Image Image Image Image Image Image Image Image Image Image

Zidbits – Learn something new everyday! | September 15, 2014

Scroll to top

Top

12 Comments

What Causes Spontaneous Ringing In Our Ears?

What Causes Spontaneous Ringing In Our Ears?

It happens to everyone. All of the sudden, with no warning or apparent cause, one or both of your ears starts to ring. A seemingly high pitched sound that can be distracting at times. Sometimes lasting for just a few minutes, other times lasting for hours. We wanted to know what causes this annoying phenomena, and if there are ways to prevent it from happening.

A Brief Public Service Announcement

We would like to let our readers know that if you’re experiencing a ringing in one ear which will not go away (unilateral tinnitus), you should seek the advice of a medical professional, like your primary care physician. He or she may refer you to an audiologist who specializes in tinnitus. Unilateral tinnitus may be the result of something more serious than the occasional tinnitus we describe below.

How Do We Hear?

Before we can understand how and why tinnitus occurs, we need to know how we hear. More specifically, we need to know how the ear turns vibrations in the air into electrical signals, signals which our brain processes then interprets as sound. This starts with the mammalian cochlea.

inner hair cellThe mammalian cochlea has two types of sensory hair cell; the outer and inner hair cells. These cells are what detects then converts vibrations or movement into electrical signals. When a sound enter the ear, it causes pressure fluctuations within the inner ear. The inner ear is filled with fluids, fluids which help facilitate the transfer of these vibrations. They vibrate down a thin, spiral trampoline-like structure called the basilar membrane. When this membrane moves, even slightly, it is detected by the inner hair cells. These cells are located on top of the basilar membrane. When they detect these vibrations, they relay the signals to the brain via the auditory nerve.

While sound vibrations travel efficiently through the liquid in your inner ear, it doesn’t do so without cost. If you have ever tried to run in a pool or in water, you know it’s much more difficult than running on land thanks to the viscosity and friction of water. This is where the outer hair cells shine. Like inner hair cells, they also detect movement on the basilar membrane. However unlike the inner hair cells, they are capable of producing vibrations themselves. Instead of sending a bunch of signals to the brain, possibly over stimulating it, their job is to expand and contract in time with the vibrations they detect. This cancels out the friction and amplifies the sound by a factor of 100 to 1,000. Thanks to the outer hair cells, our hearing sensitivity is increased by 40-60 dB (decibels). Notably, in the higher frequency ranges.

So What Causes The Ringing?

When the outer hair cells put energy back into the vibration, it’s called positive feedback or “saturation feedback”. The process is meant to amplify very quiet sounds more so than loud ones. Most of the time, it works great and you go on with your life, not noticing anything out of the ordinary. However, biological systems aren’t always flawless. Occasionally, the amplification level of one or more outer hair cells will go awry and as a result, the whole system will erupt into spontaneous oscillation.

When this occurs, it becomes audible to us (we hear it). We perceive it as a ringing in the ear, or “sudden-onset ringing tinnitus”. As with most of our biological systems, there are quite a few homestatic control mechanisms (negative feedback loops) which exist to correct the problem and get rid of the unpleasant oscillation. Biology Tight RopeNerves whose job it is to tell the auditory nerve and/or hair cells to cut it out. It takes roughly 30 seconds for this mechanism to begin to do its thing and send the required messages which suppress the ringing. After the message is sent and received, the tinnitus percept begins to fade away. You can tell when this reaction has taken place as its often accompanied by a slight reduction in hearing sensitivity (like background or ambient noise we hear suddenly getting quieter), followed by a feeling of fullness in the ear. It usually takes about a minute for this process to fully complete.

Our ears are walking a tightrope in high winds. While want our ear’s gain turned up high to maximize our hearing, we also don’t want the spontaneous oscillations that come with the increased sensitivity. If you stop and think about it, it’s amazing that our regulatory mechanisms work well enough that ringing doesn’t happen more often. The human body is more amazing than we give it credit for.

Why Is Your Hearing Less When Yawning?

Your ear muscles emit a quiet, low-frequency sound when they contract. When you yawn, your muscles around the middle ear are contracting (specifically, the tensor veli palatini). This causes a dull roar from the muscle contraction and is also responsible clicking or popping sounds you may hear from your Eustachian tubes opening.

When the Eustachian tubes open, the pressure around them goes down. This lowering of pressure not only causes the rumbling or subtle roaring noises to lessen, but all of your hearing is temporarily decreased until the yawn is over and the Eustachian tubes close.

Other interesting facts:

  • Under ideal acoustic circumstances (in a soundproof room having an ambient noise level of 17 dB or less), slight tinnitus is present in 80 to 90% of all adults.
  • Fish don’t have ears, but they can “hear” pressure changes in water through ridges on their body.
  • In WW1, parrots were kept on the Eiffel Tower in France because of their keen sense of hearing. When an enemy aircraft was approaching, the parrots would warn everyone of the impending danger.
  • Your ears contain over 25,000 inner & outer hair cells.

References:
Jan Schnupp, Israel Nelken and Andrew King (2011). Auditory Neuroscience. MIT Press. ISBN 0-262-11318-X
Nicolas-Puel C, Faulconbridge RL, Guitton M, Puel JL, Mondain M, Uziel A (2002). “Characteristics of tinnitus and etiology of associated hearing loss: a study of 123 patients”. The international tinnitus journal 8 (1): 37–44
Daniel Schacter, Daniel Gilbert, Daniel Wegner (2011). “Sensation and Perception”. In Charles Linsmeiser. Psychology. Worth Publishers. p. 158-159.
Manley GA, Popper AN, Fay RR (2004). Evolution of the Vertebrate Auditory System. New York: Springer-Verlag. ISBN 0-387-21093-8.

Comments

  1. TiagoTiago

    Nice to know. I was worried it meant my ear hairs were dying from hearing loud things (but the ringing doesn’t happen specifically right after any loud noises, just spontaneously – especially in quiet rooms, and doesn’t last for too long, exactly as described here).

    PS: But don’t worry, I will mention it anyway next time I talk with my ear doctor.

  2. I also have ringing in the ears. I can tell you this, it is not tinnitus. I only hear it in my home where there are unknown R.F. signals being beamed into my bedroom. I say unknown because I have R.F. detection equipment and the beam is not coming from outside my home. When I leave the house, the ringing goes away. It may be coming in from the roof, but I didn’t want to go up there. Do you live next to one of the hundreds of cell towers? That may be your problem.

    • Carin

      The sound you hear may be coming from a feedback from your TV, or other appliances. This often occurs in buildings with older wiring. Try listening to the room without anything turned-on. Then, see if the sound goes away when the appliance (i.e. TV) is turned-on.

    • Hard Target

      A few months ago an acquaintance casually stated that if he hears a high pitched sound he just assumes a TV was turned on. The statement had no relevance to anything discussed at the time. Shortly after, I started hearing a ringing in my left ear but only at home. Odd eh? It could be that the meters on the house are near my bedroom window. But it could also be some form of electronic harassment being done by a vicious neighbor. Just a thought.

  3. linda

    I have ringing in my ears. I live by 3 towers. As soon I get home they start ringing. It start with a high pitch, then low. It depends on the towers. Sometimes the pitch is so high it hurts my ears. This happens all day and night. The ringing doesn’t stop until I leave my house then I’m ok. As soon I get close it starts again.

    • I think between the cell towers and now the new digital electric “smart” meters, I have this tinnitus. Also sometimes hissing, crackling sounds. I have a log of when the smart meter transmits data as at those times it gives off a sound like old fashioned telephone ringing, my pets can hear it too. Smart meters plus cell towers are a disaster.

  4. Ruby

    I have a continually long ring in my right ear and it stays until I rub it, and THEN it goes away. I have two problems that I am concerned about, my right eye twitching and my ear w/ the ringing. I have had this happen ever since I was about 3 years old. Both were there and never went away. I have tried everything for the eye but nothing seems to cure the ear and I can’t go to an audiologist to check it out because I’m moving in the near by future… What should I do if the audiologist doesn’t find anything wrong but its still there?

  5. Eric

    I work in the trades, it’s noisy. I go home, turn the lights off, and it’s quite time, I can here a slight ringing in the ears,This I know is perfectly normal. However there are times when my dog will all of a sudden just go crazy barking, along with the dogs in the neighborhood. In the meantime, I’m looking to see what there barking at (naturally) and there’s nothing. During this time there is a loud ringing in the ears for about 20 seconds. This I find very odd, and simply don’t understand. This may sound weird but there has to be something at play causing this, I just don’t know what.

  6. Heather

    What are RF signals?

    • mary

      RF. They are radio frequency signals. They are harmless.

  7. Greg

    Does this happen to anyone else? When I purposely push out my jaw, simulating a severe under bite, I get a high-pitched constant tone in my ears. It stops as soon as I return my jaw to its normal position. This doesn’t happen when opening my mouth normally. Any suggestions? Thanks.

    • Yes, this happens to me as well. I do this whenever I get the ringing in my ears. It seems to overpower it and afterwards, I hear a fan-like sound that fades away in 5-15 seconds. It usually takes the constant ringing away.

Submit a Comment

Pinterest