The most common injuries divers experience are ear injuries. Not fully understanding the anatomy of the ear, or pushing your diving safety limits, can greatly enhance your risk of encountering an issue. UW360, along with the Diver’s Alert Network Asia-Pacific (DAN Asia-Pacific) Medical Team, investigate the causes and symptoms of ear injuries when diving – and how to reduce the risks.
Ear Injuries and Potential Risks
An ear injury can lead to complete or partial hearing loss, which can occur for a variety of reasons. There are several diving-related causes, including barotrauma, decompression sickness (DCS), and damage to the inner ear.
Hearing loss can be classified as conductive or sensorineural:
- Conductive hearing loss involves the ear canal, eardrum and tiny bones of the middle-ear ossicles; these anatomical components mechanically conduct sound to the inner ear, where electrical signals are generated
- Sensorineural hearing loss involves the brain, the eighth cranial nerve or the inner ear
Causes, Signs, and Lessons
There are many causes of ear injuries in diving, including infection, blocked ear canals, barotrauma, and drugs. One of the major causes is a difference in pressure between the external environment and the internal parts of the ear. Since fluids do not compress under pressure experienced during diving, the fluid-containing spaces of the ear do not alter their volume under this pressure change. However, the air-containing spaces of the ear do compress, resulting in damage to the ear if the alterations in ambient pressure cannot be equalised. Bottom line – make sure you equalise diligently.
It’s worth paying attention to your ears when you’re diving. If you feel pain on your descent, do not force yourself to dive deeper. Follow the simple steps of ascending to relieve pressure, and if you still can’t equalise then abort the dive. Medication before a dive should be taken with caution. The dive manual states not to take sinus medications – but many divers bypass this instruction and still do.
The more extreme diving-related ear injury, hearing loss, is mainly limited to commercial divers exposed to loud noises and to divers who have experienced barotrauma of the ear. Recreational divers who equalise appropriately and dive without any ear injuries are often not at risk of losing their hearing. The onus falls on the diver themselves: Are they fit to dive?
Fit to Dive?
Although extremely uncommon, dive-related permanent hearing loss resulting from ear barotrauma or inner-ear DCS is possible. If the injury causes permanent unilateral (one ear only) hearing loss or impairment, most physicians will advise against a return to diving. This is often recommended because if subsequent diving resulted in injury to the remaining functioning ear, the individual may experience permanent bilateral hearing loss. This recommendation applies to all monaural (one-sided hearing) individuals, regardless of the cause of unilateral hearing loss or impairment.
An additional population for whom diving is often discouraged, or extreme caution is advised, includes those who have undergone cochlear-implant surgery, ossicle surgery or tympanic-membrane repair (myringoplasty). Diving places individuals with this medical history at risk of damaging the surgical repair, resulting in hearing loss. For divers who have undergone such procedures, or suffered permanent hearing loss from ear barotrauma, extreme caution is often recommended, and close consultation with an ear, nose and throat (ENT) physician prior to diving is highly advised.