Noise is a key factor in concussions and affects recovery. I’m convinced of it. The more I research it, the more sure I am that it’s a major factor to look at in-depth. In this post, I’m pulling together information from many sources that show how noise creates symptoms that are attributed to concussion. Check any list of concussion symptoms and then review information about noise effects on health. You’ll find that noise can cause the issues commonly attributed to concussion. Noise causes problems with concentration, sleep, fatigue, headaches, psychological issues such as anxiety, and increased heart rate.

Noise has also been studied for decades. It’s recognized as a serious public health issue. On a worldwide basis. There is much data available, and I think it’s time to look at it from the perspective of concussion recovery and management.

I’ve gathered quite a bit of information here for you to review. This is a very long post. However, I wanted to get all this in one place. My thought is that you could read it and then go back and review all the content available through the links. I can’t imagine you could review it all in one sitting, as it took me a few weeks to review and collect everything. When you look at all this, you will have to take a leap and apply it to concussion. Connect the dots.  Information on noise and concussion specifically isn’t available much, as it hasn’t been looked at yet in detail as far as I can tell.

Update: July 2, 2014 Verified links and updated content as necessary. Update references are included in the text.

Update: July 17, 2018 Updated some content, tested and updated links, and replaced graphics

 

Noise Impacts: General Information

If you’d like a general overview about how noise affects health, I’ve gathered a few articles and studies you can review. The first one in particular covers quite a bit in a short article. Details follow below in subsequent sections.

Noise Pollution: A Modern Plague

Information About Hearing, Communication, and Understanding
Excellent information about hearing and sound all in one spot
From the National Institute of Health (NIH) Curriculum Supplement Series, Grades 7-8: How Your Brain Understands What Your Ear Hears

…

I included this information in my Concussions Post-Injury: Noise as Cause of Symptoms   and am repeating it here because I think it explains much.

“The pain threshold is the high level (high dB) audible sound where the level of pressure of the sound creates discomfort or pain.” (page 6)

“Exposure to moderate levels of noise can cause psychological stress. Other effects can be:

• Annoyance (fear, anger, feeling bothered, feeling involuntarily and unavoidably harmed, and feelings of having privacy invaded), interference with activity
• Headache, tiredness, and irritability are also common reactions to noise
• Possible impairment of intellectual function and completion of complex tasks. Depends on the nature of sound and individual tolerance.”   (page 28)

“Chronic noise exposure impairs cognitive function.” (page 29)

Source: WHO  Children and Noise

Fatigue

What doesn’t cause fatigue for concussion? The question isn’t what causes fatigue, but how each symptom does. That’s my thought. Noise causes fatigue, too. If it’s making it more difficult to concentrate (which it does) then you’re going to tire more quickly. Check anywhere now and you’ll find that it’s recommended that people refrain from or reduce cognitive tasks, especially in the early days following concussion.  For instance, shortening a school day.  If you have to think harder, to concentrate harder to first focus on blocking the noise and then focusing on the actual work, I would imagine that it would cause fatigue much sooner. That’s just an educated guess on my part.

With that in mind, I invite you to take a look at the Julian Treasure TED talk mentioned below. He states that just sitting in the front row of a noisy classroom lessens the need for extra concentration. Maybe you can do something as simple as moving up a few rows in class. Maybe something like that would help.

Concentration

In the course of the past several years, two physicians I respect shared this same information with me. Their thoughts: short-term memory issues are impacted and perhaps caused in part by concentration issues. Since hearing that, I’ve made a concerted effort to concentrate and focus more than I have in the past.

Now let’s look at noise. If noise interferes with concentration, it likely then also affects the symptom of short-term memory, wouldn’t you think? Might that be a reason why you can’t recall what you just read five minutes ago? Or perhaps can’t analyze and think as clearly? Is it harder to concentrate in a noisy classroom? Is there noise in your environment at home, work, or school that’s affecting your ability to concentrate? Do you have a lower threshold of working within a specific decibel level?

I can tell you that since I worked on researching my Noise as Symptoms post, making my noise maps and testing use of earplugs, I’ve made some changes. I’ve started putting in earplugs when I write. Not always, but I’m definitely using them more. I love it. They block out all background noise and it enables me to really focus on my writing.

Noise in the Classroom and Effect on Concentration

Here’s an important short video I suggest you watch in its entirety. It’s another Julian Treasure TED talk. There’s a very interesting section on the effect of noise in the classroom. At the 3:45 mark, he states the following:

“A study in Florida just a few years ago found that if you’re sitting where this photograph was taken in the classroom (row 4) speech intelligibility is just 50%. Children are losing one word in two. Now that doesn’t mean they only get half their education, but it does mean they have to work very hard to join the dots and understand what’s going on.”

Julian Treasure
Why Architects Need to Use Their Ears
TED.com, June 2012

Think about that for a moment. If you have a concussion, doesn’t your brain have to work extra hard to be able to process information – perhaps even more so than indicated in this comment? Wouldn’t you tire more easily or hit the wall sooner? What if a concussee always sat in the first row in a classroom? Would that help?

Sleep

Wow. Noise definitely affects sleep. And sleep, or lack thereof, is, I know, a problem for many. Rather than saying much more, I’ll just suggest that you review the information I’ve gathered here. Look at the excerpts and then go to the source articles and information. The effect of noise on sleep is well-documented.  After reading numerous studies and articles, my thought is this:  fix decibel level exposure first. Employ some noise abatement techniques and adjustments at home (see below). Then combine this with other aspects such as reducing caffeine intake after a certain time period (or similar types of activities) and what doctors suggest. See if that helps in any way. Look at fixing the root problem. With that in mind, read on…

Update July 17, 2018: Removed references to WHO community noise information relating to sleep, which is no longer available on the WHO website.

Noise in Hospitals and Effect on Recovery

There have been many studies regarding noise reduction in hospitals. Noise is recognized to hinder recovery and has resulted in hospital design changes to accommodate noise abatement.

Decibel Levels and Effect on Sleep

Here’s one study that tracked decibel levels and the effect on sleep. One aspect that’s important, I believe, is that is shows how intermittent sounds (such as IV alarms) woke people up. Keep that in mind, as I’ll mention it a little further down in this section. For now, here’s information about that study.

“Evidence-based design meets evidence-based medicine: The sound sleep study is the first study to identify decibel (dB) levels at which 14 typical hospital sounds are too loud for undisturbed sleep. The study’s results and recommendations are expected to drive innovation in design, construction, materials, equipment and care protocols to improve acoustics in healthcare environments, positively impacting medical outcomes and increasing safety.

The sound-sleep study was conducted by two Harvard researchers in Massachusetts General Hospital’s sleep laboratory. While participants slept, researchers played recordings of 14 different noises typically heard in a medical-surgical unit. Arousal information confirmed that at levels commonly experienced by patients, the selected hospital sounds significantly disrupted sleep.

For example, at the lowest sound level tested, 40 dB, intravenous alarm and phone signals aroused 88-94% of subjects; human voices aroused 70-75% of subjects; the sounds of an automatic towel dispenser, ice dispenser, door closing and toilet flushing aroused 35-73% of subjects.”

Source: Landmark Sound-Sleep Study Pinpoints Decibel Levels at Which Typical Hospital Sounds are Too Loud for Sleep

Original Study: Evidence-Based Design Meets Evidence-Based Medicine: The Sound Sleep Study

Solet, J. M., Buxton. O.M., Ellenbogen, J.M., Wang, W., and Carballiera, A. (2010).
Evidence-based design meets evidence-based medicine: The sound sleep study.
Concord, CA: The Center for Health Design.

Low-Level Hospital Noise and Effect on Sleep

In this study, researchers tested sounds played at different decibel levels. Take a minute and read that actual article. It’s not very long, and has good information. Keep in mind, you need to review all studies and information with concussion in mind. It hasn’t been addressed as far as I know. You’re going to have to connect the dots yourself.

“Certain hospital sounds, such as electronic alarms, telephones and conversations, can wake patients up even at relatively low levels, creating an environment that may slow healing, according to a U.S. study.

………

“For instance, during moderately light levels of sleep – where people spend most of the night – an IV pump alarm woke up about 90 percent of people at 40 dB, the quietest level. Even during deep sleep, more than half of people woke up to the alarm played at the level of a whisper.

Similarly, about three-quarters of participants woke up from the sound of people having a whispered conversation during the lighter stage of sleep, the researchers said.”

………

“All of the patients were healthy and not in the hospital, and Ellenbogen, also from Harvard Medical School, said he would expect to see an even greater disturbance among older and sicker hospitalized patients.”

Source: Low-Level Hospital Noise May Disrupt Sleep: Study
Reuters.com
June 11, 2012

Effect of Noise on Sleep

This study has excellent information. You should read this in its entirety as well. The main takeaways for me were the intermittent noises and effect on sleeping and information about how daytime noise exposure affects sleep.

“Good sleep is fundamental for good physiological and mental health (9). Difficulty in falling asleep, intermittent wakefulness, light sleep, difficulty in going back to sleep and early morning waking are the main indicators to determine the level of sleep disturbance.”

“Sleep disturbance has been classified into delay of sleep onset or awakening from sleep in the middle of the night or early morning. Besides causing awakening, noise also makes the stages of sleep shallower, reducing the feeling of rejuvenation after sleep. The specifications of noise, such as the loudness, duration and pattern of change, is very important in clarifying the effects of noise on sleep. For example, intermittent noise has more adverse effects than continuous noise.”

“Exposure to noise in the daytime makes subsequent sleep worse (27).”

Noise and Health—Sleep Disturbance in Adults
Tomoyuki Kawada
Department of Hygiene and Public Health, Nippon Medical School, Japan
Journal of Occupational Health, J Occup Health 2011; 53: 413–416

Lower Threshold of Noise Tolerance

My assertion is that concussees experience difficulties at a lower threshold of noise exposure. One cause of hyperacusis is head injury.

Update: 2/23/13: Note re hyperacusis – please take a look at the comments for this post. Michelle has shared some great information about that. I’ve learned much just from her comments re first-hand experience with it.

Update July 17, 2018: Removed references to hyperacusis information from an audiologist’s website and a standalone website, and the information is no longer available. Added link to hyperacusis information on a medical association website.

Decibel Levels

With the lower threshold idea in mind, I’d like you to consider this fact about decibel levels. They’re recorded on a logarithmic scale.

“Sound is measured in units called decibels. Decibel levels begin at zero, which is near total silence and the weakest sound our ears can hear. By comparison, a whisper is 30 decibels and a normal conversation is 60 decibels. An increase of 10 means that a sound is 10 times more intense, or powerful. To your ears, it sounds twice as loud. The sound of an ambulance siren at 120 decibels is about 1 trillion times more intense than the weakest sound our ears can hear.

How Loud is Too Loud? How Long is Too Long?
National Institutes of Health

Here is some information about increases in decibel levels affect people.

Perceived change in decibel level
+/1 10dB – Twice (or half) as loud
+/1 20 dB – Fourfold (4x) change

Human Perception of Sound
Modular Wall Systems

My questions: does this somehow intensify for a concussee? If they have a lower threshold (as noted by Dr. Johnson) might the impact increase as well? In other words, would a 10 dB increase (double) actually seem like a 20 dB increase (quadruple) for a concussee? Again,  I have no idea.

Heart Rate

Noise increases heart rate. There are references to that everywhere. Just search a bit and you’ll find information.

Cardiovascular Disturbances

Here’s an excerpt from the article that provides an excellent overview of health issues related to noise.

“4. Cardiovascular Disturbances:  A growing body of evidence confirms that noise pollution has both temporary and permanent effects on humans (and other mammals) by way of the endocrine and autonomic nervous systems.  It has been postulated that noise acts as a nonspecific biologic stressor eliciting reactions that prepare the body for a “fight or flight” response. ^{1, 2, 6}  For this reason, noise can trigger both endocrine and autonomic nervous system responses that affect the cardiovascular system and thus may be a risk factor for cardiovascular disease. ^{1, 2, 6, 11, 33- 36} 

Noise Pollution: A Modern Plague
Lisa Goines, RN and Louis Hagler, MD
Southern Medical Journal, Volume 100: March 2007, pages 287-294

Effects of Excessive Noise Exposure

“Other effects of excessive noise exposure may include:

• Quickened pulse rate; increased blood pressure; and narrowing of the body’s blood vessels as a result of noise may, over a long period of time, place an added burden on the heart.
• Abnormal secretion of hormones.
• Muscle tension.
• Ulcers.
• Loss of sleep.
• Fatigue.
• Stress reactions.”

OSHA Noise and Hearing Conservation – Appendix I:C Effects of Excessive Exposure

Autoregulatory Issues

Increased heart rate due to noise must affect autoregulation, I would imagine. My question is: what if you’re exposed to a high decibel level for even a short period, such as lunch in a noisy cafeteria? Wouldn’t that increase your heart rate? Wouldn’t it then possibly affect autoregulation and cause concussion symptoms to worsen? The study above mentions the autonomic nervous system. Here’s more about autoregulatory issues.

“Cerebral autoregulation (the capacity to maintain cerebral blood flow at a relatively constant level during changes in systemic blood pressure) and cerebral blood flow are also disturbed after concussion [42,69], which may explain why concussion symptoms often re-appear or worsen with physical exertion or other stress, as the brain’s ability to maintain constant blood flow in the face of fluctuating mean arterial blood pressure is impaired after concussion [42].”

Regulatory and autoregulatory physiological dysfunction as a primary characteristic of post-concussion syndrome: Implications for Treatment
John J. Leddy (a), Karl Kozlowski (b), Michael Fung (a), David R. Pendergast (a) and Barry Willer (a)
(a) State University of New York at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY, USA
(b) State University of New York at Buffalo School of Public Health and Health Professions, Buffalo, NY, USA

Note:  I must say that I’m a former patient of Dr. Leddy and the UB Concussion Clinic. Back when I was going through my recovery, they were the only ones I found that were looking at physical causes of concussion. Everywhere else I looked really focused only or mainly on neuropsychology. They set up an exercise program for me and I’m sure it helped me. So I’m a strong believer in their program. At the time of publishing this post, they also don’t know I’m writing this. To a certain degree, it was their work that led me down this path. They set up a program where you exert to a specific level that’s below the heart rate at which you experience symptoms. That’s why I think it’s important to determine decibel level thresholds per individual and then designating a level below that to stay within. Perhaps it would work in the same manner. For more information about that, please review this post of mine: Concussions Post-Injury: Noise as Cause of Symptoms.

Noise at Sporting Events

The louder the better. That’s what’s expected at sporting events. For football games, cities and fans pride themselves on who has the loudest stadium, the loudest noise to impair visiting teams.  Many are the times I’ve seen graphics on the jumbotrons at various events that say one word: Noise. That is to encourage you to yell and make it difficult for the opposing team to concentrate or hear calls. Which everyone then does at that moment, right on cue, as instructed.  I’ve done so myself. Who hasn’t? At basketball games, people stamp their feet and yell to try and interrupt a player’s concentration when they’re making a critical free throw. Hockey – well I’ll just say that I don’t believe that rinks are designed for acoustics.

Noise. Deafening, distracting noise.

It’s a critical part of the game.

What if you have a concussion, or are a player with a concussion? How do you handle that environment? Do you have worse symptoms after attending such an event? That day? The next day? It’s not unusual for a concussee to feel well one day, go do some activities or just get back to their own life, only to have some bad days that immediately follow. Paying the price, so to speak. Just ask someone you know that has a concussion. So I wonder. If someone feels better one day, goes to a noisy sporting event or some other gathering, and then feels awful the next day, could the excess noise have been a factor? Could there be some kind of residual effect? I have no idea. I’m just tossing that out for consideration.

References

Study about noise and decibel levels at sporting events, including soccer and stock car races:

“Fans are lucky to attend a game or two, but what about the players, event staff, stadium workers, broadcasters and referees who are repeatedly exposed to the noise? These levels exceed most national and international standards on permissible exposure limits.”

“A recent paper from NIOSH looked at noise exposures in stock car racing. The study found that that noise levels on three race tracks exceeded those measured in many hazardous industrial environments. ”

— CDC: Vuvuzelas: What’s the Buzz?

…………..

I recently attended a high school basketball game. Talk about noise! A gym full of teenagers, a band, lots of folks cheering. It was loud. So, I pulled out my phone and checked my decibel level apps (I use two). The dB level in the gym was 80 – 100+ dB. Imagine, now, if you’re a student with a concussion and you go to a game with your friends.  How might you feel later that evening, or the next day? Will all that noise have impacted you? Will it result in a bad day the following day, or make it more difficult to sleep that evening? Based on all my research so far, it would not surprise me if it did. That’s something I’d like to check on with some experts.

Migraines

Some concussees experience migraines daily. Can noise be both a cause of migraines and a symptom?

“Sensitivity to sound is a frequent migraine symptom. About three quarters of migraine suffers complain of sound sensitivity. It is the third most common migraine symptom behind throbbing pain and sensitivity to light.  About 77 percent of females and 70 percent of males experience sound sensitivity with migraine attacks.”

“Sufferers may complain that migraines make noises louder”
– Migraine.com: Sensitivity to Sound

Can noise abatement steps reduce the number of migraines or migraine intensity? Migraines are complex, no doubt and I’m no expert. But….  maybe focusing on reducing noise exposure would help in some way. Why not look at that?

Personal and Home Noise Abatement

In industry, manufacturing in particular, there are noise abatement programs mandated by law and regulatory requirements. These are definitely at the federal level and oftentimes at the state level as well. Essential components include administrative and engineering controls to reduce noise in the workplace. Engineering controls are adjustments or additions to pieces of equipment to minimize noise on that particular machine. Administrative controls are processes and procedures to follow. When dealing with concussion, think of this. The brain is the machine, the piece of equipment. What are some engineering and administrative controls you can implement  to minimize noise exposure? Here are some thoughts, examples, and suggestions that I have.

Engineering

• Noise-cancelling headphones
• Earplugs*
• Window plugs on windows
• Solid-core doors instead of hollow-core doors on a room
• Insulated curtains or drapes
• Appliances set away from walls or set on a open shelf, not closed

Administrative

• An hour before retiring for the evening, go to a quiet room and turn everything off.
• Check decibel levels in your environment and determine what you can handle and adjust activities accordingly.
• At school: eat lunch in the nurse’s office, or some other room with a lower decibel level than that of the cafeteria. See if you can wait until the bell rings and then go to the next class so you’re not in a noisy, high-decibel level hallway. Sit in the front row of your class to enhance your chance of hearing more and increasing concentration (see the TED talk). Work in the quiet library instead of a noisy classroom, if possible. Maybe a teacher can simply close the door to their classroom (if not doing so already) to block noise from the hallway.
• At work or home: use headphones and listen to sounds/music to disguise noise as indicated in the TED talk.

Think about it. In libraries, you’re supposed to whisper. Keep quiet. Why? To make it easier to read, comprehend, and digest material. During standardized tests such as SATs, absolute silence is required. All you hear is the faint sound of pages being turned and perhaps some number 2 pencils and erasers in action. Why? You really need to concentrate. So why put a concussee into a noisy cafeteria, hallway, or classroom when noise could exacerbate symptoms? Why? What administrative controls can you implement? What can you do at home, school, and work to mitigate noise exposure?

* You probably should check with a doctor if you’re thinking of using earplugs. Please see the first comments below for more information about that. Plus they can be tricky to put in; you should learn how to do so properly.

References

Excellent reference on home noise abatement options as well as diagrams and information about sound
Controlling Home Noise: Basics for Beginners

Information about window plugs and more
Do It Yourself Home Soundproofing

Occupational Safety and Health Administration (OSHA) hearing conservation guidelines and requirements:

• Information on engineering and administrative controls for industry; good examples:
  OSHA: Occupational Noise Exposure

• Laws and regulations regarding hearing conservation. Companies are required to develop hearing conservation programs.
  OSHA Occupational Noise Exposure Regulatory Standards

 

Current Thinking

In the concussion world, I don’t believe that noise is considered much.  Yes, it’s included on lists of symptoms everywhere. However, it’s not discussed in much detail anywhere. Look at any medical site focusing on concussion, and you just won’t find much. Not yet, anyway. What I found earlier, I’ve had to remove from this post as the information is no longer available.

Updated: July 2, 2014 Removed reference to the University of Washington information on noise on the Traumatic Brain Injury page, as the page had been updated and the references removed.

Updated: July 17, 2018: Removed references to materials on CDC, Mayo Clinic, and an audiologist’s sites, as some information has changed. From what I’ve seen, there isn’t yet much focus on noise and decibel level management.

Summary

The more I look into noise and think about it, the more I’m convinced. Noise is key. It is a cause, not a smaller side symptom. Management of decibel level exposure and noise abatement could have a positive effect on recovery. That’s my thought, anyway.

I’m connecting dots. Hopefully you will as well. Let’s start looking at noise as a cause of concussion symptoms. Let’s review the existing noise data of the last few decades. I know there’s information out there. Let’s take a look at it and start reviewing it from the concussion angle. Let’s get some studies going that focus on noise and concussion. Noise is a major piece of the puzzle. Instead of wondering how to manage concussions or looking at pills to throw at the problem, not knowing if they’ll even work, perhaps you can start with some simple noise abatement steps.

To the medical community

Please look long and hard at noise as a cause of other concussion symptoms. People are really suffering out there from noise. I’ve heard about it. People have posted about their difficulties. Plus there are decades worth of studies and data available. Just look. I’ve tried to find information about concussion and noise, but haven’t had any luck yet.

To concussees and caregivers

I think that you’re still on your own with this. The medical community is paying attention to concussion now, but I think it’ll still take a while. So read up on this, track decibel levels yourself, and talk to your doctor about it. At home, look into noise abatement. At school or work, see if any of the items in the Abatement section above might help. I think you’ll need to be proactive on this one. And definitely keep in mind that there are wide ranges of approach to this issue, as noted in the Current Thinking section.

To everyone

I really think that the cognitive tests are like report cards. They can identify the areas which need work. Concussees everywhere are flunking their noise classes, so to speak. Maybe if you help or get help with that, those overall grades will improve. 😉

Related Post

This is my post that discusses decibel level tracking and provides more information about how noise affects or creates additional concussion symptoms. I think it’s important to review, so please take a look. You might find some helpful information.

Concussions Post-Injury: Noise as Cause of Symptoms