"Some low-frequency sounds--such as noise from storms or truck engines--can make you feel dizzy and nauseated. An index finger's light touch can stop people from losing balance. You are more prone to trip when you think someone is watching you. A breakthrough in improving balance as we age might just come through the study of the Achilles tendon. A person gets "falling down drunk" due to a tiny structure in the inner ear that floats when it becomes...