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Year : 2008  |  Volume : 10  |  Issue : 38  |  Page : 11--13

Noise levels in a tertiary care hospital

A Vinodhkumaradithyaa1, M Srinivasan1, I Ananthalakshmi1, David Pradeep Kumar1, RV Jeba Rajasekhar2, Tennyson Daniel2, P Thirumalaikolundusubramanian3,  
1 Department of Medicine, Madurai Medical College, Madurai-20, India
2 Department of Environment, School of Energy Sciences, Madurai Kamaraj University, Madurai, India
3 Institute of Internal Medicine, Madras Medical College, Chennai-03, Tamilnadu, India

Correspondence Address:
A Vinodhkumaradithyaa
30/130 Lake View Garden I Street, K K Nagar, Madurai - 625 020, Tamilnadu


High levels of noise in hospitals may interfere with patient care services, the doctor-patient relationship and medical education activities. The aim of this study was to assess the noise level at different places in a tertiary care hospital and suggest measures to reduce the noise. Sound levels of fourteen places inside the hospital were recorded using a Digital Sound Level Meter . A total of 20 readings were taken at three minute intervals between successive recordings during the morning (9 to 10 a.m.) and evening hours (6 to 7 p.m.) and analyzed using simple descriptive statistics. The mean equivalent sound pressure levels (Leq) during the morning and evening hours were 70.38 and 64.46 dB(A) respectively. During the morning hours, the maximum Leq was observed in the mortuary (76.70 dBA) whereas the minimum Leq was in the intensive care unit (I.C.U) (58.34 dBA). The maximum and minimum Leq during evening hours were recorded at O.G (Obstetrics and Gynecology) ward (71.86 dBA) and mortuary (57.08 dBA) respectively. The morning hours showed higher levels of noise in most of the places probably due to overcrowding and higher vehicular movement. This study highlights the need for noise monitoring and control measures inside hospital areas.

How to cite this article:
Vinodhkumaradithyaa A, Srinivasan M, Ananthalakshmi I, Kumar DP, Jeba Rajasekhar R V, Daniel T, Thirumalaikolundusubramanian P. Noise levels in a tertiary care hospital.Noise Health 2008;10:11-13

How to cite this URL:
Vinodhkumaradithyaa A, Srinivasan M, Ananthalakshmi I, Kumar DP, Jeba Rajasekhar R V, Daniel T, Thirumalaikolundusubramanian P. Noise levels in a tertiary care hospital. Noise Health [serial online] 2008 [cited 2022 Nov 30 ];10:11-13
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Noise being a major component of dynamic space, is one of the most invasive aspects of the hospital environment. Patients and their families are exposed to sounds overheard through walls and curtains. When patients' acuity is high, their adaptive capacity is low, which results in a greater sensitivity to environmental stressors. Conversations among patients, staff and visitors, sounds of doors, carts, phones, beepers, etc, make up the "sound environment" which is a risk to healthcare. Whether by accident or incident, the accumulation of noise and unwanted distraction adds up to a negative healthcare experience. [1] The International Noise Council [2] and the World Health Organization (WHO) [3] has recommended that noise levels in hospital areas should be 35-40 dB(A) in the daytime and 30-40 dB(A) in the evening.

The present study was undertaken to assess noise levels in different places in the hospital both in the morning and evening hours and to suggest measures to reduce the noise.

 Materials and Methods

This study was conducted after obtaining institutional ethical clearance at a 2200 bedded tertiary care hospital with a bed occupancy rate of 95% and a daily attendance of about 9000 outpatients. The hospital is located on the main road in the heart of the city, adjacent to the northern bank of the river Vaigai. Sound levels in fourteen places inside the hospital were recorded using a Digital Sound Level Meter. The readings are in Decibel, A-weighted (dBA) units representing the sound level measured with the A-weighting network on the sound level meter. This instrument incorporates a type-1 microphone and records sound ranging from 30 to 130 dBA with a sensitivity index of 0.5 dBA. Fast impulse mode was used to record the readings. The sound meter was placed at body level for measurements. A total of 20 readings were taken in the morning and evening hours at three minute intervals between successive recordings. Observations were done during the morning hours between 0900 to 1000 hours and in the evening hours between 1800 and 1900 hours.

The parameter universally used in the discussion of noise pollution is Leq, the equivalent continuous noise level expressed in dB(A), which is the average rate at which energy is received by the human ear during the period monitored. L 10 and L 90 indicate the level exceeding for 10% and 90% of the time respectively, in a record of noise level in a given interval. The other variables obtained were L max and L min which are the maximum and minimum noise levels recorded at each place respectively.

The data were tabulated using Microsoft Excel 2007 and analyzed using simple descriptive statistics.


The mean equivalent sound pressure levels (Leq) were 70.38 dBA in the morning and 64.46 dBA in the evening.

[Table 1] shows Leq, L max , L min , L 10 , L 90 for individual areas during the morning and evening hours.

During the morning hours, the maximum Leq was observed in the mortuary (76.70 dBA) and the minimum Leq was in the I.C.U (58.34 dBA). The maximum and minimum Leq during evenings was recorded at O.G ward (71.86 dBA) and the mortuary (57.08 dBA) respectively.


Noise in a public hospital is unavoidable but at the same time, long-term noise exposure is regarded as a health hazard [4] as it has deleterious physical and psychological effects. [5] Hospital patients require a congenial environt free from toxic levels of noise. [6]

The noise levels in hospitals show an increasing trend of about 0.38 dB per year during daytime hours and 0.42 dB during the nights. [7] The average equivalent noise levels (Leq) found in this study were similar to sound levels found in other healthcare settings. [8],[9],[10],[11],[12],[13] The ambient sound level found in a state psychiatric hospital was 75.7 dB(A). [8] Noise levels in a postanesthesia care unit and in pediatric intensive care units were about 67.1 [9] and 60 dB(A) [10],[11],[12] respectively. The noise level in the wards of a hospital in Taiwan was between 50.3 and 68.1 dBA. [7] The highest peak levels routinely seen during surgery in operating rooms were well in excess of 120 dB. [13] The findings of the present study were consistent with the high noise levels [63-89 dB(A)] recorded in the wards of a teaching hospital in an earlier study. [14]

In India, noise levels in an operation theater were between 65-80 dB(A) during surgery. [15] The average indoor noise levels of three hospitals were found to exceed the permissible limits. [16] Many places even in silence zones had noise levels above 50 dB(A). [17]

In the present study, the average equivalent noise levels (Leq) observed in all places in the hospital highly exceeded the recommended WHO guidelines and a review of objective data indicates similar situations in hospitals throughout the world. [18]

It was alarming to note that ten out of fourteen areas had levels exceeding 70 dBA during the morning hours. The heavy inflow of about 9000 patients every day during the morning hours could probably be one of the contributing factors for such high levels. The highest level of noise [76.70 dB(A)] was noted in the mortuary area in the morning. The emotional outbursts of the relatives of the deceased and vehicular movement of students and doctors in that area might have contributed to the observed noise level. As the mortuary is located near the pediatric department, this high noise level might contribute to undesirable physiological and behavioral effects on the sick children admitted there. [19] The lowest level of noise was observed in the I.C.U (58.34 dBA), which could be because of restricted admission to visitors. It is surprising to note that even the lowest recorded noise level was 18 dBA more than the recommended WHO level of 40 dBA for morning hours. Such high levels could slow down the recovery of patients. [20]

The highest level of noise during the evening hours was recorded in the O.G ward [71.86 dB(A)]. A previous study done by one of the authors on noise due to the traffic on the adjacent main road reports noise levels of 70 dBA. [21] This could be one of the reasons for high levels of noise in that ward. The lowest level was observed in the mortuary area [57.08 dB(A)] in the evenings as the place is mostly deserted then and is located at the far end of the hospital away from the road.

Factors possibly contributing to the high noise levels were high turnover of patients, overcrowding of wards, communication among healthcare providers, incessant conversations by visitors, crying of babies, screaming of children and emotional outbursts, vehicles (engine noise, horns, bells and public vehicles on adjacent roads), location (adjacent to the main road, decreased breathing space between two buildings and lack of silence zones), environmental factors (low number of trees within the hospital premises) and equipments and appliances [22] (mobile phones, alarms of instruments, power generators present near the wards and noise from old fans).

Simple measures like arranging patients in individual rooms, moving equipment and alarms away from patients, [23] relocating nurse stations away from wards, switching mobile phones to vibrating mode, training doctors and nurses to speak more softly [24],[25] can be adopted to reduce noise. Proper site location, city planning, traffic engineering, building construction, [26] equipment selection and maintenance and system management [27],[28] are also necessary for the reduction of hospital noise.

The strength of the study was the identification of diurnal variation. The limitations of the study were of the neglect of seasonal variation and the inability to continuously record noise in different locations due to technical constraints.

Noise levels were found to be high especially in the mornings in most of the areas within the hospital which will interfere with the doctor-patient relationship, [29] patient care services and medical education activities. Hence, there is a need for regular monitoring and measures to control noise levels at different places in the hospital.


We thank the Indian Council of Medical Research for granting Short Term Research Studentship for the first author (ICMR, New Delhi, 21/289/2005-BMS).


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