Divers are vulnerable to a variety of ear problems. When water collects and remains in the external ear canal for some time, infections can occur. Bony growths can develop in the external canal when divers are continually exposed to cold water.
Ears have several parts, each with its own unique set of diving related disorders. The external ear includes the ear itself and the canal leading to the eardrum. The eardrum separates the external from the middle and inner ear.
EXTERNAL EAR PROBLEMS
The ear structure can be injured by trauma. Feeding fish U/W sometimes invites a nip on the ear by a dissatisfied customer. Occasionally, a fish bite becomes severe enough to require treatment.
SWIMMER’S EAR. External canal infections, sometimes called swimmer’s ear, occur when water accumulates and remains long enough to allow bacteria and fungus to grow. This is best prevented by removing water from the ear canal. You know when there’s water in there because a rumbling sound will be heard when you move your head. Prevention of external infections is best done by using a commercial drying solution such as Otic Domeboro or Auro-Dri. A few drops in each ear before and after water exposure is adequate.
EXOSTOSES. When divers are constantly exposed to cold water, bony growths, called exostoses, may develop in the external ear canal. They will ultimately grow large enough to block the canal, causing diminished hearing and infections because water cannot drain. Both ear canals are involved but the eardrum is rarely, if ever, affected. These growths are not tumors. Some experts think they are a natural reaction to prevent cold water from reaching the eardrum. Ending the cold water exposure usually stops the growth but the growths do not disappear when the cold stimulus is removed. If they become large and block the ear canal, they must be removed surgically but there is a risk of damage to the eardrum and to nerves that control the facial muscles. Covering the ear canals with a hood when exposed to cold water can help in prevention. The hood will trap water and allow it to warm enough to avoid cold irritation.
Exostoses are easily diagnosed. A physician can see them when examining the external ear canal with an otoscope.
MIDDLE EAR PROBLEMS
The middle ear includes the chamber behind the eardrum, which contains the small bones of the ear that transmit sound to the hearing organ. Connected into the middle ear is the eustachian tube from the throat – necessary for pressure equalization – and the mastoid cells, which are spaces in the bone of the skull. The middle ear is easily injured by barotrauma (squeeze) and is susceptible to infection.
EAR SQUEEZE. Ear squeeze, with injury to the eardrum, is the most common diving related illness. Difficulty clearing or equalizing the ears is a problem that every diver has experienced. It occurs when you cannot open the eustachian tubes to allow air to enter the middle ear and balance the pressure across the eardrum (see the ear diagram). To avoid ear squeeze, be sure there is no congestion in your nose or throat when you dive. Begin clearing your ears on the surface, before you descend, and continue to clear every foot or two as you go down. Waiting for ear pain to occur before you try to equalize is a bad habit. Usually, you will be unable to clear the blocked ear at this stage. You must ascend three or four feet, equalize, then try another descent.
Besides causing direct injury to the eardrum, middle ear squeeze produces a swelling of the lining of the middle ear and eustachian tube plus fluid and blood accumulation in the middle ear. Often, the fluid will persist until the swelling has subsided and normal eustachian tube function returns. This frequently requires five or six days and occasionally one to two weeks. The presence of other factors, such as nasal allergy or irritation from smoking, can prolong the recovery period. With middle ear fluid accumulation, sound is not transmitted properly to the inner ear but it still responds to noises present in the head that are usually masked by outside sounds. Thus, an occasional hissing or buzzing can be heard. Hissing or buzzing following an ear squeeze may indicate middle ear or inner ear injury. If these sounds are not accompanied by other inner ear injury symptoms – such as vertigo or hearing loss – are not loud or are intermittent, they are probably related to middle ear squeeze.
As mentioned above, squeeze can be avoided by clearing the ears every foot or two during descent. When a squeeze occurs, there is some damage to the eardrum. If the damage is severe and ear problems persist for several days, medical attention should be sought. Most middle ear squeeze can be successfully treated with medication but you should not dive until the ear is completely clear.
INFECTIONS. A blocked middle ear owing to eustachian tube obstruction, repeated ear squeeze or water entering the middle ear from a perforated eardrum, can result in a middle ear infection, permanent perforation of the eardrum and reduced hearing. These consequences are fully preventable by careful attention to ear equalization when diving. If your ears won’t equalize, don’t dive until they do. If you have repeated trouble equalizing, have an ear and nose evaluation by a specialist to determine the reason.
INNER EAR PROBLEMS
The inner ear consists of the hearing (auditory) and balance (vestibular) organs and their nerve connections to the brain. The inner ear is connected to the spinal fluid space and, when injured, can allow infection to spread into the brain. The inner ear is separated from the middle ear by the round and oval windows. Injuries to the middle ear include round window rupture, inner ear decompression sickness and vestibular decompression sickness.
ROUND WINDOW RUPTURE. A more serious barotrauma related to diving is rupture of the round window (RWR). You can cause RWR by forcefully trying to equalize during descent. By doing a Valsalva maneuver to equalize, you raise the pressure in the inner ear above ambient pressure. If the eustachian tube is blocked, the middle ear pressure will be below ambient and the large pressure difference can blow out the round window. When the round window tears, fluid from the inner ear leaks into the middle ear. This fluid normally stabilizes both the hearing and the balance organs. When fluid is lost, hearing is lost; vertigo occurs and hissing or buzzing is heard constantly. The tear in the round window can heal itself but surgery is often needed to correct the problem. If repair is incomplete, permanent partial hearing loss is likely and diving is no longer recommended. This injury, like middle ear squeeze, is totally preventable.
INNER EAR DECOMPRESSION SICKNESS (DCS). Rarely, DCS can occur in the inner ear and cause permanent hearing loss or permanent abnormalities in balance. This injury is characterized by sudden total hearing loss in one ear following a dive. Inner ear DCS usually occurs in commercial divers after deep saturation diving. One case of suspected inner ear DCS was recounted in a sport diver but considering the larger number of sport divers and the questionable diagnosis, there should be no concern for inner ear DCS in sport diving. If other symptoms, such as hearing loss, vertigo, dizziness or loud roaring or ringing noises are present, you should promptly consult an ENT (ear, nose and throat) specialist.
PERFORATED EARDRUM. You should not dive with a perforated eardrum. Sometimes cold water entering the middle ear through a perforated eardrum will upset the balance mechanism next to the middle ear and cause sudden vertigo, dizziness or even vomiting. None of these things are conducive to safe diving. As noted above, a hole in your eardrum will allow water to enter the middle ear and cause an infection. However, most eardrum perforations caused by diving are not permanent. If you rupture an eardrum, you should see a physician, get treatment to prevent ear infection and wait for healing to occur. You may be unable to dive for three to four weeks but with proper care, the drum will heal. After your doctor’s approval, you should be able to dive again.
Chronic eardrum perforations usually occur when there is poor eustachian tube function. Unless the tube functions properly, the perforation will not heal. Frequently, poor eustachian tube function is related to allergy or chronic sinus infection. Individuals who have a permanent perforation should consult an ENT specialist. They should not dive until the causes of poor eustachian tube function have been adequately treated and the eardrum perforation has been repaired.
Divers need to be aware that most chronic middle ear disease results from poor eustachian tube function. Many nondivers have these problems. Anyone who has inadequate eustachian tube function will develop middle and, possibly, inner ear barotrauma when exposed to the ambient pressure changes encountered in diving.
PREVENTING EAR INJURY. The problem with equalizing originates from the inside of the ears and throat. You should learn the various ways to clear your ears. If you still have trouble after using the correct method of clearing, have an ear, nose and throat exam by a doctor who knows diving medicine. Before seeking more medical advice, try the following: descend in the water feet first; begin to clear your ears on the surface before you begin your descent; and clear continuously as you descend. Be careful not to bear down too hard or you will risk a round window rupture.
When diving, all the tissues of the body are subjected to the increased pressure of the surrounding water. The ears cannot be excluded from the ambient pressure of diving and, because their function is to detect the minuscule pressure changes caused by sound, they are the weakest link among the pressure sensitive organs. You are likely to experience ear problems sometime during your diving lifetime. Protection of your ears during diving requires careful attention to the health of your nose and throat and to your descent and ascent techniques.