuronal structure, these cells were modified at the molecular level, especially in glycoconjugate expression, influencing the normal physiology of neurons and causing auditory disorders.
Barzegar M, Talaei Zavareh Sa, Salami M,
Volume 68, Issue 10 (1-2011)
Abstract
Background: Numerous evidences indicate that various environmental stresses during
pregnancy affect physiological behavior of the offspring. This experimental
study was designed to investigate the effect of noise stress during prenatal
period of rats on spatial learning and memory and plasma corticostrone level in
postnatal life.
Methods: Three groups of pregnant rats were given daily noise stress with durations of
two and/ or four hours in last week of pregnancy period. The fourth group was
left unstressed. The male offspring from the unstressed and different stressed
groups were assigned as controls and stressed groups. The animals were
introduced to a spatial task in Morris water maze 4
trials/day for five consecutive days. The probe test was performed on the 5th day of the experiment. The delay in findings and the distance passed to locate
the target platform were assessed as the spatial learning.
Results: Our results showed that prenatal exposure to noise stress for two and/ or four
hours a day, leads to impaired acquisition of spatial learning in the postnatal
animals. The plasma level of corticostrone in the two stressed groups of rats
markedly matched with their behavioral function. Prenatal exposure to 1-
hour noise stress revealed no effects on the offsprings' behavior and plasma
corticostrone level.
Conclusion: Based on our study results, it seems that applied range of stress which is
executed through the noise stress could increase the plasma corticostrone level
and could decrease spatial learning and memory of adult male offspring.
Ahmad Joneidi Jafari , Ebrahim Sahebdel , Asghar Hajipour , Mihan Jafari Javid , Seyed Mohammad Mireskandari , Kasra Karvandian , Afshin Jafarzadeh , Shahram Samadi ,
Volume 71, Issue 11 (2-2014)
Abstract
Background: Surgeons and anesthesiologists working in orthopedic operating theatres are exposed to significant noise pollution due to the use of powered instruments. This may carry a risk of noise-induced hearing loss. The present study was designed to quantify the noise pollution experienced by anesthesiologists at Imam Khomeini Hospital which is one of the largest Iranian hospitals.
Methods: Prior to beginning of any operation a sound level meter was worn by the anesthesiologist at the level of chest pocket. Basal sound level was recorded. All changes in the sound level of 25 operation rooms and two related pass ways were recorded and the mean sound level along with maximum sound level were noted. These data were analyzed by SPSS version 17. For comparing the mean values, the One way ANOVA and Post-Hoc analysis was used. Noise exposures were compared with occupational health guidelines.
Results: Our comparative data showed that orthopedic operation room had the highest level of noise, indicating that orthopedic operation room is significantly suffered by the most types of noise with the P value of 0.002. This is contrast to the sound levels at the other operation rooms which were at same range and were not significantly different. Comparison of the maximum sound level between these 27 places showed that orthopedic and one of general surgery room had top two maximum sound levels.
Conclusion: Overall total noise dose during all types of surgeries was measured as twice of permitted dose and also orthopedic and general operation rooms experience brief periods of noise exposure in excess.
Nammam Ali Azadi , Shahram Sadeghi , Mohammad Hossien Saghi ,
Volume 73, Issue 5 (8-2015)
Abstract
Background: One of the critical unit in each hospital is intensive care unit (ICU). The United States’ Environmental Protection Agency (EPA) recommends to control the noise level of this unit in order to not exceed 45 decibels (dBA) during the day and 35 dBA at night. In this study, our goal was to evaluate the noise level at adult and neonatal ICUs at some Sanandaj’s hospitals, Iran.
Methods: This cross-sectional study was conducted from May 4th to June 4th 2012 in adult and neonatal intensive care units at three major hospitals in Sanandaj (Besat, Tohid and Tamin-Ejtemaei). In order to assess the noise level properly, measurements obtained during the days and nights. At a given day, a unit was selected randomly and measurement of sound levels obtained successively within two-hour periods. The noise levels were measured in decibels using a sound level meter (SLM). This process took four weeks to be completed (one week per unit). In the end of study, the total of 336 records of noise levels were obtained. Descriptive analysis as well as fitting a mixed effect models were used to interpret collected observations. All statistical analysis performed using R developed by R core team.
Results: The preliminary analysis of observations showed that mean level of noise varied from 65 to 71 dBA among ICUs under study. Noise levels during the day were slightly higher than that of were observed during the night. Descriptive analysis of observations showed no major differences between the noise levels over the time and between the days/nights. Fitting a mixed-effects model showed significant differences of the noise levels between ICUs (P< 0.001).
Conclusion: We found the noise levels were always above the EPA thresholds at all three hospitals both during the day and night. It is recommended to train hospital officials and staffs for keeping noise levels to an acceptable level.
