A specific medical condition called Superior canal dehiscence syndrome (SCDS) cause disorders in hearing as well in balance. It is very rare and is studied for the first time in the Johns Hopkins University in USA by Dr. Lloyd B. Minor. The disease affects inner ear when part of the temporal bone is very thin or completely missing. Studies show that this defect is most probably innate.
Some of the symptoms include dizziness, headache, high sensitivity to sound, disequilibrium and vertigo. Probably the most curious symptom is hearing inner sounds (like person’s own voice, movements of the eye, chewing) extremely loudly. Patients are reported to hear their own voice very loud and distorted, like it’s coming from a damaged loudspeaker. Usually they can hear their own heartbeat, eye movements (when they look to different walls in a quiet room or when reading for example), chewing, cracking of joints and noises from the digestive system. Another common symptom of the condition is brain fatigue, because the brain uses great amount of energy to maintain the whole body in equilibrium – something that comes natural for the unaffected people.