Warning: This post relies heavily on Wikipedia for definitions.
Warning: There is some math involved.
When I was in training, my wife called to talk about something or other and was astounded at the background noise. I was working on a pediatric floor that had an old ward-like layout (one big room with the beds separated by curtains instead of private rooms). She said, “How can you work with that much noise and be so sensitive to noise at home?” Since then I have been fascinated with the culture of noise in medical situations, especially the Emergency Department.
Measuring Sound
That interest was recently rekindled so, I down-loaded an app for my phone that measures decibel readings and gathered some readings. I also obtained some comparison sample readings from da ‘net. But decibel is a fickle wench. It is apparently a logarithmic scale and therefore it cannot be summed up by simple addition (pun intended). Therefore multiple devices do not add like simple math. So, 2 devices producing 50 decibels each do not produce 100 decibels. They are a multiple of 2 and the log of 2 is .301. To obtain the decibel, increase .301 x 10=3.5. Then, 3.5 + 50=53.Straight forward, right? Not to me.1
Table of ED Alarm Sounds
- Home 28 db
- Heart rate monitor 59 db
- Conversation in the work area 45-77 db
- General ED area 45 db
- Moderately loud 60 db
- General ED at shift change 63 db
- Nurse call light 66 db
- Escape alarm 78 db
- Zamboni 78 db
- Loud 90 db
- Very loud 100 db
- Painfully loud 120 db
That’s Alarming
Wikipedia says, “An alarm device or system of alarm devices gives an audible, visual or other form of alarm signal about a problem or condition.”2 But, nowhere on the site does it mention heart monitors with heart rate alarms, blood pressure alarms, pulse-ox alarms, any of the multiple alarms on ventilators or bipap machines. Nowhere is there mention of the escape alarms for those patients that are under police, court or civil custody. There is no consideration for the patient call alarm (really a nurse call alarm, but who wants to fight with tradition). Each alarm has it’s unique tone, rhythm, volume, pitch and cadence. At any one time there might be no alarms sounding, 10 alarms of the same type sounding at once or 10 different types of alarms sounding at once.
When an alarm engages one needs to ask, Is it real or are the alarm parameters set correctly (or not)? When the alarm turns on or off, I have experienced that the parameters are often not entered correctly. For example, say our institution sees 60K patients/yr and 40% are pediatrics, that’s 24,000 pediatric patients/yr and 3/4 of the nurses don’t know what the normal pediatric HR, BP values are for a given age. Of course, not all pediatric patients end up on a monitor, but enough do that it contributes to the cacophony.
The Ground Rules
Sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.3
A musical tone is characterized by its duration, pitch, intensity (or loudness), and timbre (or quality). It may be simple (sinusoidal) or complex (2 or more simple tones).4
Rhythm has a general meaning of regular recurrence or pattern in time.5
There are various definitions of volume/amplitude …, which are all functions of the magnitude of the differences between the variable’s extreme values.6
Harmonic cadence is a progression of (at least) two chords that concludes a phrase, section, or piece of music.7
Pitch …is the quality that makes it possible to judge sounds as “higher” and “lower” in the sense associated with musical melodies.8
Noise is unwanted sound judged to be unpleasant, loud or disruptive to hearing. From a physics standpoint, noise is indistinguishable from sound…9
Noise pollution is a…noise with harmful impact on the activity of human or animal life.10
We have 7 primary variables, each with a huge number of secondary variables within the primary variable. I don’t want to think about calculating the number of combinations that could be had to create a unique alarm sound.
And then, there is the affect that electronically generated sound effects electronically received sound. Hearing aids folks. For some reason these alarms have a masking effect through a hearing aid that causes the reception of human generated sound to be less than optimal. In other words, when the alarms go off, a hearing aid wearer can’t hear another’s voice. As you will read below, there isn’t much time in an ED when an alarm isn’t going off, somewhere or everywhere.
HIPPA
The Health Insurance Portability and Accountability Act of 1996 …”was created primarily to modernize the flow of healthcare information, stipulate how Personally Identifiable Information is maintained by the healthcare and healthcare insurance industries[, how it] should be protected from fraud and theft, and address limitations on healthcare insurance coverage.” Basically, in common use it governs confidentially of all patient care.11
In the Emergency Department we have 39 rooms crammed into a tight space (for 39 rooms) and for some reason, the doors are mostly left open. Even while the nurse, doctor or other staff ask their questions and examine the patient. To the patients and family in the adjacent rooms, it’s like watching a live YouTube reality show. So, even if the noise level may be on the level of normal conversation, the noise pollution may have more impact than the providers are aware of. And then there are the hard of hearing, to whom one has to yell, “When did you last have a bowel movement, Mr Smith?”
The ED is usually a noisy, hectic, fast paced place. This often leaves the staff dependent on communicating verbally, in a loud verbal interchange. Did I mention that most of the nearby patients and family are listening with rapt attention? Sitting at the nurses desk, Nurse #1 loudly asks Nurse #2, “Did you hear about Bobbie Jo at the party last night? Man, was she smashed. I’m surprised she made it to work today.”
Alarm Fatigue
Surely you’ve heard of Aesop’s Fable, The Boy Who Cried Wolf? It is a survival technique of humans, actually all animals of prey, that if a threat happens over and over with no harm occurring, then the event must be safe. Consider the attraction of cats or dogs to humans. I don’t think this is true, but it’s a nice segue into this section. But I had you for a second there, didn’t I?
If you hear the same alarm many times during your 12 hour shift, and most of them are false alarms, you tend to tune them out. For example, almost every husband is accused of selective hearing by the 10th year of marriage, if not sooner. For 37 years it has amazed me that medical staff tend to ignore alarms at work. But, I admit that I cannot remember one single incident that a bad outcome occurred. That must mean that medical staff have an innate ability to sense when things go south. I can think of innumerable times that one or another staff just happened to walk in when something bad occurred, before the alarms went off.
But, sitting there surfing the net on your cell or buying your next couch on Amazon while alarms are blaring just doesn’t seem right.
Non-alarm Machine Noise
An ER is like the rest of the hospital in that it needs to be cleaned and maintained (and are still one of the filthiest places on earth). To sweep and mop by hand is tiresome and expensive. So our hospital has a Zamboni-like floor cleaning machine. It is one of the loudest machines in the department, throwing the sign out front, “Quiet – Hospital Zone”, out the door.12
The staff work area has 21 computer work stations plus a few COWs (meaning a computer on wheels. A term which locally has been banned because a patient might take offense if they took the term out of context. I guess a bovine cow might also, but hey). There is a computer work station in all of the 39 rooms. There are portable fans and space heaters at many of the work stations. The American Hospital Association reports that there are 5,564 hospitals in the US. There are bigger and there are smaller but I consider ours is about average in size. That’s a lot of white noise. Save your money and just listen to your computer if you want generated white noise.
Every one of these devices emit sound. Sometime in the future this sound/noise may be considered sound/noise pollution. There was a case where a man was arrested in New York City for discharging a firearm in the city. He shot his computer. Maybe it was too loud or too obnoxious. The term “going postal” was a term derived from the fairly common occurrence, in the 1970-1980’s, of disgruntled postal workers (USPS) showing up at work with a gun and shooting a few fellow workers or bosses. We all know of the the recent horror of students taking guns to school and shooting fellow students or teachers.
Someday, you might see the term going “medical” come into use. If it does, I think it will be found to be because of the toxic nature of noise pollution in the ED.
From your grumpy Uncle Dave. Deaf to the human voice but keen on the alarms, what with hearing aids and all.
This post was instigated by Amanda Taylor!
- https://www.quora.com/How-do-decibels-add-up-If-you-have-two-pieces-of-equipment-creating-50-decibels-of-sound-in-a-small-space-is-the-the-total-noise-level-100-decibels
- https://en.wikipedia.org/wiki/Alarm_device
- https://en.wikipedia.org/wiki/Sound.
- https://en.wikipedia.org/wiki/Musical_tone
- https://en.wikipedia.org/wiki/Rhythm
- https://en.wikipedia.org/wiki/Volume
- https://en.wikipedia.org/wiki/Cadence
- https://en.wikipedia.org/wiki/Pitch_(music)
- https://en.wikipedia.org/wiki/Noise
- https://en.wikipedia.org/wiki/Noise_pollution
- https://en.wikipedia.org/wiki/Health_Insurance_Portability_and_Accountability_Act
- https://farm4.staticflickr.com/3414/3423689241_e8c28c2c5b_z.jpg
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