The constant sounds of machines, alarms, voices, beepers and telephones are nothing out of the ordinary to people who work in hospitals. Like people in almost any working environment, medical staff members adapt to the constant clamor; over time, the ambient noise becomes a normal part of their work life.
However, these sounds are not normal to patients. In fact, they’re far from normal, and studies show that noise in U.S. hospitals adversely affects patient care directly and indirectly. Noise is not only causing additional stress on the infirm, it is causing serious mistakes to be made by medical staff.
Depending on age, the sharpness of their hearing, medication levels, even their culture and fears, the same sounds that hospital staff take for granted are increasing the stress levels and sleep disturbances in patients. Noise in hospitals has been found to cause confusion among patients, contribute to patient falls, and increased administration of medication and restraint use. Prolonged exposure to the ambient noise that is common to hospitals can increase a patient's anxiety and ultimately affect the patient’s well-being and safety.
Noise actually decreases patient confidence in the clinical competence of the staff, according to studies on the effects of noise in hospitals.
Compounding the problem, noise-induced stress impacts other patients and visiting family members exponentially.
Sudden noises like a slammed door or dropped tray may trigger the "startle reflex" in patients, resulting in physical responses such as increased heart and respiratory rate, facial grimacing, elevated blood pressure, muscular flexion and vaso-constriction. Patients exposed to noise continuously can experience increased agitation, altered memory, lowered pain tolerance and feelings of isolation. Such environmentally-triggered symptoms are often medicated or otherwise treated in ways unrelated to their cause.
Even more alarming, distracting sounds have been shown to contribute to medical and nursing errors. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) has pinpointed noise as a potential risk factor related to medical and nursing errors, and recommends ambient sound environments never exceed a level that could prohibit clinicians from clearly understanding each other. In one specific surgical incident, music being played in the operating room was so loud, the surgeon's directions to the anesthesiologist regarding levels of heparin – a drug used to prevent clots - were misunderstood by 8,000 units. This type of incident takes noise past a mere annoyance level and makes it a significant potential safety risk.
EPA recommended guidelines for continuous background noise in hospitals place acceptable daytime levels at 35 decibels, and 40 decibels at night in patient rooms – the equivalent of a very quiet or whispered conversation. But studies show that noise levels in most hospitals are much higher. Noise sources are numerous and loud, and hard surfaces — floors, walls, and ceilings — reflect sound rather than absorb it, causing reverberant sound problems like echo to overlap, linger, and repeat frequently.
While many hospitals are committed to creating a healing environment, the auditory environment, laced with noxious noise, is usually ignored. A healing environment requires both a physical setting conducive to recovery, and an organizational culture that supports patients and families already struggling with stress. The sound environment must be managed in such detail that neither patients nor staff are at risk.
When we talk about managing noise, it is understood that hospitals and other medical facilities cannot be expected to operate in silence.
The EPA defines noise as "any sound that may produce an undesired physiological or psychological effect in an individual or group." This definition accompanies the decibel scale. Therefore, it is necessary to determine whether noise in a particular hospital is an issue, and if so, to what degree.
To minimize the potential for noise to impact patients negatively, standards must be set to establish appropriate sound levels, including recommendations for modifying, maintaining, and purchasing equipment. In addition, repair and maintenance policies should be reviewed to incorporate language to address a quieter environment. An auditory impact query should be part of every new construction project as well as every remodel, equipment addition, and staff event.
A recent study by Blomkvist et al. (in press, 2004) examined the effects of poor versus good sound levels and acoustics on coronary intensive-care patients in a large university hospital in Stockholm, Sweden, by periodically changing the ceiling tiles from sound-reflecting to sound-absorbing tiles. When the sound-absorbing ceiling tiles were in place, patients slept better, registered lower sympathetic arousal (which indicates lower stress levels), and reported that nurses gave them better care.
The Karmanos Cancer Institute in Detroit, Michigan, experienced a 30 percent reduction in medical errors in one unit after it installed acoustical panels and went to decentralized nurse stations. Methodist Hospital in Indianapolis, Indiana, attributed its improved medication error index on noise abatement measures in its coronary critical care unit.
Noisy hospitals can compromise patient care and recovery. Hospitals must take measures to address sound quality and make noise abatement a priority in health care policy.